Self-Regulation and Implicit Attitudes Toward Physical Activity Influence Exercise Behavior.
Padin, Avelina C; Emery, Charles F; Vasey, Michael; Kiecolt-Glaser, Janice K
2017-08-01
Dual-process models of health behavior posit that implicit and explicit attitudes independently drive healthy behaviors. Prior evidence indicates that implicit attitudes may be related to weekly physical activity (PA) levels, but the extent to which self-regulation attenuates this link remains unknown. This study examined the associations between implicit attitudes and self-reported PA during leisure time among 150 highly active young adults and evaluated the extent to which effortful control (one aspect of self-regulation) moderated this relationship. Results indicated that implicit attitudes toward exercise were unrelated to average workout length among individuals with higher effortful control. However, those with lower effortful control and more negative implicit attitudes reported shorter average exercise sessions compared with those with more positive attitudes. Implicit and explicit attitudes were unrelated to total weekly PA. A combination of poorer self-regulation and negative implicit attitudes may leave individuals vulnerable to mental and physical health consequences of low PA.
Trying to trust: Brain activity during interpersonal social attitude change.
Filkowski, Megan M; Anderson, Ian W; Haas, Brian W
2016-04-01
Interpersonal trust and distrust are important components of human social interaction. Although several studies have shown that brain function is associated with either trusting or distrusting others, very little is known regarding brain function during the control of social attitudes, including trust and distrust. This study was designed to investigate the neural mechanisms involved when people attempt to control their attitudes of trust or distrust toward another person. We used a novel control-of-attitudes fMRI task, which involved explicit instructions to control attitudes of interpersonal trust and distrust. Control of trust or distrust was operationally defined as changes in trustworthiness evaluations of neutral faces before and after the control-of-attitudes fMRI task. Overall, participants (n = 60) evaluated faces paired with the distrust instruction as being less trustworthy than faces paired with the trust instruction following the control-of-distrust task. Within the brain, both the control-of-trust and control-of-distrust conditions were associated with increased temporoparietal junction, precuneus (PrC), inferior frontal gyrus (IFG), and medial prefrontal cortex activity. Individual differences in the control of trust were associated with PrC activity, and individual differences in the control of distrust were associated with IFG activity. Together, these findings identify a brain network involved in the explicit control of distrust and trust and indicate that the PrC and IFG may serve to consolidate interpersonal social attitudes.
Using Science Activities To Internalize Locus of Control and Influence Attitudes towards Science.
ERIC Educational Resources Information Center
Rowland, Paul McD.
This study investigated the relationships between science activities that emphasize cause-and-effect and a learner's locus of control. Pretests included the Nowicki-Strickland Abbreviated Scale 7-12 to measure locus of control, and a modification of the Test of Science Related Attitudes to measure attitudes toward science. The findings suggest…
An Experimental Study of an Ultra-Mobile Vehicle for Off-Road Transportation.
1983-02-01
Control with Active Compliance ....... 97 ( 5.5 Force Tracking .... ................. .... 97 5.6 Attitude Sensor Evaluation .. ........... . .101 6...93 5.7 OSU Hexapod Traversing Obstacle ............ ... 95 - 5.8 Vehicle Attitude Across Obstacle Using No Terrain- Adaptive ...Underspecified Gait Using Attitude Control and Active Compliance 100 5.12 Foot Force Tracking Using Active Compliance in an Underspecified Gait
NASA Technical Reports Server (NTRS)
Sindlinger, R. S.
1977-01-01
A 3-axis active attitude control system with only one rotating part was developed using a momentum wheel with magnetic gimballing capability as a torque actuator for all three body axes. A brief description of magnetic bearing technology is given. It is concluded that based on this technology an integrated energy storage/attitude control system with one air of counterrotating rings could reduce the complexity and weight of conventional systems.
Improvement of helicopter attitude stability by active control of the conventional swash plate
NASA Technical Reports Server (NTRS)
Ham, Norman D.
1993-01-01
The Final Report on improvement of helicopter attitude stability by active control of the conventional swash plate covering the period from Nov. 1986 to Dec. 1993 is presented. A paper on the history, principles, and applications of helicopter individual-blade-control is included.
RECOGNIZING FARMERS' ATTITUDES AND IMPLEMENTING NONPOINT SOURCE POLLUTION CONTROL POLICIES
This report examines the role of farmer attitudes and corresponding communication activities in the implementation of nonpoint source water pollution control programs. The report begins with an examination of the basis for and function of attitudes in influencing behavior. The ro...
Satellite Dynamic Damping via Active Force Control Augmentation
NASA Astrophysics Data System (ADS)
Varatharajoo, Renuganth
2012-07-01
An approach that incorporates the Active Force Control (AFC) technique into a conventional Proportional-Derivative (PD) controller is proposed for a satellite active dynamic damping towards a full attitude control. The AFC method has been established to facilitate a robust motion control of dynamical systems in the presence of disturbances, parametric uncertainties and changes that are commonly prevalent in the real-world environment. The usefulness of the method can be extended by introducing intelligent mechanisms to approximate the mass or inertia matrix of the dynamic system to trigger the compensation effect of the controller. AFC is a technique that relies on the appropriate estimation of the inertial or mass parameters of the dynamic system and the measurements of the acceleration and force signals induced by the system if practical implementation is ever considered. In AFC, it is shown that the system subjected to a number of disturbances remains stable and robust via the compensating action of the control strategy. We demonstrate that it is possible to design a spacecraft attitude feedback controller that will ensure the system dynamics set point remains unchanged even in the presence of the disturbances provided that the actual disturbances can be modeled effectively. In order to further facilitate this analysis, a combined energy and attitude control system (CEACS) is proposed as a model satellite attitude control actuator. All the governing equations are established and the proposed satellite attitude control architecture is made amenable to numerical treatments. The results show that the PD-AFC attitude damping performances are superiorly better than that of the solely PD type. It is also shown that the tunings of the AFC system gains are crucial to ensure a better attitude damping performance and this process is mandatory for AFC systems. Finally, the results demonstrate an important satellite dynamic damping enhancement capability using the AFC technique. Keywords: Satellite, Dynamic Damping, Attitude Control, AFC Technique,
Integrated Attitude Control Strategy for the Asteroid Redirect Mission
NASA Technical Reports Server (NTRS)
Lopez, Pedro, Jr.; Price, Hoppy; San Martin, Miguel
2014-01-01
A deep-space mission has been proposed to redirect an asteroid to a distant retrograde orbit around the moon using a robotic vehicle, the Asteroid Redirect Vehicle (ARV). In this orbit, astronauts will rendezvous with the ARV using the Orion spacecraft. The integrated attitude control concept that Orion will use for approach and docking and for mated operations will be described. Details of the ARV's attitude control system and its associated constraints for redirecting the asteroid to the distant retrograde orbit around the moon will be provided. Once Orion is docked to the ARV, an overall description of the mated stack attitude during all phases of the mission will be presented using a coordinate system that was developed for this mission. Next, the thermal and power constraints of both the ARV and Orion will be discussed as well as how they are used to define the optimal integrated stack attitude. Lastly, the lighting and communications constraints necessary for the crew's extravehicular activity planned to retrieve samples from the asteroid will be examined. Similarly, the joint attitude control strategy that employs both the Orion and the ARV attitude control assets prior, during, and after each extravehicular activity will also be thoroughly discussed.
Satellite recovery - Attitude dynamics of the targets
NASA Technical Reports Server (NTRS)
Cochran, J. E., Jr.; Lahr, B. S.
1986-01-01
The problems of categorizing and modeling the attitude dynamics of uncontrolled artificial earth satellites which may be targets in recovery attempts are addressed. Methods of classification presented are based on satellite rotational kinetic energy, rotational angular momentum and orbit and on the type of control present prior to the benign failure of the control system. The use of approximate analytical solutions and 'exact' numerical solutions to the equations governing satellite attitude motions to predict uncontrolled attitude motion is considered. Analytical and numerical results are presented for the evolution of satellite attitude motions after active control termination.
Attitude control system conceptual design for the GOES-N spacecraft series
NASA Technical Reports Server (NTRS)
Markley, F. L.; Bauer, F. H.; Deily, J. J.; Femiano, M. D.
1991-01-01
The attitude determination sensing and processing of the system are considered, and inertial reference units, star trackers, and beacons and landmarks are discussed as well as an extended Kalman filter and expected attitude-determination performance. The baseline controller is overviewed, and a spacecraft motion compensation (SMC) algorithm, disturbance environment, and SMC performance expectations are covered. Detailed simulation results are presented, and emphasis is placed on dynamic models, attitude estimation and control, and SMC disturbance accommmodation. It is shown that the attitude control system employing gyro/star tracker sensing and active three-axis control with reaction wheels is capable of maintaining attitude errors of 1.7 microrad or less on all axes in the absence of attitude disturbances, and that the sensor line-of-sight pointing errors can be reduced to 0.1 microrad by SMC.
NASA Astrophysics Data System (ADS)
Li, Decang; Meng, Jianjun; Bai, Huan; Xu, Ruxun
2018-07-01
This paper focuses on the safety of high-speed trains under strong crosswind conditions. A new active control strategy is proposed based on the adaptive predictive control theory. The new control strategy aims at adjusting the attitudes of a train by controlling the new-type intelligent giant magnetostrictive actuator (GMA). It combined adaptive control with dynamic matrix control; parameters of predictive controller was real-time adjusted by online distinguishing to enhance the robustness of the control algorithm. On this basis, a correction control algorithm is also designed to regulate the parameters of predictive controller based on the step response of a controlled objective. Finally, the simulation results show that the proposed control strategy can adjust the running attitudes of high-speed trains under strong crosswind conditions; they also indicate that the new active control strategy is effective and applicable in improving the safety performance of a train based on a host-target computer technology provided by Matlab/Simulink.
NASA Astrophysics Data System (ADS)
Acar Sesen, Burcin; Tarhan, Leman
2013-02-01
This study aimed to investigate the effects of inquiry-based laboratory activities on high school students' understanding of electrochemistry and attitudes towards chemistry and laboratory work. The participants were 62 high school students (average age 17 years) in an urban public high school in Turkey. Students were assigned to experimental ( N = 30) and control groups ( N = 32). The experimental group was taught using inquiry-based laboratory activities developed by the researchers and the control group was instructed using traditional laboratory activities. The results of the study indicated that instruction based on inquiry-based laboratory activities caused a significantly better acquisition of scientific concepts related to electrochemistry, and produced significantly higher positive attitudes towards chemistry and laboratory. In the light of the findings, it is suggested that inquiry-based laboratory activities should be developed and applied to promote students' understanding in chemistry subjects and to improve their positive attitudes.
Chevance, Guillaume; Héraud, Nelly; Varray, Alain; Boiché, Julie
2017-05-01
The aim of this study was twofold: (a) to determine whether Theory of Planned Behavior (TPB) variables and implicit attitudes toward physical activity and sedentary behavior would change during a 5-week pulmonary rehabilitation (PR) program, and (b) to investigate the relationships between behavioral intentions, implicit attitudes, physical activity, and sedentary behavior in postrehabilitation. Out of 142 patients with respiratory disease included in this study, 119 completed 2 questionnaires measuring TPB variables with regard to physical activity and sedentary behavior, and an Implicit Association Test (IAT) measuring implicit attitudes toward physical activity in contrast to sedentary behavior. The TPB questionnaires and the IAT were administered at the beginning (Time 1) and the end of the program (Time 2). Six months after the program (Time 3), 62 patients provided self-reported measures of their recreational physical activity and screen-based, leisure-time sedentary behavior. Over the course of pulmonary rehabilitation, perceived behavioral control and intentions toward physical activity increased, as did social norms and perceived behavioral control toward sedentary behavior; implicit attitudes were also more positive toward physical activity. Implicit attitudes at the end of PR (Time 2) were significantly associated with postrehabilitation physical activity (Time 3). TPB variables toward physical activity and sedentary behavior as well as implicit attitudes were enhanced during PR. At 6 months, implicit attitudes were significantly associated with physical activity. These results suggest that motivation, particularly implicit attitudes, should be targeted in future behavioral interventions in order to optimize the effects of rehabilitation on physical activity maintenance. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Goodall, Catherine E.; Slater, Michael D.
2010-01-01
Alcohol advertisements may influence impulsive, risky behaviors indirectly, via automatically-activated attitudes toward alcohol. Results from an experiment in which participants were exposed to either four alcohol advertisements, four control advertisements, or four drunk driving public service advertisements, suggested that alcohol advertisements had more measurable effects on implicit, than on explicit attitude measures. Moreover, there were significant indirect paths from alcohol advertisement exposure through automatically-activated alcohol attitudes on willingness to engage in risky alcohol-related behaviors, notably drinking and driving. A mechanism that may explain how these advertisements activate automatic, non-deliberative alcohol attitudes was investigated. Associative evidence was found supportive of an evaluative conditioning mechanism, in which positive responses to an alcohol advertisement may lead to more positive automatically-activated attitudes toward alcohol itself. PMID:21258609
Goodall, Catherine E; Slater, Michael D
2010-10-01
Alcohol advertisements may influence impulsive, risky behaviors indirectly, via automatically-activated attitudes toward alcohol. Results from an experiment in which participants were exposed to either four alcohol advertisements, four control advertisements, or four drunk driving public service advertisements, suggested that alcohol advertisements had more measurable effects on implicit, than on explicit attitude measures. Moreover, there were significant indirect paths from alcohol advertisement exposure through automatically-activated alcohol attitudes on willingness to engage in risky alcohol-related behaviors, notably drinking and driving. A mechanism that may explain how these advertisements activate automatic, non-deliberative alcohol attitudes was investigated. Associative evidence was found supportive of an evaluative conditioning mechanism, in which positive responses to an alcohol advertisement may lead to more positive automatically-activated attitudes toward alcohol itself.
ERIC Educational Resources Information Center
Smith, Mike U.; Katner, Harold P.
This study was conducted to assess the level of AIDS-related knowledge, attitudes, and risk behaviors of a group of predominantly sexually active high school seniors (N=734) and to evaluate the relative effectiveness of three AIDS prevention activities in improving knowledge, attitudes, and behaviors among these students. The educational program…
Examination of psychological variables related to nuclear attitudes and nuclear activism
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roy, P.J.
1985-01-01
It was hypothesized that knowledge about nuclear arms developments would not be correlated with nuclear attitudes, that sense of efficacy would be positively correlated with magnitude of nuclear activism, and that death anxiety would be correlated with high level of nuclear knowledge and anti-nuclear attitudes, but not with sense of power. It was also hypothesized that positive correlations would be found between nuclear activism and political activism, knowledge of nuclear facts, and degree of adherence to anti-nuclear attitudes. One hundred and forty three women and 90 men participated in this questionnaire study. Major findings are as follows. In general, themore » more people knew about nuclear developments, the more anti-nuclear were their attitudes. Also, regardless of nuclear attitudes, a positive correlation was found between knowledge of nuclear facts and nuclear activism. Death anxiety and powerlessness were not correlated. There was a positive correlation between anxiety and both nuclear knowledge and anti-nuclear attitudes. A strong positive correlation was found between nuclear activism and anti-nuclear attitudes, and between political activism and nuclear activism. Internal locus of control did not correlate significantly with high sense of power or with high degree of nuclear activism.« less
A national internet survey on midlife women's attitudes toward physical activity.
Im, Eun-Ok; Chang, Sun Ju; Ko, Young; Chee, Wonshik; Stuifbergen, Alexa; Walker, Lorraine
2012-01-01
Despite an increasing number of studies of midlife women's physical activity, little is known about how attitudes toward physical activity of midlife women from diverse ethnic groups influence the women's physical activity. To explore ethnic differences in midlife women's attitudes toward physical activity and determine the relationships between the attitudes and their actual participation in physical activity while considering other influencing factors. The Midlife Women's Attitudes Toward Physical Activity model was used to guide the study. This was a cross-sectional Internet survey study of 542 midlife women. The instruments included questions on background characteristics and health and menopausal status; the Physical Activity Assessment Inventory; a modified Barriers to Health Activities Scale; the Questions on Attitudes Toward Physical Activity, Subjective Norm, Perceived Behavioral Control, and Behavioral Intention; and the Kaiser Physical Activity Survey. The data were analyzed using ANOVA, correlation, hierarchical multiple regression, and path analyses. There were significant ethnic differences in the attitude scores (F = 2.58, p < .05), but no ethnic differences in the physical activity scores. Interestingly, there were significant ethnic differences in the occupational physical activity scores (F = 5.68, p < .01). Attitude scores accounted for 5% of total variances of the physical activity scores (F(ch) = 43.52, p < .01). The direct paths from the attitude scores (p < .01), the self-efficacy scores (p < .01), and the barrier scores (p < .05) to the physical activity scores were statistically significant. Ethnic differences in the women's attitudes toward physical activity need to be considered in promoting physical activity of midlife women.
Attitude analysis of the Earth Radiation Budget Satellite (ERBS) yaw turn anomaly
NASA Technical Reports Server (NTRS)
Kronenwetter, J.; Phenneger, M.; Weaver, William L.
1988-01-01
The July 2 Earth Radiation Budget Satellite (ERBS) hydrazine thruster-controlled yaw inversion maneuver resulted in a 2.1 deg/sec attitude spin. This mode continued for 150 minutes until the spacecraft was inertially despun using the hydrazine thrusters. The spacecraft remained in a low-rate Y-axis spin of .06 deg/sec for 3 hours until the B-DOT control mode was activated. After 5 hours in this mode, the spacecraft Y-axis was aligned to the orbit normal, and the spacecraft was commanded to the mission mode of attitude control. This work presents the experience of real-time attitude determination support following analysis using the playback telemetry tape recorded for 7 hours from the start of the attitude control anomaly.
Yun, Young Ho; Han, Kyung Hee; Park, Sohee; Park, Byeong Woo; Cho, Chi-Heum; Kim, Sung; Lee, Dae Ho; Lee, Soon Nam; Lee, Eun Sook; Kang, Jung Hun; Kim, Si-Young; Lee, Jung Lim; Heo, Dae Seog; Lee, Chang Geol; Lim, Yeun Keun; Kim, Sam Yong; Choi, Jong Soo; Jeong, Hyun Sik; Chun, Mison
2011-01-01
Background: Whereas most studies have focused on euthanasia and physician-assisted suicide, few have dealt comprehensively with other critical interventions administered at the end of life. We surveyed cancer patients, family caregivers, oncologists and members of the general public to determine their attitudes toward such interventions. Methods: We administered a questionnaire to four groups about their attitudes toward five end-of-life interventions — withdrawal of futile life-sustaining treatment, active pain control, withholding of life-sustaining measures, active euthanasia and physician-assisted suicide. We performed multivariable analyses to compare attitudes and to identify sociodemographic characteristics associated with the attitudes. Results: A total of 3840 individuals — 1242 cancer patients, 1289 family caregivers and 303 oncologists from 17 hospitals, as well as 1006 members of the general Korean population — participated in the survey. A large majority in each of the groups supported withdrawal of futile life-sustaining treatment (87.1%–94.0%) and use of active pain control (89.0%–98.4%). A smaller majority (60.8%–76.0%) supported withholding of life-sustaining treatment. About 50% of those in the patient and general population groups supported active euthanasia or physician-assisted suicide, as compared with less than 40% of the family caregivers and less than 10% of the oncologists. Higher income was significantly associated with approval of the withdrawal of futile life-sustaining treatment and the practice of active pain control. Older age, male sex and having no religion were significantly associated with approval of withholding of life-sustaining measures. Older age, male sex, having no religion and lower education level were significantly associated with approval of active euthanasia and physician-assisted suicide. Interpretation: Although the various participant groups shared the same attitude toward futile and ameliorative end-of-life care (the withdrawal of futile life-sustaining treatment and the use of active pain control), oncologists had a more negative attitude than those in the other groups toward the active ending of life (euthanasia and physician-assisted suicide). PMID:21624907
NASA Technical Reports Server (NTRS)
Sindlinger, R. S.
1977-01-01
Magnetic bearings used for the suspension of momentum wheels provide conclusive advantages: the low friction torques and the absence of abrasion allow the realization of lightweight high speed wheels with high angular momentum and energy storage capacity and virtually unlimited lifetime. The use of actively controlled bearings provides a magnetic gimballing capability by applying the external signals to the two servo loops controlling the rotational degrees of freedom. Thus, an attitude control system can be realized by using only one rotating mass for 3-axis active satellite stabilization.
Weight Control Beliefs, Body Shape Attitudes, and Physical Activity among Adolescents
ERIC Educational Resources Information Center
Martin, Scott B.; Rhea, Deborah J.; Greenleaf, Christy A.; Judd, Doryce E.; Chambliss, Heather O.
2011-01-01
Background: Relatively little is known about how perceived weight controllability influences important psychological health factors among adolescents. Thus, the purpose of this study is to explore adolescents' weight controllability beliefs and how those beliefs influence weight-related attitudes and behaviors. Methods: Adolescents (N = 369, mean…
ATTDES: An Expert System for Satellite Attitude Determination and Control. 2
NASA Technical Reports Server (NTRS)
Mackison, Donald L.; Gifford, Kevin
1996-01-01
The design, analysis, and flight operations of satellite attitude determintion and attitude control systems require extensive mathematical formulations, optimization studies, and computer simulation. This is best done by an analyst with extensive education and experience. The development of programs such as ATTDES permit the use of advanced techniques by those with less experience. Typical tasks include the mission analysis to select stabilization and damping schemes, attitude determination sensors and algorithms, and control system designs to meet program requirements. ATTDES is a system that includes all of these activities, including high fidelity orbit environment models that can be used for preliminary analysis, parameter selection, stabilization schemes, the development of estimators covariance analyses, and optimization, and can support ongoing orbit activities. The modification of existing simulations to model new configurations for these purposes can be an expensive, time consuming activity that becomes a pacing item in the development and operation of such new systems. The use of an integrated tool such as ATTDES significantly reduces the effort and time required for these tasks.
NASA Astrophysics Data System (ADS)
Frey, Jesse
In recent years there has been a growing interest in smaller satellites. Smaller satellites are cheaper to build and launch than larger satellites. One form factor, the CubeSat, is especially popular with universities and is a 10~cm cube. Being smaller means that the mass and power budgets are tighter and as such new ways must be developed to cope with these constraints. Traditional attitude control systems often use reaction wheels with gas thrusters which present challenges on a CubeSat. Many CubeSats use magnetic attitude control which uses the Earth's magnetic field to torque the satellite into the proper orientation. Magnetic attitude control systems fall into two main categories: active and passive. Active control is often achieved by running current through a coil to produce a dipole moment, while passive control uses the dipole moment from permanent magnets that consume no power. This thesis describes a system that uses twelve hard magnetic torquers along with a magnetometer. The torquers only consume current when their dipole moment is flipped, thereby significantly reducing power requirements compared with traditional active control. The main focus of this thesis is on the design, testing and fabrication of CubeSat hardware and software in preparation for launch.
An investigation of quasi-inertial attitude control for a solar power satellite
NASA Technical Reports Server (NTRS)
Juang, J.-N.; Wang, S. J.
1982-01-01
An efficient means, a quasi-inertial attitude mode, is developed for maintaining the normal solar orientation of a space satellite for power collection in a synchronous orbit. Formulae are presented which establish the basic parametric properties for ideal quasi-inertial attitude and phasing. An active control system is necessary to compensate for the energy loss since energy dissipation in widely oscillating flexible bodies produces an instability of the quasi-inertial attitude in the sense that the spacecraft will tumble at the orbit rate. A fixed terminal time and state optimal control problem is formulated and an algorithm for determining the optimal control as a means for the periodical attitude and phase compensation is developed. The vehicle orientation affected by internal disturbance (structural flexibility) and external disturbances (e.g., drag forces) is maintained by a specialized controller design.
Geçkil, Emine; Kaleci, Elanur; Cingil, Dilek; Hisar, Filiz
2017-02-01
Nurses care for disabled people in society. The aim of this experimental study was to investigate the effect of disability empathy activities on strengthening the positive attitudes of nursing students towards disabled people. An experimental study. Pretest-Posttest control group arrangement was used. This research has been conducted with 116 nursing students (53 experimental and 63 control). The data were collected with "Attitudes Towards Disabled Persons Scale" (ATDP). Before the experiment, there was no significant difference between ATDP scores of experimental and control groups (p > 0.05). After the experiment, second ATDP scores of experimental group (66.81 ± 14.27) were found to be significantly higher than the scores of control group (59.02 ± 11.71) (p = 0.002). After six months, third ATDP scores of experimental group (63.58 ± 13.46) were also found to be higher than the scores of control group (58.43 ± 11.03) (p = 0.025). Empathy activities applied to understand disabled people affected the attitudes of student nurses towards disabled people positively.
Kerner, Matthew S; Kalinski, Michael I
2002-08-01
Using the Theory of Planned Behavior as a framework, the Attitude to Leisure-time Physical Activity, Expectations of Others, Perceived Control, and Intention of Engage in Leisure-time Physical Activity scales were developed for use among high school students. The study population included 20 boys and 68 girls 13 to 17 years of age (for boys, M = 15.1 yr., SD = 1.0; for girls, M = 15.0 yr., SD = 1.1). Generation of items and the establishment of content validity were performed by professionals in exercise physiology, physical education, and clinical psychology. Each scale item was phrased in a Likert-type format. Both unipolar and bipolar scales with seven response choices were developed. Following the pilot testing and subsequent revisions, 32 items were retained in the Attitude to Leisure-time Physical Activity scale, 10 items were retained in the Expectations of Others scale, 3 items were retained in the Perceived Control Scale, and 24 items were retained in the Intention to Engage in Leisure-time Physical Activity scale. Coefficients indicated adequate stability and internal consistency with alpha ranging from .81 to .96. Studies of validities are underway, after which scales would be made available to those interested in intervention techniques for promoting positive attitudes toward physical fitness, perception of control over engaging in leisure-time physical activities, and good intentions to engage in leisure-time physical activities. The present results are encouraging.
NASA Astrophysics Data System (ADS)
Whitcher, Carrie Lynn
2005-08-01
Adolescence is marked with many changes in the development of higher order thinking skills. As students enter high school they are expected to utilize these skills to solve problems, become abstract thinkers, and contribute to society. The goal of this study was to assess horticultural science knowledge achievement and attitude toward horticulture, science, and school in high school agriculture students. There were approximately 240 high school students in the sample including both experimental and control groups from California and Washington. Students in the experimental group participated in an educational program called "Hands-On Hortscience" which emphasized problem solving in investigation and experimentation activities with greenhouse plants, soilless media, and fertilizers. Students in the control group were taught by the subject matter method. The activities included in the Hands-On Hortscience curriculum were created to reinforce teaching the scientific method through the context of horticulture. The objectives included evaluating whether the students participating in the Hands-On Hortscience experimental group benefited in the areas of science literacy, data acquisition and analysis, and attitude toward horticulture, science, and school. Pre-tests were administered in both the experimental and control groups prior to the research activities and post-tests were administered after completion. The survey questionnaire included a biographical section and attitude survey. Significant increases in hortscience achievement were found from pre-test to post-test in both control and experimental study groups. The experimental treatment group had statistically higher achievement scores than the control group in the two areas tested: scientific method (p=0.0016) and horticulture plant nutrition (p=0.0004). In addition, the students participating in the Hands-On Hortscience activities had more positive attitudes toward horticulture, science, and school (p=0.0033). Students who were more actively involved in hands-on projects had higher attitude scores compared to students who were taught traditional methods alone. In demographic comparisons, females had more positive attitudes toward horticulture science than males; and students from varying ethnic backgrounds had statistically different achievement (p=0.0001). Ethnicity was determined with few students in each background, 8 in one ethnicity and 10 students in another. Youth organization membership such as FFA or 4-H had no significant bearing on achievement or attitude.
Hu, Qinglei
2007-10-01
This paper presents a dual-stage control system design method for the flexible spacecraft attitude maneuvering control by use of on-off thrusters and active vibration control by input shaper. In this design approach, attitude control system and vibration suppression were designed separately using lower order model. As a stepping stone, an integral variable structure controller with the assumption of knowing the upper bounds of the mismatched lumped perturbation has been designed which ensures exponential convergence of attitude angle and angular velocity in the presence of bounded uncertainty/disturbances. To reconstruct estimates of the system states for use in a full information variable structure control law, an asymptotic variable structure observer is also employed. In addition, the thruster output is modulated in pulse-width pulse-frequency so that the output profile is similar to the continuous control histories. For actively suppressing the induced vibration, the input shaping technique is used to modify the existing command so that less vibration will be caused by the command itself, which only requires information about the vibration frequency and damping of the closed-loop system. The rationale behind this hybrid control scheme is that the integral variable structure controller can achieve good precision pointing, even in the presence of uncertainties/disturbances, whereas the shaped input attenuator is applied to actively suppress the undesirable vibrations excited by the rapid maneuvers. Simulation results for the spacecraft model show precise attitude control and vibration suppression.
Application Number 3: Using Tethers for Attitude Control
NASA Technical Reports Server (NTRS)
Muller, R. M.
1985-01-01
Past application of the gravity gradient concept to satellite attitude control produced attitude stabilities of from 1 to 10 degrees. The satellite members were rigigly interconnected and any motion in one part of the satellite would cause motion in all members. This experience has restricted gravity gradient stabilization to applications that need attitude stability no better than 1 degree. A gravity gradient technique that combines the flexible tether with an active control that will allow control stability much better than 1 degree is proposed. This could give gravity gradient stabilization much broader application. In fact, for a large structure like a space station, it may become the preferred method. Two possible ways of demonstrating the techniques using the Tethered Satellite System (TSS) tether to control the attitude of the shuttle are proposed. Then a possible space station tether configuration is shown that could be used to control the initial station. It is then shown how the technique can be extended to the control of space stations of virtually any size.
GOES-R active vibration damping controller design, implementation, and on-orbit performance
NASA Astrophysics Data System (ADS)
Clapp, Brian R.; Weigl, Harald J.; Goodzeit, Neil E.; Carter, Delano R.; Rood, Timothy J.
2018-01-01
GOES-R series spacecraft feature a number of flexible appendages with modal frequencies below 3.0 Hz which, if excited by spacecraft disturbances, can be sources of undesirable jitter perturbing spacecraft pointing. To meet GOES-R pointing stability requirements, the spacecraft flight software implements an Active Vibration Damping (AVD) rate control law which acts in parallel with the nadir point attitude control law. The AVD controller commands spacecraft reaction wheel actuators based upon Inertial Measurement Unit (IMU) inputs to provide additional damping for spacecraft structural modes below 3.0 Hz which vary with solar wing angle. A GOES-R spacecraft dynamics and attitude control system identified model is constructed from pseudo-random reaction wheel torque commands and IMU angular rate response measurements occurring over a single orbit during spacecraft post-deployment activities. The identified Fourier model is computed on the ground, uplinked to the spacecraft flight computer, and the AVD controller filter coefficients are periodically computed on-board from the Fourier model. Consequently, the AVD controller formulation is based not upon pre-launch simulation model estimates but upon on-orbit nadir point attitude control and time-varying spacecraft dynamics. GOES-R high-fidelity time domain simulation results herein demonstrate the accuracy of the AVD identified Fourier model relative to the pre-launch spacecraft dynamics and control truth model. The AVD controller on-board the GOES-16 spacecraft achieves more than a ten-fold increase in structural mode damping for the fundamental solar wing mode while maintaining controller stability margins and ensuring that the nadir point attitude control bandwidth does not fall below 0.02 Hz. On-orbit GOES-16 spacecraft appendage modal frequencies and damping ratios are quantified based upon the AVD system identification, and the increase in modal damping provided by the AVD controller for each structural mode is presented. The GOES-16 spacecraft AVD controller frequency domain stability margins and nadir point attitude control bandwidth are presented along with on-orbit time domain disturbance response performance.
GOES-R Active Vibration Damping Controller Design, Implementation, and On-Orbit Performance
NASA Technical Reports Server (NTRS)
Clapp, Brian R.; Weigl, Harald J.; Goodzeit, Neil E.; Carter, Delano R.; Rood, Timothy J.
2017-01-01
GOES-R series spacecraft feature a number of flexible appendages with modal frequencies below 3.0 Hz which, if excited by spacecraft disturbances, can be sources of undesirable jitter perturbing spacecraft pointing. In order to meet GOES-R pointing stability requirements, the spacecraft flight software implements an Active Vibration Damping (AVD) rate control law which acts in parallel with the nadir point attitude control law. The AVD controller commands spacecraft reaction wheel actuators based upon Inertial Measurement Unit (IMU) inputs to provide additional damping for spacecraft structural modes below 3.0 Hz which vary with solar wing angle. A GOES-R spacecraft dynamics and attitude control system identified model is constructed from pseudo-random reaction wheel torque commands and IMU angular rate response measurements occurring over a single orbit during spacecraft post-deployment activities. The identified Fourier model is computed on the ground, uplinked to the spacecraft flight computer, and the AVD controller filter coefficients are periodically computed on-board from the Fourier model. Consequently, the AVD controller formulation is based not upon pre-launch simulation model estimates but upon on-orbit nadir point attitude control and time-varying spacecraft dynamics. GOES-R high-fidelity time domain simulation results herein demonstrate the accuracy of the AVD identified Fourier model relative to the pre-launch spacecraft dynamics and control truth model. The AVD controller on-board the GOES-16 spacecraft achieves more than a ten-fold increase in structural mode damping of the fundamental solar wing mode while maintaining controller stability margins and ensuring that the nadir point attitude control bandwidth does not fall below 0.02 Hz. On-orbit GOES-16 spacecraft appendage modal frequencies and damping ratios are quantified based upon the AVD system identification, and the increase in modal damping provided by the AVD controller for each structural mode is presented. The GOES-16 spacecraft AVD controller frequency domain stability margins and nadir point attitude control bandwidth are presented along with on-orbit time domain disturbance response performance.
Anderson, Cheryl B; Hughes, Sheryl O; Fuemmeler, Bernard F
2009-07-01
This study examined parent-child attitudes on value of specific types and intensities of physical activity, which may explain gender differences in child activity, and evaluated physical activity as a mechanism to reduce time spent in sedentary behaviors. A community sample of 681 parents and 433 children (mean age 9.9 years) reported attitudes on importance of vigorous and moderate intensity team and individually performed sports/activities, as well as household chores. Separate structural models (LISREL 8.7) for girls and boys tested whether parental attitudes were related to child TV and computer via child attitudes, sport team participation, and physical activity, controlling for demographic factors. Child 7-day physical activity, sport teams, weekly TV, computer. Parent-child attitude congruence was more prevalent among boys, and attitudes varied by ethnicity, parent education, and number of children. Positive parent-child attitudes for vigorous team sports were related to increased team participation and physical activity, as well as reduced TV and computer in boys and girls. Value of moderate intensity household chores, such as cleaning house and doing laundry, was related to decreased team participation and increased TV in boys. Only organized team sports, not general physical activity, was related to reduced TV and computer. Results support parents' role in socializing children's achievement task values, affecting child activity by transferring specific attitudes. Value of vigorous intensity sports provided the most benefits to activity and reduction of sedentary behavior, while valuing household chores had unexpected negative effects.
Predicting Physical Activity Promotion in Health Care Settings.
ERIC Educational Resources Information Center
Faulkner, Guy; Biddle, Stuart
2001-01-01
Tested the theory of planned behavior's (TPB) ability to predict stage of change for physical activity promotion among health professionals. Researchers measured attitudes, subjective norms, intentions, perceived behavioral control, and stage of change, then later reassessed stage of change. TPB variables of attitude, subjective norms, perceived…
Active control and synchronization chaotic satellite via the geomagnetic Lorentz force
NASA Astrophysics Data System (ADS)
Abdel-Aziz, Yehia
2016-07-01
The use of geomagnetic Lorentz force is considered in this paper for the purpose of satellite attitude control. A satellite with an electrostatic charge will interact with the Earth's magnetic field and experience the Lorentz force. An analytical attitude control and synchronization two identical chaotic satellite systems with different initial condition Master/ Slave are proposed to allows a charged satellite remains near the desired attitude. Asymptotic stability for the closed-loop system are investigated by means of Lyapunov stability theorem. The control feasibility depend on the charge requirement. Given a significantly and sufficiently accurate insertion, a charged satellite could maintains the desired attitude orientation without propellant. Simulations is performed to prove the efficacy of the proposed method.
Johnson, Ray; Simon, Elizabeth J; Henkell, Heather; Zhu, John
2011-04-01
Event-related potentials (ERPs) are unique in their ability to provide information about the timing of activity in the neural networks that perform complex cognitive processes. Given the dearth of extant data from normal controls on the question of whether attitude representations are stored in episodic or semantic memory, the goal here was to study the nature of the memory representations used during conscious attitude evaluations. Thus, we recorded ERPs while participants performed three tasks: attitude evaluations (i.e., agree/disagree), autobiographical cued recall (i.e., You/Not You) and semantic evaluations (i.e., active/inactive). The key finding was that the parietal episodic memory (EM) effect, a well-established correlate of episodic recollection, was elicited by both attitude evaluations and autobiographical retrievals. By contrast, semantic evaluations of the same attitude items elicited less parietal activity, like that elicited by Not You cues, which only access semantic memory. In accord with hemodynamic results, attitude evaluations and autobiographical retrievals also produced overlapping patterns of slow potential (SP) activity from 500 to 900ms preceding the response over left and right inferior frontal, anterior medial frontal and occipital brain areas. Significantly different patterns of SP activity were elicited in these locations for semantic evaluations and Not You cues. Taken together, the results indicate that attitude representations are stored in episodic memory. Retrieval timing varied as a function of task, with earlier retrievals in both evaluation conditions relative to those in the autobiographical condition. The differential roles and timing of memory retrieval in evaluative judgment and memory retrieval tasks are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.
Psychological interventions influence patients' attitudes and beliefs about their chronic pain.
Vanhaudenhuyse, Audrey; Gillet, Aline; Malaise, Nicole; Salamun, Irène; Grosdent, Stéphanie; Maquet, Didier; Nyssen, Anne-Sophie; Faymonville, Marie-Elisabeth
2018-04-01
Patients' changing attitudes and beliefs about pain are considered as improvements in the treatment of chronic pain. Multidisciplinary approaches to pain allow modifications of coping strategies of patients, from passive to active. We investigate how two therapeutic treatments impact patients' attitudes and beliefs regarding pain, as measured with the Survey of Pain Attitudes (SOPA). We allocated 415 patients with chronic pain either to psychoeducation combined with physiotherapy, self-hypnosis combined with self-care learning, or to control groups. Pain intensity, global impression of change, and beliefs and attitudes regarding pain were assessed before and after treatment. Our main results showed a significant effect of psychoeducation/physiotherapy on control, harm, and medical cure SOPA subscales; and a significant effect of self-hypnosis/self-care on control, disability and medical cure subscales. Correlation results showed that pain perception was negatively associated with control, while positively associated with disability, and a belief that hurt signifies harm. Patients' impression of improvement was associated with greater control, lower disability, and lower belief that hurt signifies harm. The present study showed that self-hypnosis/self-care and psychoeducation/physiotherapy were associated with patients' evolution of coping strategies from passive to active, allowing them to reduce pain perception and improve their global impression of treatment effectiveness.
Community Involvement, Perceived Control, and Attitudes toward Aging among Lesbians and Gay Men
ERIC Educational Resources Information Center
Hostetler, Andrew J.
2012-01-01
A person-environment approach was used to explore the relationship between community involvement and attitudes toward aging among middle-age and older lesbians and gay men. Specifically, this study investigated the relationships between participation in gay community activities, perceived control, and aging-related concerns among two…
Magsat attitude dynamics and control: Some observations and explanations
NASA Technical Reports Server (NTRS)
Stengle, T. H.
1980-01-01
Before its reentry 7 months after launch, Magsat transmitted an abundance of valuable data for mapping the Earth's magnetic field. As an added benefit, a wealth of attitude data for study by spacecraft dynamicists was also collected. Because of its unique configuration, Magsat presented new control problems. With its aerodynamic trim boom, attitude control was given an added dimension. Minimization of attitude drift, which could be mapped in relative detail, became the goal. Momentum control, which was accomplished by pitching the spacecraft in order to balance aerodynamic and gravity gradient torques, was seldom difficult to achieve. Several interesting phenomena observed as part of this activity included occasional momentum wheel instability and a rough correlation between solar flux and the pitch angle required to maintain acceptable momentum. An overview is presented of the attitude behavior of Magsat and some of the control problems encountered. Plausible explanations for some of this behavior are offered. Some of the control philosophy used during the mission is examined and aerodynamic trimming operations are summarized.
The effect of active learning on student characteristics in a human physiology course for nonmajors.
Wilke, R Russell
2003-12-01
This study investigated the effect of active-learning strategies on college students' achievement, motivation, and self-efficacy in a human physiology course for nonmajors. Variables were studied via a quasi-experimental, Solomon four-group design on 141 students at a small west-Texas university. Treatment groups were taught using a continuum-based, active-learning model implemented over the course of a semester. Control groups were taught using traditional didactic lecture methods. To assess the effects of the continuum-based active learning strategies, students were administered a comprehensive physiology content exam, the Motivated Strategies for Learning Questionnaire, and attitude surveys. Factorial analyses indicated that the treatment groups acquired significantly more content knowledge and were significantly more self-efficacious than students in the control groups. There were no significant differences in motivation. Attitude surveys indicated that students in both the treatment and control groups demonstrated a positive attitude toward active learning, believed it helped (or would help) them to learn the material, and would choose an active learning course in the future.
Nature and operation of attitudes.
Ajzen, I
2001-01-01
This survey of attitude theory and research published between 1996 and 1999 covers the conceptualization of attitude, attitude formation and activation, attitude structure and function, and the attitude-behavior relation. Research regarding the expectancy-value model of attitude is considered, as are the roles of accessible beliefs and affective versus cognitive processes in the formation of attitudes. The survey reviews research on attitude strength and its antecedents and consequences, and covers progress made on the assessment of attitudinal ambivalence and its effects. Also considered is research on automatic attitude activation, attitude functions, and the relation of attitudes to broader values. A large number of studies dealt with the relation between attitudes and behavior. Research revealing additional moderators of this relation is reviewed, as are theory and research on the link between intentions and actions. Most work in this context was devoted to issues raised by the theories of reasoned action and planned behavior. The present review highlights the nature of perceived behavioral control, the relative importance of attitudes and subjective norms, the utility of adding more predictors, and the roles of prior behavior and habit.
Demonstration of Single Axis Combined Attitude Control and Energy Storage Using Two Flywheels
NASA Technical Reports Server (NTRS)
Kenny, Barbara H.; Jansen, Ralph; Kascak, Peter; Dever, Timothy; Santiago, Walter
2004-01-01
The energy storage and attitude control subsystems of the typical satellite are presently distinct and separate. Energy storage is conventionally provided by batteries, either NiCd or NiH, and active attitude control is accomplished with control moment gyros (CMGs) or reaction wheels. An overall system mass savings can be realized if these two subsystems are combined using multiple flywheels for simultaneous kinetic energy storage and momentum transfer. Several authors have studied the control of the flywheels to accomplish this and have published simulation results showing the feasibility and performance. This paper presents the first experimental results showing combined energy storage and momentum control about a single axis using two flywheels.
Effects of Biggest Loser exercise depictions on exercise-related attitudes.
Berry, Tanya R; McLeod, Nicole C; Pankratow, Melanie; Walker, Jessica
2013-01-01
To examine whether participants who watched an exercise-related segment of The Biggest Loser television program would have different explicit and implicit affective exercise-related attitudes than those of control participants. University students (N=138) watched a clip of The Biggest Loser or American Idol, then completed a Go/No-go Association Task, a thought-listing task, and questionnaires measuring explicit attitudes, activity level, and mood. Participants who watched The Biggest Loser had significantly lower explicit, but not implicit, attitudes towards exercise than did control participants. There is a need to examine the influence of popular media depictions of exercise.
Autonomous control system reconfiguration for spacecraft with non-redundant actuators
NASA Astrophysics Data System (ADS)
Grossman, Walter
1995-05-01
The Small Satellite Technology Initiative (SSTI) 'CLARK' spacecraft is required to be single-failure tolerant, i.e., no failure of any single component or subsystem shall result in complete mission loss. Fault tolerance is usually achieved by implementing redundant subsystems. Fault tolerant systems are therefore heavier and cost more to build and launch than non-redundent, non fault-tolerant spacecraft. The SSTI CLARK satellite Attitude Determination and Control System (ADACS) achieves single-fault tolerance without redundancy. The attitude determination system system uses a Kalman Filter which is inherently robust to loss of any single attitude sensor. The attitude control system uses three orthogonal reaction wheels for attitude control and three magnetic dipoles for momentum control. The nominal six-actuator control system functions by projecting the attitude correction torque onto the reaction wheels while a slower momentum management outer loop removes the excess momentum in the direction normal to the local B field. The actuators are not redundant so the nominal control law cannot be implemented in the event of a loss of a single actuator (dipole or reaction wheel). The spacecraft dynamical state (attitude, angular rate, and momentum) is controllable from any five-element subset of the six actuators. With loss of an actuator the instantaneous control authority may not span R(3) but the controllability gramian integral(limits between t,0) Phi(t, tau)B(tau )B(prime)(tau) Phi(prime)(t, tau)d tau retains full rank. Upon detection of an actuator failure the control torque is decomposed onto the remaining active axes. The attitude control torque is effected and the over-orbit momentum is controlled. The resulting control system performance approaches that of the nominal system.
Straker, Leon M; Smith, Kyla L; Fenner, Ashley A; Kerr, Deborah A; McManus, Alexandra; Davis, Melissa C; Fielding, Angela M; Olds, Tim S; Hagger, Martin S; Smith, Anne J; Abbott, Rebecca A
2012-06-21
Current estimates place just under one quarter of adolescents in Australia as overweight or obese. Adolescence has been identified as a critical period for the development of obesity, yet despite this recognition, there is limited systematic research into or evaluation of interventions for overweight adolescents. Reviews have concluded that there is a substantive evidence gap for effective intervention, but physical activity, lifestyle change and family involvement have been identified as promising foci for treatment. This paper reports on the development of a staggered-entry, waitlist controlled clinical trial to assess the impact of a multidisciplinary intervention aiming to change the poor health trajectory of overweight adolescents and help them avoid morbid obesity in adulthood-Curtin University's Activity, Food and Attitudes Program (CAFAP). 96 adolescents, aged 11-16 years, and parents, will attend twice weekly during an 8 week intensive multidisciplinary program with maintenance follow-up focussed on improving activity, food and attitude habits. Follow-up assessments will be conducted immediately after completing the intensive program, and at 3, 6 and 12 months post intensive program. Main outcomes will be objectively-measured physical activity, sedentary behaviour and activity behaviours; food intake (measured by 3 day diary) and food behaviours; body composition, fitness and physical function; mental and social well-being (quality of life, mood and attitudes), and family functioning. This trial will provide important information to understand whether a community based multidisciplinary intervention can have short and medium term effects on activity and food habits, attitudes, and physical and mental health status of overweight adolescents. Australian New Zealand Clinical Trials Registry ACTRN12611001187932.
Glapa, Agata; Grzesiak, Joanna; Laudanska-Krzeminska, Ida; Chin, Ming-Kai; Edginton, Christopher R; Mok, Magdalena Mo Ching; Bronikowski, Michal
2018-02-21
The purpose of this study was to examine the effectiveness of the Brain Breaks® Physical Activity Solutions in changing attitudes toward physical activity of school children in a community in Poland. In 2015, a sample of 326 pupils aged 9-11 years old from 19 classes at three selected primary schools were randomly assigned to control and experimental groups within the study. During the classes, children in the experimental group performed physical activities two times per day in three to five minutes using Brain Breaks® videos for four months, while the control group did not use the videos during the test period. Students' attitudes toward physical activities were assessed before and after the intervention using the "Attitudes toward Physical Activity Scale". Repeated measures of ANOVA were used to examine the change from pre- to post-intervention. Overall, a repeated measures ANOVA indicated time-by-group interaction effects in 'Self-efficacy on learning with video exercises', F(1.32) = 75.28, p = 0.00, η2 = 0.19. Although the changes are minor, there were benefits of the intervention. It may be concluded that HOPSports Brain Breaks® Physical Activity Program contributes to better self-efficacy on learning while using video exercise of primary school children.
Modelling and simulation of Space Station Freedom berthing dynamics and control
NASA Technical Reports Server (NTRS)
Cooper, Paul A.; Garrison, James L., Jr.; Montgomery, Raymond C.; Wu, Shih-Chin; Stockwell, Alan E.; Demeo, Martha E.
1994-01-01
A large-angle, flexible, multibody, dynamic modeling capability has been developed to help validate numerical simulations of the dynamic motion and control forces which occur during berthing of Space Station Freedom to the Shuttle Orbiter in the early assembly flights. This paper outlines the dynamics and control of the station, the attached Shuttle Remote Manipulator System, and the orbiter. The simulation tool developed for the analysis is described and the results of two simulations are presented. The first is a simulated maneuver from a gravity-gradient attitude to a torque equilibrium attitude using the station reaction control jets. The second simulation is the berthing of the station to the orbiter with the station control moment gyros actively maintaining an estimated torque equilibrium attitude. The influence of the elastic dynamic behavior of the station and of the Remote Manipulator System on the attitude control of the station/orbiter system during each maneuver was investigated. The flexibility of the station and the arm were found to have only a minor influence on the attitude control of the system during the maneuvers.
NASA Astrophysics Data System (ADS)
Kikuchi, Shota; Howell, Kathleen C.; Tsuda, Yuichi; Kawaguchi, Jun'ichiro
2017-11-01
The motion of a spacecraft in proximity to a small body is significantly perturbed due to its irregular gravity field and solar radiation pressure. In such a strongly perturbed environment, the coupling effect of the orbital and attitude motions exerts a large influence that cannot be neglected. However, natural orbit-attitude coupled dynamics around small bodies that are stationary in both orbital and attitude motions have yet to be observed. The present study therefore investigates natural coupled motion that involves both a Sun-synchronous orbit and Sun-tracking attitude motion. This orbit-attitude coupled motion enables a spacecraft to maintain its orbital geometry and attitude state with respect to the Sun without requiring active control. Therefore, the proposed method can reduce the use of an orbit and attitude control system. This paper first presents analytical conditions to achieve Sun-synchronous orbits and Sun-tracking attitude motion. These analytical solutions are then numerically propagated based on non-linear coupled orbit-attitude equations of motion. Consequently, the possibility of implementing Sun-synchronous orbits with Sun-tracking attitude motion is demonstrated.
Kerner, Matthew S
2005-06-01
Using the theory of planned behavior as a conceptual framework, scales assessing Attitude to Leisure-time Physical Activity, Expectations of Others, Perceived Control, and Intention to Engage in Leisure-time Physical Activity were developed for use among middle-school students. The study sample included 349 boys and 400 girls, 10 to 14 years of age (M=11.9 yr., SD=.9). Unipolar and bipolar scales with seven response choices were developed, with each scale item phrased in a Likert-type format. Following revisions, 22 items were retained in the Attitude to Leisure-time Physical Activity Scale, 10 items in the Expectations of Others Scale, 3 items in the Perceived Control Scale, and 17 items in the Intention to Engage in Leisure-time Physical Activity Scale. Adequate internal consistency was indicated by standardized coefficients alpha ranging from .75 to .89. Current results must be extended to assess discriminant and predictive validities and to check various reliabilities with new samples, then evaluation of intervention techniques for promotion of positive attitudes about leisure-time physical activity, including perception of control and intentions to engage in leisure-time physical activity.
Guelfi, Kym J; Wang, Chen; Dimmock, James A; Jackson, Ben; Newnham, John P; Yang, Huixia
2015-12-22
Despite the well-established benefits of exercise during pregnancy, many women remain inactive. This may be related, in part, to women's beliefs about exercise in pregnancy, which are likely influenced by cultural background. Accordingly, the aim of this study was to compare attitudes, subjective norms, and perceived behavioural control toward exercise, together with current levels of exercise participation between Chinese and Australian women during pregnancy. A second aim was to determine the extent to which these factors predict intention to exercise within a Theory of Planned Behaviour framework. Pregnant women (22 ± 2 weeks of gestation) living in China (n = 240) and Australia (n = 215) completed a questionnaire designed to assess a) maternal beliefs regarding the importance of exercise in relation to other health behaviours, b) attitudes, subjective norms, perceived behavioural control and intentions toward exercise, and c) current levels of physical activity. One-way analyses of variance were used to compare the demographics, maternal beliefs, attitudes, subjective norms, perceived behavioural control, intentions to exercise, and current physical activity levels between the Chinese and Australian samples. Structural equation modelling was used to determine which factors predicted intention to exercise in the two samples. Australian women reported higher levels of current exercise and intentions to exercise in the next four weeks of pregnancy compared with Chinese women. These observations were associated with higher instrumental attitudes, ratings of subjective norm, and perceived behavioural control toward exercise in the Australian women. Instrumental attitudes and perceived behavioural control predicted intention to exercise in the Australian women, while perceived behavioural control was the only predictor of intentions to exercise in the Chinese sample. Beliefs, attitudes, barriers and intentions towards exercise during pregnancy differ between cultures. Understanding these differences may assist in the design of exercise interventions to maximise exercise adherence and lifelong physical activity patterns.
Attitude control system for a lightweight flapping wing MAV.
Tijmons, Sjoerd; Karásek, Matěj; de Croon, G C H E
2018-03-14
Robust attitude control is an essential aspect of research on autonomous flight of flapping wing Micro Air Vehicles. The mechanical solutions by which the necessary control moments are realised come at the price of extra weight and possible loss of aerodynamic efficiency. Stable flight of these vehicles has been shown by several designs using a conventional tail, but also by tailless designs that use active control of the wings. In this study a control mechanism is proposed that provides active control over the wings. The mechanism improves vehicle stability and agility by generation of control moments for roll, pitch and yaw. Its effectiveness is demonstrated by static measurements around all the three axes. Flight test results confirm that the attitude of the test vehicle, including a tail, can be successfully controlled in slow forward flight conditions. Furthermore, the flight envelope is extended with robust hovering and the ability to reverse the flight direction using a small turn space. This capability is very important for autonomous flight capabilities such as obstacle avoidance. Finally, it is demonstrated that the proposed control mechanism allows for tailless hovering flight. © 2018 IOP Publishing Ltd.
Mirkarimi, Kamal; Eri, Maryam; Ghanbari, Mohammad R; Kabir, Mohammad J; Raeisi, Mojtaba; Ozouni-Davaji, Rahman B; Aryaie, Mohammad; Charkazi, Abdurrahman
2017-10-30
We were guided by the Protection Motivation Theory to test the motivational interviewing effects on attitude and intention of obese and overweight women to do regular physical activity. In a randomized controlled trial, we selected using convenience sampling 60 overweight and obese women attending health centres. The women were allocated to 2 groups of 30 receiving a standard weight-control programme or motivational interviewing. All constructs of the theory (perceived susceptibility, severity, self-efficacy and response efficacy) and all anthropometric characteristics (except body mass index) were significantly different between the groups at 3 study times. The strongest predictors of intention to do regular physical exercise were perceived response efficacy and attitude at 2- and 6-months follow-up. We showed that targeting motivational interviewing with an emphasis on Protection Motivation Theory constructs appeared to be beneficial for designing and developing appropriate intervention to improve physical activity status among women with overweight and obesity.
NASA Astrophysics Data System (ADS)
Iai, Masafumi; Durali, Mohammad; Hatsuzawa, Takeshi
Recent research has been extending the applications of small satellites called microsatellites, nanosatellites, or picosatellites. To further improve capability of those satellites, a lightweight, active attitude-control mechanism is needed. This paper proposes a concept of inertial orientation control, an attitude control method using movable solar arrays. This method is made suitable for nanosatellites by the use of shape memory alloy (SMA)-actuated elastic hinges and a simple maneuver generation algorithm. The combination of SMA and an elastic hinge allows the hinge to remain lightweight and free of frictional or rolling contacts. Changes in the shrinking and stretching speeds of the SMA were measured in a vacuum chamber. The proposed algorithm constructs a maneuver to achieve arbitrary attitude change by repeating simple maneuvers called unit maneuvers. Provided with three types of unit maneuvers, each degree of freedom of the satellite can be controlled independently. Such construction requires only simple calculations, making it a practical algorithm for a nanosatellite with limited computational capability. In addition, power generation variation caused by maneuvers was analyzed to confirm that a maneuver from any initial attitude to an attitude facing the sun was justifiable in terms of the power budget.
Navidian, Ali; Rigi, Shahindokht Navabi; Soltani, Parvin
2016-01-01
Background Marital relationships may fluctuate due to physical and psychological changes during pregnancy. This study aimed to investigate the effect of group sexual counseling on the traditional perceptions and attitudes of pregnant women. Methods This was a quasiexperimental intervention study. Among the pregnant women who were referred to health care centers in Zahedan, Iran, in 2015 for routine care during pregnancy, 100 individuals were chosen and randomly categorized into two groups: intervention (n=50) and control (n=50). Variables were the participant’s attitudes and beliefs on sexual activity during pregnancy. The data were collected during pregnancy using the Sexual Activities and Attitudes Questionnaire. The questionnaire was completed before and 6 weeks after five sessions of group sexual counseling. Data were analyzed using SPSS software (Version 20) with descriptive and analytical statistics. Results The mean of score changes for sexual attitudes and traditional perceptions in the intervention group was significantly higher than that in the control group (P<0.0001). Analysis of covariance also showed that the mean score of the participant’s traditional perceptions and sexual attitudes in both groups was significantly different after the group sexual counseling. Discussion Due to the positive effect of group sexual counseling on improving the attitudes of pregnant women about sexual issues and reframing the traditional perceptions over sexual activities during pregnancy, it is recommended that this educational intervention should be integrated into counseling and prenatal care for pregnant women. PMID:27366105
Research findings can change attitudes about corporal punishment.
Holden, George W; Brown, Alan S; Baldwin, Austin S; Croft Caderao, Kathryn
2014-05-01
Positive attitudes toward the use of corporal punishment (CP) predict subsequent spanking behavior. Given that CP has frequently been associated with behavior problems in children and child maltreatment, this prevention work was designed to test whether adults' attitudes could be changed by informing participants about the research findings on problematic behaviors associated with CP. Two random assignment studies are reported. In Study 1, we tested whether an active reading condition would result in more attitude change than a passive condition. With a sample of 118 non-parent adults, we found that after reading very brief research summaries on the problems associated with CP, there was a significant decrease in favorable attitudes toward CP. Contrary to expectations, the magnitude of the change was comparable for active and passive processing conditions. In Study 2, we extended our approach to a sample of 520 parents and included a control group. A significant decrease in positive attitudes toward spanking was observed in the intervention group, but no change for the control group. Parents who were unaware of the research showed more change after reading the summaries. Thus, these studies demonstrate that a brief and cost-effective approach to raise awareness of research findings can reduce positive attitudes toward CP. Implications for prevention and intervention are discussed. Copyright © 2013. Published by Elsevier Ltd.
ERIC Educational Resources Information Center
Johnson, Ray, Jr.; Simon, Elizabeth J.; Henkell, Heather; Zhu, John
2011-01-01
Event-related potentials (ERPs) are unique in their ability to provide information about the timing of activity in the neural networks that perform complex cognitive processes. Given the dearth of extant data from normal controls on the question of whether attitude representations are stored in episodic or semantic memory, the goal here was to…
ADRC for spacecraft attitude and position synchronization in libration point orbits
NASA Astrophysics Data System (ADS)
Gao, Chen; Yuan, Jianping; Zhao, Yakun
2018-04-01
This paper addresses the problem of spacecraft attitude and position synchronization in libration point orbits between a leader and a follower. Using dual quaternion, the dimensionless relative coupled dynamical model is derived considering computation efficiency and accuracy. Then a model-independent dimensionless cascade pose-feedback active disturbance rejection controller is designed to spacecraft attitude and position tracking control problems considering parameter uncertainties and external disturbances. Numerical simulations for the final approach phase in spacecraft rendezvous and docking and formation flying are done, and the results show high-precision tracking errors and satisfactory convergent rates under bounded control torque and force which validate the proposed approach.
The Effects of 5E Inquiry Learning Activities on Achievement and Attitude toward Chemistry
ERIC Educational Resources Information Center
Sen, Senol; Oskay, Ozge Ozyalcin
2017-01-01
The purpose of this study was to investigate the effects of 5E inquiry learning activities on students' achievement, attitude toward chemistry. A non-equivalent control group design was used to the quasi-experimental research in this study. A total of 34 (8 males and 26 females) undergraduates in Turkey voluntarily participated in the study. The…
ERIC Educational Resources Information Center
Korkmaz, Özgen
2016-01-01
The purpose of the present research is to designate the effects of Scratch-based game activities on students' attitudes towards learning computer programming, self-efficacy beliefs and levels of academic achievement. The research was conducted through a pre-test-post-test control group quasi-experimental study. The study group consists of 49…
ERIC Educational Resources Information Center
Esslinger, Keri A.; Grimes, Amanda R.; Pyle, Elizabeth
2016-01-01
In this study, we investigated students' attitudes toward physical activity (PA) when including a required PA component in a university-required personal wellness class. The study included (a) an experimental group of students enrolled in a personal wellness course in which there was a required PA requirement and (b) a control group of students…
Molina, Antonio J; Fernández, Tania; Fernández, Daniel; Delgado, Miguel; de Abajo, Serafín; Martín, Vicente
2012-11-01
To examine the effectiveness of a tobacco control course on the improvement of knowledge, attitudes and beliefs about smoking among health sciences' students. This was a quasi-experimental study of community intervention carried out during the years 2005-2008, at 2 university health science centres in northwest Spain. A total of 290 students on the intervention and 256 on the control campus took part in the study. The intervention consisted of a course on the prevention and control of tobacco use offered only on the intervention campus. Data were collected before the intervention and 6 months afterwards. After the course, significant differences between groups were observed in the improvement of knowledge, attitudes and perceived ability to act in tobacco control. The introduction of training concerning smoking through active methodologies had a positive impact on the knowledge, attitudes and beliefs about tobacco of students. Copyright © 2011 Elsevier Ltd. All rights reserved.
Skylab thruster attitude control system
NASA Technical Reports Server (NTRS)
Wilmer, G. E., Jr.
1974-01-01
Preflight activities and the Skylab mission support effort for the thruster attitude control system (TACS) are documented. The preflight activities include a description of problems and their solutions encountered in the development, qualification, and flight checkout test programs. Mission support effort is presented as it relates to system performance assessment, real-time problem solving, flight anomalies, and the daily system evaluation. Finally, the detailed flight evaluation is presented for each phase of the mission using system telemetry data. Data assert that the TACS met or exceeded design requirements and fulfilled its assigned mission objectives.
2012-01-01
Background Current estimates place just under one quarter of adolescents in Australia as overweight or obese. Adolescence has been identified as a critical period for the development of obesity, yet despite this recognition, there is limited systematic research into or evaluation of interventions for overweight adolescents. Reviews have concluded that there is a substantive evidence gap for effective intervention, but physical activity, lifestyle change and family involvement have been identified as promising foci for treatment. Methods This paper reports on the development of a staggered-entry, waitlist controlled clinical trial to assess the impact of a multidisciplinary intervention aiming to change the poor health trajectory of overweight adolescents and help them avoid morbid obesity in adulthood—Curtin University’s Activity, Food and Attitudes Program (CAFAP). 96 adolescents, aged 11–16 years, and parents, will attend twice weekly during an 8 week intensive multidisciplinary program with maintenance follow-up focussed on improving activity, food and attitude habits. Follow-up assessments will be conducted immediately after completing the intensive program, and at 3, 6 and 12 months post intensive program. Main outcomes will be objectively-measured physical activity, sedentary behaviour and activity behaviours; food intake (measured by 3 day diary) and food behaviours; body composition, fitness and physical function; mental and social well-being (quality of life, mood and attitudes), and family functioning. Discussion This trial will provide important information to understand whether a community based multidisciplinary intervention can have short and medium term effects on activity and food habits, attitudes, and physical and mental health status of overweight adolescents. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12611001187932. PMID:22721261
Laforest, Sophie; Lorthios-Guilledroit, Agathe; Nour, Kareen; Parisien, Manon; Fournier, Michel; Ellemberg, Dave; Guay, Danielle; Desgagn�s-Cyr, Charles-�mile; Bier, Nathalie
2017-01-01
Abstract This study examined the effects on attitudes and lifestyle behavior of Jog your Mind, a multi-factorial community-based program promoting cognitive vitality among seniors with no known cognitive impairment. A quasi-experimental study was conducted. Twenty-three community organizations were assigned either to the experimental group (offering the program) or to the control group (creating a waiting list). They recruited 294 community-dwelling seniors. The aims of the study were to verify the effects of the program on attitudes and behaviors related to cognitive vitality and to explore its effects on cognitive vitality. Data was collected at baseline and after the program. Regression analyses revealed that, following their participation in the program, experimental group participants reported: (i) in terms of attitudes, having a greater feeling of control concerning their cognitive capacities, (ii) in terms of behaviors, using significantly more memory strategies and practicing more physical activity and stimulating activities than control group participants. However, the program had no significant effects on measures of cognitive vitality. This study supports the fact that a multi-factorial community-based program can have significant effects on seniors’ attitudes and lifestyle behaviors related to cognitive vitality but at short term, no effects on cognitive vitality it-self were found. PMID:28334988
Peterson, Jamie Lee; Puhl, Rebecca M; Luedicke, Joerg
2012-09-01
At school, physical education (PE) teachers and coaches may be key supports for physical activity. Unfortunately, PE teachers may endorse negative stereotypes and attitudes toward overweight youth. These biases may influence the amount of instruction physical educators provide to students and their participation in PE or other physical activity. This study assessed physical educators' (N = 162) ability and performance expectations, attributions, and attitudes toward overweight and non-overweight students. Physical educators endorsed inferior ability expectations for overweight students compared to non-overweight students. Poorer performance expectations were limited to overweight female targets, but when controlling for participant characteristics, this effect became marginally significant for overweight male targets. There was a trend such that participants endorsed more external attributions for the abilities and performance of overweight female students, yet this effect was reduced to marginal significance when controlling for participant characteristics. Participants endorsed more negative attitudes for both overweight males and females compared to non-overweight youth. Findings indicate that physical educators' expectations, attributions, and attitudes regarding students may be negatively influenced by youth body weight, and differ by student gender. The potential effect of physical educators' weight bias on adolescent participation in physical activity and its implications for students' physical health, academic achievement, and social development are discussed. © 2012, American School Health Association.
Dynamic modeling and ascent flight control of Ares-I Crew Launch Vehicle
NASA Astrophysics Data System (ADS)
Du, Wei
This research focuses on dynamic modeling and ascent flight control of large flexible launch vehicles such as the Ares-I Crew Launch Vehicle (CLV). A complete set of six-degrees-of-freedom dynamic models of the Ares-I, incorporating its propulsion, aerodynamics, guidance and control, and structural flexibility, is developed. NASA's Ares-I reference model and the SAVANT Simulink-based program are utilized to develop a Matlab-based simulation and linearization tool for an independent validation of the performance and stability of the ascent flight control system of large flexible launch vehicles. A linearized state-space model as well as a non-minimum-phase transfer function model (which is typical for flexible vehicles with non-collocated actuators and sensors) are validated for ascent flight control design and analysis. This research also investigates fundamental principles of flight control analysis and design for launch vehicles, in particular the classical "drift-minimum" and "load-minimum" control principles. It is shown that an additional feedback of angle-of-attack can significantly improve overall performance and stability, especially in the presence of unexpected large wind disturbances. For a typical "non-collocated actuator and sensor" control problem for large flexible launch vehicles, non-minimum-phase filtering of "unstably interacting" bending modes is also shown to be effective. The uncertainty model of a flexible launch vehicle is derived. The robust stability of an ascent flight control system design, which directly controls the inertial attitude-error quaternion and also employs the non-minimum-phase filters, is verified by the framework of structured singular value (mu) analysis. Furthermore, nonlinear coupled dynamic simulation results are presented for a reference model of the Ares-I CLV as another validation of the feasibility of the ascent flight control system design. Another important issue for a single main engine launch vehicle is stability under mal-function of the roll control system. The roll motion of the Ares-I Crew Launch Vehicle under nominal flight conditions is actively stabilized by its roll control system employing thrusters. This dissertation describes the ascent flight control design problem of Ares-I in the event of disabled or failed roll control. A simple pitch/yaw control logic is developed for such a technically challenging problem by exploiting the inherent versatility of a quaternion-based attitude control system. The proposed scheme requires only the desired inertial attitude quaternion to be re-computed using the actual uncontrolled roll angle information to achieve an ascent flight trajectory identical to the nominal flight case with active roll control. Another approach that utilizes a simple adjustment of the proportional-derivative gains of the quaternion-based flight control system without active roll control is also presented. This approach doesn't require the re-computation of desired inertial attitude quaternion. A linear stability criterion is developed for proper adjustments of attitude and rate gains. The linear stability analysis results are validated by nonlinear simulations of the ascent flight phase. However, the first approach, requiring a simple modification of the desired attitude quaternion, is recommended for the Ares-I as well as other launch vehicles in the event of no active roll control. Finally, the method derived to stabilize a large flexible launch vehicle in the event of uncontrolled roll drift is generalized as a modified attitude quaternion feedback law. It is used to stabilize an axisymmetric rigid body by two independent control torques.
Student construction of small molecule models using Spartan Model to explore polarity
NASA Astrophysics Data System (ADS)
Dale, Glenn Lamar
2006-12-01
This study compared the attitudes and the gains of knowledge concerning Lewis structures and polarity of molecules. The students performed a lab exercise in which they drew Lewis structures, constructed models of the molecules, determined the geometry of the molecules, and determined the polarity of the molecules. The control group students constructed models using physical ball-and-stick models. The treatment group students used Spartan Model to construct models. Students from a university and a community college participated in this study. Four lab classes at each school made up the treatment group. Five lab classes at the university and three lab classes at the community college made up the control group. The treatment group classes were selected based on available computer resources. All students in the study were given the Lab Pre Test, Lab Post Test, and the Lecture Post Test to assess the student's ability to answer questions pertaining to Lewis structures and polarity of molecules. An Attitudinal Survey assessed the attitudes of the students who participated in the study. Student interviews were performed to assess the student's attitudes towards the lab exercise. The interviews investigated attitudes about the modeling exercise, Lewis structures, and polarity of molecules. There were no significant differences in the performance of the treatment group when compared to the control group on the performance assessment instruments at the university or the community college. The treatment group students at the university had a more positive attitude about the lab activity. They believed that the lab activity helped them better understand the concepts of Lewis structure and molecular polarity. At the community college, the control group students had a more positive attitude about the lab activity. The students involved in the study believed that the lab activity helped them to understand the concepts of molecular geometry and polarity. The interviews of the treatment group students indicated that they strongly believed that the lab activity helped them better understand the concept of Lewis structures and of molecular polarity. As reflected in the interviews of the treatment group and the control group, the lab activity did not help the students be able to look at a Lewis structure and build a mental image of the molecule. The students believed the electrostatic potential plots generated by Spartan Model were very insightful into the concept of polarity. It gave them a visual representation of a difficult topic.
Neural activity predicts attitude change in cognitive dissonance.
van Veen, Vincent; Krug, Marie K; Schooler, Jonathan W; Carter, Cameron S
2009-11-01
When our actions conflict with our prior attitudes, we often change our attitudes to be more consistent with our actions. This phenomenon, known as cognitive dissonance, is considered to be one of the most influential theories in psychology. However, the neural basis of this phenomenon is unknown. Using a Solomon four-group design, we scanned participants with functional MRI while they argued that the uncomfortable scanner environment was nevertheless a pleasant experience. We found that cognitive dissonance engaged the dorsal anterior cingulate cortex and anterior insula; furthermore, we found that the activation of these regions tightly predicted participants' subsequent attitude change. These effects were not observed in a control group. Our findings elucidate the neural representation of cognitive dissonance, and support the role of the anterior cingulate cortex in detecting cognitive conflict and the neural prediction of attitude change.
Attitudinal Effects of a Student-Centered Active Learning Environment
NASA Astrophysics Data System (ADS)
Oliver-Hoyo, Maria T.; Allen, Deedee
2005-06-01
The importance of attitudes toward science has risen from widely accepted assumptions that achievement and attitude are positively interdependent and that affective variables are as important as cognitive variables in molding student learning. This report examines the effect on student attitudes toward learning chemistry in an active learning environment that has incorporated elements believed to positively influence student attitudes toward science including cooperative learning, hands-on activities, real-world applications, and engaging technology. These elements were considered for synergetic effects and not as individual contributors to the overall results. Two different sections of the same general chemistry course participated. The lecture setting was used as the control. Residualized gain scores were used to compare net changes in student attitudes. Data were analyzed for possible differences in gain for different academic majors. Anxiety in chemistry was monitored for the two class settings in three areas, learning in chemistry, chemistry evaluation, and chemical handling. Qualitative student feedback was also collected and is summarized in this report on the attitudinal aspects of instruction.
NASA Technical Reports Server (NTRS)
Jani, Yashvant
1992-01-01
As part of the RICIS activity, the reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Max satellite simulation. This activity is carried out in the software technology laboratory utilizing the Orbital Operations Simulator (OOS). This report is deliverable D2 Altitude Control Results and provides the status of the project after four months of activities and outlines the future plans. In section 2 we describe the Fuzzy-Learner system for the attitude control functions. In section 3, we provide the description of test cases and results in a chronological order. In section 4, we have summarized our results and conclusions. Our future plans and recommendations are provided in section 5.
Distributed control of large space structures
NASA Technical Reports Server (NTRS)
Schaechter, D. B.
1981-01-01
Theoretical developments and the results of laboratory experiments are treated as they apply to active attitude and vibration control, as well as static shape control. Modern control theory was employed throughout as the method for obtaining estimation and control laws.
NASA Technical Reports Server (NTRS)
Quast, Peter; Tung, Frank; West, Mark; Wider, John
2000-01-01
The Chandra X-ray Observatory (CXO, formerly AXAF) is the third of the four NASA great observatories. It was launched from Kennedy Space Flight Center on 23 July 1999 aboard the Space Shuttle Columbia and was successfully inserted in a 330 x 72,000 km orbit by the Inertial Upper Stage (IUS). Through a series of five Integral Propulsion System burns, CXO was placed in a 10,000 x 139,000 km orbit. After initial on-orbit checkout, Chandra's first light images were unveiled to the public on 26 August, 1999. The CXO Pointing Control and Aspect Determination (PCAD) subsystem is designed to perform attitude control and determination functions in support of transfer orbit operations and on-orbit science mission. After a brief description of the PCAD subsystem, the paper highlights the PCAD activities during the transfer orbit and initial on-orbit operations. These activities include: CXO/IUS separation, attitude and gyro bias estimation with earth sensor and sun sensor, attitude control and disturbance torque estimation for delta-v burns, momentum build-up due to gravity gradient and solar pressure, momentum unloading with thrusters, attitude initialization with star measurements, gyro alignment calibration, maneuvering and transition to normal pointing, and PCAD pointing and stability performance.
Mexican-American Adolescent Sexuality and Sexual Knowledge: An Exploratory Study.
ERIC Educational Resources Information Center
Padilla, Amado M.; Baird, Traci L.
1991-01-01
Examines sexual knowledge, attitudes and practices of 84 Mexican-American adolescents. Findings show low sexual knowledge for all subgroups. Few sexually active subjects practiced contraception. Majority indicated birth control makes sex seem preplanned. Respondents appeared traditional in sex attitudes, with virginity and birth-control…
Using Science Activities To Internalize Locus of Control. Final Report.
ERIC Educational Resources Information Center
Rowland, Paul McD.
This project was designed to investigate the effect of the use of cause-and-effect activities in the science curriculum on the locus of control of the learner. The purpose of this research is to find the effect of the activities on the learner's locus of control and attitude toward science at grades 7 through 10. A multivariate analysis of…
Attitude orientation control for a spinning satellite
NASA Astrophysics Data System (ADS)
Frost, Gerald
The Department of the Air Force, Headquarters Space Systems Division, and the National Aeronautics and Space Administration (NASA) are currently involved in litigation with Hughes Aircraft Company over the alledged infringement of the 'Williams patent,' which describes a method for attitude control of a spin-stabilized vehicle. Summarized here is pre-1960 RAND work on this subject and information obtained from RAND personnel knowledgeable on this subject. It was concluded that there is no RAND documentation that directly parallels the 'Williams patent' concept. Also, the TIROS II magnetic torque attitude control method is reviewed. The TIROS II meteorological satellite, launched on November 23, 1960, incorporated a magnetic actuation system for spin axis orientation control. The activation system was ground controlled to orient the satellite spin axis to obtain the desired pointing direction for optical and infrared sensor subsystems.
Jahanfar, S; Lye, M S; Rampal, L
2009-02-01
The aim of this study was to investigate the knowledge, attitudes and behaviour of university students regarding acquired immunodeficiency syndrome (AIDS) and the human immunodeficiency virus (HIV). A randomised controlled trial of 530 university students was done using peer-adult facilitators. Participants completed a questionnaire before and after the intervention, which was a four-hour group session. A prevention programme was developed by local experts, health educators and peer facilitators. The peer-adult-led programme was designed to provide a conceptual model of HIV risk reduction through information, motivational and behavioural skills, a harm reduction module and health promotion theme. The main outcome measured was the level of knowledge, attitudes and behaviour scores. The results suggest that relative to the control group, participants in the intervention group had higher levels of knowledge (30.37 vs. 25.40; p-value is 0.001) and a better attitude (12.27 vs. 10.84; p-value is 0.001). However, there was no difference in the behavioural score (9.47 vs. 9.41; p-value is 0.530). The correlation between the level of knowledge and age and the level of education was found in the intervention group, but not in the control group (p-value is 0.01). Attitude and gender were found to be correlated in the intervention group only (p-value is 0.01). Our programme was successful in increasing knowledge and improving attitudes towards AIDS and HIV. However, it did not improve risk-taking behaviour. Peer-adult-led educational programmes for youth using various interactional activities, such as small group discussions, poster activity and empathy exercises, can be successful in changing the prevailing youth perceptions of AIDS and HIV.
Investigating Attitudes toward Physical Education: Validation across Two Instruments
ERIC Educational Resources Information Center
Donovan, Corinne Baron; Mercier, Kevin; Phillips, Sharon R.
2015-01-01
The Centers for Disease Control have suggested that physical education plays a role in promoting healthy lifestyles. Prior research suggests a link between attitudes toward physical education and physical activity outside school. The current study provides additional evidence of construct validity through a validation across two instruments…
Attitudes Toward Physical Activity of Champion Women Basketball Players.
ERIC Educational Resources Information Center
Corbin, Charles B.
This study was undertaken to determine which attitudes were central to the motivation of women involved in championship basketball competition. Seventy-five women members of teams represented in national basketball championships served as subjects for this experiment. In addition, a control group of 212 women was randomly selected from physical…
A New Approach to Attitude Stability and Control for Low Airspeed Vehicles
NASA Technical Reports Server (NTRS)
Lim, K. B.; Shin, Y-Y.; Moerder, D. D.; Cooper, E. G.
2004-01-01
This paper describes an approach for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The large thrust vector that characterizes such vehicles can be modulated to provide control forces and moments to the airframe, but such modulation is accompanied by significant unsteady flow effects. These effects are difficult to model, and can compromise the practical value of thrust vectoring in closed-loop attitude stability, even if the thrust vectoring machinery has sufficient bandwidth for stabilization. The stabilization approach described in this paper is based on using internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other "outer loop" control functions. The three main components of this approach are: (1) a z-body axis angular momentum bias enhances static attitude stability, reducing the amount of control activity needed for stabilization, (2) optionally, gimbaled reaction wheels provide high-bandwidth control torques for additional stabilization, or agility, and (3) the resulting strongly coupled system dynamics are controlled by a multivariable controller. A flight test vehicle is described, and nonlinear simulation results are provided that demonstrate the efficiency of the approach.
Kerner, Matthew S; Kurrant, Anthony B
2003-12-01
This study was designed to test the efficacy of the theory of planned behavior in predicting intention to engage in leisure-time physical activity and leisure-time physical activity behavior of high school girls. Rating scales were used for assessing attitude to leisure-time physical activity, subjective norm, perceived control, and intention to engage in leisure-time physical activity among 129 ninth through twelfth graders. Leisure-time physical activity was obtained from 3-wk. diaries. The first hierarchical multiple regression indicated that perceived control added (R2 change = .033) to the contributions of attitude to leisure-time physical activity and subjective norm in accounting for 50.7% of the total variance of intention to engage in leisure-time physical activity. The second regression analysis indicated that almost 10% of the variance of leisure-time physical activity was explicated by intention to engage in leisure-time physical activity and perceived control, with perceived control contributing 6.4%. From both academic and theoretical standpoints, our findings support the theory of planned behavior, although quantitatively the variance of leisure-time physical activity was not well-accounted for. In addition, considering the small percentage increase in variance explained by the addition of perceived control explaining variance of intention to engage in leisure-time physical activity, the pragmatism of implementing the measure of perceived control is questionable for this population.
Onion, C W; Bartzokas, C A
1998-04-01
When attempting to implement evidence-based medicine, such as through clinical guidelines, we often rely on passive educational tactics, for example didactic lectures and bulletins. These methods involve the recipient in relatively superficial processing of information, and any consequent attitude changes can be expected to be short-lived. However, active methods, such as practice-based discussion, should involve recipients in deep processing, with more enduring attitude changes. In this experiment, the aim was to assess the efficacy of an active strategy at promoting deep processing and its effectiveness, relative to a typical passive method, at changing attitudes between groups of GPs over 12 months across an English Health District. All 191 GPs operating from 69 practices in the Wirral Health District of Northwest England were assigned, with minimization of known confounding variables, to three experimental groups: active, passive and control. The groups were shown to have similar learning styles. The objective of the study was to impart knowledge of best management of infections as captured in a series of locally developed clinical guidelines. The passive group GPs were given a copy of the guidelines and were invited to an hour-long lecture event. The GPs in the deep group were given a copy of the guidelines and were invited to engage in an hour-long discussion about the guideline content at their own premises. The control group received neither the guidelines nor any educational contact regarding them. Three months before and 12 months after the interventions, all GPs were sent a postal questionnaire on their preferred empirical antibiotic for 10 common bacterial infections. The responses were compared in order to ascertain whether increased knowledge of best clinical practice was evident in each group. Seventy-five per cent (144/191) of GPs responded to the pre-intervention questionnaire, 62 % (119/191) post-intervention. Thirty-four per cent (22/64) of GPs in the passive group attended the lecture; 91% (60/66) of the active group engaged in discussion at meetings with the authors. A significantly higher proportion of the active group participants' speaking time, during a sample of four visits, was devoted to verbal indicators of active processing than the passive group lecture attenders (difference = 55%, Fisher's exact test P = 0.002, OR = 11.5, 95% CI 2.1-113.4). Inter-observer agreement on the classification of the verbal evidence was highly statistically significant for all classes (Pearson's product moment correlation, P < 0.0005, r = +0.893 to +0.999) except repetition (P > 0.05, r = +0.407). Median compliance of responses with the guidelines improved by 2.5% within the control group and 4% within the passive, but by 23% within the active. The difference between the changes in the active and control groups was highly statistically significant at 17.5% (Mann-Whitney test, P = 0.004, 95% CI 6-29%). However, for the 10 infections, the median difference between the changes in the passive and control groups was not significant at 3% (P = 0.75, 95% CI -8 to +12. The median difference between changes in the active and passive groups was significant at 17% (P = 0.015, 95% CI 7-24%) in favour of the active. An active educational strategy attracted more participation and was more effective at generating deep cognitive processing than a passive strategy. A large improvement, lasting for at least 12 months, in attitude-compliance with guidelines on the optimal treatment of infections was imparted by the active processing method. A typical passive method was much less popular and had an insignificant impact on attitudes. The findings suggest that initiatives aiming to implement evidence-based guidelines must employ active educational strategies if enduring changes in attitude are to result.
Thermal elastic shock and its effect on TOPEX spacecraft attitude control
NASA Technical Reports Server (NTRS)
Zimbelman, Darrell F.
1991-01-01
Thermal elastic shock (TES) is a twice per orbit impulsive disturbance torque experienced by low-Earth orbiting spacecraft. The fundamental equations used to model the TES disturbance torque for typical spacecraft appendages (e.g., solar arrays and antenna booms) are derived in detail. In particular, the attitude-pointing performance of the TOPEX spacecraft, when subjected to the TES disturbance, is analyzed using a three-axis nonlinear time-domain simulation. Results indicate that the TOPEX spacecraft could exceed its roll-axis attitude-control requirement during penumbral transitions, and remain in violation for approximately 150 sec each orbit until the umbra collapses. A localized active-control system is proposed as a solution to minimize and/or eliminate the degrading effects of the TES disturbance.
ERIC Educational Resources Information Center
Korkmaz, Özgen
2016-01-01
The aim of the study was to present the effect of Lego Mindstorms Ev3 based design activities on students' attitudes towards learning computer programming, self-efficacy beliefs and levels of academic achievement. The research is a pretest-posttest with control group semi-experimental study. The study group of the research consisted of 53 students…
Liu, Li; Liu, Yue-Ping; Wang, Jing; An, Li-Wei; Jiao, Jian-Mei
2016-06-01
To investigate the effects of a knowledge-attitude-behaviour health education model on acquisition of disease-related knowledge and self-management behaviour by patients undergoing maintenance haemodialysis. Patients recently prescribed MHD were randomly assigned to a control group or an intervention group. Control group patients were treated with usual care and general education models. A specialist knowledge-attitude-behaviour health education model was applied to patients in the intervention group. Eighty-six patients were included (n = 43 per group). Before intervention, there were no significant between-group differences in disease knowledge and self-management behaviour. After 6 months' intervention, a significant between-group difference in acquisition of disease knowledge was observed. Self-management behaviour scores (control of body mass, reasonable diet, correct drug intake, physical activity, correct fistula care, disease condition monitoring, psychological and social behaviours) for the intervention group were also higher than those for the control group. These preliminary findings suggest that the knowledge-attitude-behaviour model appears to be a valuable tool for the health education of MHD patients. © The Author(s) 2016.
Liu, Li; Wang, Jing; An, Li-Wei; Jiao, Jian-Mei
2016-01-01
Objective To investigate the effects of a knowledge-attitude-behaviour health education model on acquisition of disease-related knowledge and self-management behaviour by patients undergoing maintenance haemodialysis. Methods Patients recently prescribed MHD were randomly assigned to a control group or an intervention group. Control group patients were treated with usual care and general education models. A specialist knowledge-attitude-behaviour health education model was applied to patients in the intervention group. Results Eighty-six patients were included (n = 43 per group). Before intervention, there were no significant between-group differences in disease knowledge and self-management behaviour. After 6 months’ intervention, a significant between-group difference in acquisition of disease knowledge was observed. Self-management behaviour scores (control of body mass, reasonable diet, correct drug intake, physical activity, correct fistula care, disease condition monitoring, psychological and social behaviours) for the intervention group were also higher than those for the control group. Conclusion These preliminary findings suggest that the knowledge-attitude-behaviour model appears to be a valuable tool for the health education of MHD patients. PMID:26951842
Using memories to motivate future behaviour: an experimental exercise intervention.
Biondolillo, Mathew J; Pillemer, David B
2015-01-01
This study tested a novel memory-based experimental intervention to increase exercise activity. Undergraduate students completed a two-part online survey ostensibly regarding college activity choices. At Time 1, they completed questionnaires that included assessments of exercise-related attitudes, motivation and self-reported behaviours. Next, they described a memory of a positive or negative experience that would increase their motivation to exercise; students in a control condition did not receive a memory prompt. Finally, they rated their intentions to exercise in the future. Eight days following Time 1, students received a Time 2 survey that included an assessment of their self-reported exercise during the prior week. Students in the positive memory condition reported higher levels of subsequent exercise than those in the control condition; students in the negative memory condition reported intermediate levels of exercise. Activating a positive motivational memory had a significant effect on students' self-reported exercise activity even after controlling for prior attitudes, motivation and exercise activity.
ERIC Educational Resources Information Center
Aday, Ronald H.; And Others
1996-01-01
Evaluated effects of a nine-month project that paired fourth graders with elderly volunteers for a number of shared interdisciplinary activities. The Children's Perception of Aging and Elderly inventory posttest scores indicated the experimental group had significantly more positive attitudes toward the elderly than the control group. Results held…
Lau, Bobo Hi-Po; Wong, Daniel F K; Fung, Y L; Zhou, Jillian; Chan, Cecilia L W; Chow, Amy Y M
2018-05-21
Based on the cognitive theory, anxiety arising from the awareness of death and dying may activate dysfunctional attitudes, which may then reduce quality of life. This study examined the interdependence and the mediating role of dysfunctional attitudes on the relationship between death anxiety and quality of life among patients with lung cancer and their caregivers. From March 2016 to April 2017, 173 pairs of patients and their caregivers enrolled in a randomized controlled trial of psychosocial support. Using the baseline data, actor-partner interdependence modelling was used to analyze the relationships among death anxiety, dysfunctional attitudes and quality of life. In patients, death anxiety was related to dependency (β=.51) and self-control (β=-.37); achievement (β=-.21) and self-control (β=.34) were related to quality of life. Among caregivers, death anxiety was related to all three dysfunctional attitudes of their own (βs=.23 to.32); dependency (β=-.22) was associated with quality of life. Caregiver quality of life were also associated with patient self-control (β=.22) and achievement (β=-.18). Patient self-control mediated the links between patient death anxiety with both patient and caregiver quality of life. The relationship between death anxiety and quality of life was mediated by dependency in caregivers. Death anxiety influences dysfunctional attitudes and quality of life of both patients and caregivers. Our results support the relevance of dysfunctional attitudes in understanding the impact of death anxiety and underscore the need for parallel psychosocial interventions. This article is protected by copyright. All rights reserved.
Hypersexuality and high sexual desire: exploring the structure of problematic sexuality.
Carvalho, Joana; Štulhofer, Aleksandar; Vieira, Armando L; Jurin, Tanja
2015-06-01
The concept of hypersexuality has been accompanied by fierce debates and conflicting conclusions about its nature. One of the central questions under the discussion is a potential overlap between hypersexuality and high sexual desire. With the relevant research in its early phase, the structure of hypersexuality remains largely unknown. The aim of the present study was to systematically explore the overlap between problematic sexuality and high sexual desire. A community online survey was carried out in Croatia in 2014. The data were first cluster analyzed (by gender) based on sexual desire, sexual activity, perceived lack of control over one's sexuality, and negative behavioral consequences. Participants in the meaningful clusters were then compared for psychosocial characteristics. To complement cluster analysis (CA), multigroup confirmatory factor analysis (CFA) of the same four constructs was carried out. Indicators representing the proposed structure of hypersexuality were included: sexual desire, frequency of sexual activity, lack of control over one's sexuality, and negative behavioral outcomes. Psychosocial characteristics such as religiosity, attitudes toward pornography, and general psychopathology were also evaluated. CA pointed to the existence of two meaningful clusters, one representing problematic sexuality, that is, lack of control over one's sexuality and negative outcomes (control/consequences cluster), and the other reflecting high sexual desire and frequent sexual activity (desire/activity cluster). Compared with the desire/activity cluster, individuals from the control/consequences cluster reported more psychopathology and were characterized by more traditional attitudes. Complementing the CA findings, CFA pointed to two distinct latent dimensions-problematic sexuality and high sexual desire/activity. Our study supports the distinctiveness of hypersexuality and high sexual desire/activity, suggesting that problematic sexuality might be more associated with the perceived lack of personal control over sexuality and moralistic attitudes than with high levels of sexual desire and activity. © 2015 International Society for Sexual Medicine.
Mineyama, Sachiko; Tsutsumi, Akizumi; Takao, Soshi; Nishiuchi, Kyoko; Kawakami, Norito
2007-03-01
We investigated whether supervisors' listening attitudes and skills were related to working conditions and psychological stress reactions among their subordinates. The subjects included 41 male supervisors and their immediate subordinates (n=203). The supervisors completed a short version of the Active Listening Attitude Scale (ALAS) consisting of two subscales: Listening Attitude and Listening Skill for Active Listening. The subordinates rated working conditions and their psychological stress reactions using selected scales of the Job Content Questionnaire and the Brief Job Stress Questionnaire. Those subordinates who worked under supervisors with a higher score of Listening Attitude and Listening Skill reported a more favorable psychological stress reaction than those who worked under supervisors with a lower score of Listening Attitude and Listening Skill. Those subordinates who worked under supervisors with a higher score of Listening Skill reported higher worksite support than those who worked under supervisors with a lower score of Listening Skill. Those subordinates who worked under supervisors with a higher score of Listening Attitude reported higher job control than those who worked under supervisors with a lower score of Listening Attitude. A supervisor's listening attitude and skill appeared to affect psychological stress reactions predominantly among male subordinates than among female subordinates. Psychological stress reactions were lower among younger subordinates who worked under supervisors with high listening skill, while no statistically difference was observed among older subordinates. These findings suggest that a supervisor's listening attitude and skill have an effect on working conditions and psychological stress reactions among subordinates and that the effects vary according to the subordinates' sex and age.
Radio astronomy Explorer-B postlaunch attitude operations analysis
NASA Technical Reports Server (NTRS)
Werking, R. D.; Berg, R.; Brokke, K.; Hattox, T.; Lerner, G.; Stewart, D.; Williams, R.
1974-01-01
The attitude support activities of the Radio Astronomy Explorer-B are reported. The performance of the spacecraft hardware and software are discussed along with details of the mission events, from launch through main boom deployment. Reproductions of displays are presented which were used during support activities. The interactive graphics proved the support function by providing the quality control necessary to ensure mission success in an environment where flight simulated ground testing of spacecraft hardware cannot be performed.
Design development of the Apollo command and service module thrust vector attitude control systems
NASA Technical Reports Server (NTRS)
Peters, W. H.
1978-01-01
Development of the Apollo thrust vector control digital autopilot (TVC DAP) was summarized. This is the control system that provided pitch and yaw attitude control during velocity change maneuvers using the main rocket engine on the Apollo service module. A list of ten primary functional requirements for this control system are presented, each being subordinate to a more general requirement appearing earlier on the list. Development process functions were then identified and the essential information flow paths were explored. This provided some visibility into the particular NASA/contractor interface, as well as relationships between the many individual activities.
Xia, Kewei; Huo, Wei
2016-05-01
This paper presents a robust adaptive neural networks control strategy for spacecraft rendezvous and docking with the coupled position and attitude dynamics under input saturation. Backstepping technique is applied to design a relative attitude controller and a relative position controller, respectively. The dynamics uncertainties are approximated by radial basis function neural networks (RBFNNs). A novel switching controller consists of an adaptive neural networks controller dominating in its active region combined with an extra robust controller to avoid invalidation of the RBFNNs destroying stability of the system outside the neural active region. An auxiliary signal is introduced to compensate the input saturation with anti-windup technique, and a command filter is employed to approximate derivative of the virtual control in the backstepping procedure. Globally uniformly ultimately bounded of the relative states is proved via Lyapunov theory. Simulation example demonstrates effectiveness of the proposed control scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.
Instructional strategies to improve women's attitudes toward science
NASA Astrophysics Data System (ADS)
Newbill, Phyllis Leary
Although negative attitudes toward science are common among women and men in undergraduate introductory science classes, women's attitudes toward science tend to be more negative than men's. The reasons for women's negative attitudes toward science include lack of self-confidence, fear of association with social outcasts, lack of women role models in science, and the fundamental differences between traditional scientific and feminist values. Attitudes are psychological constructs theorized to be composed of emotional, cognitive, and behavioral components. Attitudes serve functions, including social expressive, value expressive, utilitarian, and defensive functions, for the people who hold them. To change attitudes, the new attitudes must serve the same function as the old one, and all three components must be treated. Instructional designers can create instructional environments to effect attitude change. In designing instruction to improve women's attitudes toward science, instructional designers should (a) address the emotions that are associated with existing attitudes, (b) involve credible, attractive women role models, and (c) address the functions of the existing attitudes. Two experimental instructional modules were developed based on these recommendations, and two control modules were developed that were not based on these recommendations. The asynchronous, web-based modules were administered to 281 undergraduate geology and chemistry students at two universities. Attitude assessment revealed that attitudes toward scientists improved significantly more in the experimental group, although there was no significant difference in overall attitudes toward science. Women's attitudes improved significantly more than men's in both the experimental and control groups. Students whose attitudes changed wrote significantly more in journaling activities associated with the modules. Qualitative analysis of journals revealed that the guidelines worked exactly as predicted for some students.
Abeje, Tadiye; Negera, Edessa; Kebede, Eshetu; Hailu, Tsegaye; Hassen, Ismaile; Lema, Tsehainesh; Yamuah, Lawrence; Shiguti, Birru; Fenta, Melkamu; Negasa, Megersa; Beyene, Demissew; Bobosha, Kidist; Aseffa, Abraham
2016-04-07
Leprosy is a chronic infectious disease of public health importance and one of the leading causes of permanent physical disability. Nevertheless, the drop in prevalence following multidrug therapy has resulted in the neglect of leprosy. The annual incidence of leprosy has remained the same in Ethiopia since decades with more than 76% of the reported new cases coming from Oromia and Amhara Regional States. This study was aimed to assess the knowledge, attitude and skill of general health workers in leprosy control activities at public health facilities in Oromia and Amhara Regional States. A cross-sectional study was conducted from September 2011 to February 2012 at different public health facilities in selected eight zones in Oromia and Amhara Regional States. A multistage sampling method was used to obtain representative samples. High and low endemic zones for leprosy were included in the study in both regional states. Data were collected from general health workers through a structured self-administered questionnaire and at on-site assessment of their performance. Baseline socio-demographic data, health workers' attitude towards leprosy and their knowledge and skill in the management of leprosy were assessed. Bloom's cut off point was used to describe the knowledge and practical skills of the respondents while Likert's scale was used for attitude assessment. A total of 601 general health workers responsible for leprosy control activities at public health facilities were included in knowledge and attitude assessment and 83 of them were subjected to practical evaluation, with on-site observation of how they handle leprosy patients. These included medical doctors (4%), health officers and nurses with Bachelor degree in Science (27%), clinical nurses with diploma (66%) and health assistants (2.8%). The median age of the respondents was 26.0 years and females made up of 45%. Generally the knowledge and skills of the respondents were found to be poor while attitude towards leprosy was positive for the majority of the respondents. The result showed that 519 (86.3%) had poor knowledge. Overall 155 (25.8%) of the respondents had positive attitude towards leprosy while 205 (34.1%) had intermediate (mixed) attitude and 241 (40.1%) had negative attitude to the disease. Among 83 respondents assessed for diagnosis of leprosy only 15(18.0%) diagnosed leprosy correctly. Variation in knowledge and attitude indicated a significant difference (p < 0.05) among different health institutions, professions, gender, in-service training and years of experience. The current finding underlines that although leprosy control activities are integrated to the general health services in the country, the knowledge and skills of leprosy diagnosis, treatment and management by health workers was unsatisfactory. Hence, attention should be given to develop training strategies that can improve health worker knowledge and promote better leprosy management at public health facilities. This could be achieved through pre-service and in-service training and giving adequate emphasis to leprosy related practical work and continuous follow- up.
The effect of a healthy lifestyle programme on 8-9 year olds from social disadvantage.
Breslin, Gavin; Brennan, Deirdre; Rafferty, Ruth; Gallagher, Alison M; Hanna, Donncha
2012-07-01
This study assessed the efficacy of a school-based healthy lifestyle intervention (Sport for LIFE) for increasing physical activity, decreasing sedentary behaviour, reducing screen time behaviour, encouraging healthy attitudes and behaviour to nutrition, and reducing body mass index (BMI) in 8-9-year-old primary school children from lower socioeconomic backgrounds in Northern Ireland. A non-randomised controlled trial of 416 children from 24 schools took part. Schools were randomly assigned to one of two groups, an intervention or control group with 12 schools in each group. The intervention group received a 12-week school-based programme based on social cognitive theory. At baseline and follow-up, groups completed questionnaires assessing physical activity, screen time behaviour and dietary patterns. On each occasion anthropometric assessments of height and weight were taken. Physical activity and sedentary behaviour were measured by accelerometry. Significant effects were observed for vigorous, moderate and light activity for the intervention group at follow-up. Sedentary behaviour was significantly reduced for the intervention group but not for the control group. No significant effects of the intervention on BMI, screen time behaviour or attitudes to nutrition, with the exception of non-core foods, were shown. The programme was effective in increasing physical activity and reducing sedentary behaviour, however no significant changes in screen time behaviour and attitude to nutrition, with the exception of non-core foods, were observed. Future research ideas are offered for tackling low levels of physical activity in children.
The Effect of Physical Activity on Science Competence and Attitude towards Science Content
NASA Astrophysics Data System (ADS)
Klinkenborg, Ann Maria
This study examines the effect of physical activity on science instruction. To combat the implications of physical inactivity, schools need to be willing to consider all possible opportunities for students to engage in moderate-to-vigorous physical activity (MVPA). Integrating physical activity with traditional classroom content is one instructional method to consider. Researchers have typically focused on integration with English/language arts (ELA) and mathematics. The purpose of this study was to determine the effect of physical activity on science competence and attitude towards science. Fifty-three third grade children participated in this investigation; one group received science instruction with a physical activity intervention while the other group received traditional science instruction. Participants in both groups completed a modified version of What I Really Think of Science attitude scale (Pell & Jarvis, 2001) and a physical science test of competence prior to and following the intervention. Children were videotaped during science instruction and their movement coded to measure the proportion of time spent in MVPA. Results revealed that children in the intervention group demonstrated greater MVPA during the instructional period. A moderate to large effect size (partial eta squared = .091) was seen in the intervention group science competence post-test indicating greater understanding of force, motion, work, and simple machines concepts than that of the control group who were less physically active. There was no statistically significant attitude difference between the intervention and control groups post-test, (F(1,51) = .375, p = .543). These results provide evidence that integration can effectively present physical science content and have a positive impact on the number of minutes of health-enhancing physical activity in a school day.
Lamet, Ann R.; Sonshine, Rosanne; Walsh, Sandra M.; Molnar, David; Rafalko, Sharon
2011-01-01
Although numbers of older people are increasing, nursing students have negative attitudes towards older people and do not plan to care for them following graduation. Multiple strategies have been implemented to reverse students' attitudes with mixed results. The purpose of this pilot quasi-experimental study was to test a Creative-Bonding Intervention (CBI) with students implementing art activities with older people to promote students' willingness to take care of them. Using a self-transcendence conceptual framework, control (n = 56) and experimental (n = 14) student groups were pre- and post-tested on attitudes toward older people, self-transcendence, and willingness to serve. The CBI improved attitudes towards older people with negative attitudes significantly changed (P = .008) but with no significant differences on self-transcendence and willingness to serve. However, willingness to serve results approached significance (P = .08). The willingness measure (one question) should be expanded. Curricula changes that incorporate creative activities such as the CBI with larger and equal numbers in student groups and longitudinal follow up to determine long-term results after graduation are suggested. PMID:21994833
Fault Detection and Correction for the Solar Dynamics Observatory Attitude Control System
NASA Technical Reports Server (NTRS)
Starin, Scott R.; Vess, Melissa F.; Kenney, Thomas M.; Maldonado, Manuel D.; Morgenstern, Wendy M.
2007-01-01
The Solar Dynamics Observatory is an Explorer-class mission that will launch in early 2009. The spacecraft will operate in a geosynchronous orbit, sending data 24 hours a day to a devoted ground station in White Sands, New Mexico. It will carry a suite of instruments designed to observe the Sun in multiple wavelengths at unprecedented resolution. The Atmospheric Imaging Assembly includes four telescopes with focal plane CCDs that can image the full solar disk in four different visible wavelengths. The Extreme-ultraviolet Variability Experiment will collect time-correlated data on the activity of the Sun's corona. The Helioseismic and Magnetic Imager will enable study of pressure waves moving through the body of the Sun. The attitude control system on Solar Dynamics Observatory is responsible for four main phases of activity. The physical safety of the spacecraft after separation must be guaranteed. Fine attitude determination and control must be sufficient for instrument calibration maneuvers. The mission science mode requires 2-arcsecond control according to error signals provided by guide telescopes on the Atmospheric Imaging Assembly, one of the three instruments to be carried. Lastly, accurate execution of linear and angular momentum changes to the spacecraft must be provided for momentum management and orbit maintenance. In thsp aper, single-fault tolerant fault detection and correction of the Solar Dynamics Observatory attitude control system is described. The attitude control hardware suite for the mission is catalogued, with special attention to redundancy at the hardware level. Four reaction wheels are used where any three are satisfactory. Four pairs of redundant thrusters are employed for orbit change maneuvers and momentum management. Three two-axis gyroscopes provide full redundancy for rate sensing. A digital Sun sensor and two autonomous star trackers provide two-out-of-three redundancy for fine attitude determination. The use of software to maximize chances of recovery from any hardware or software fault is detailed. A generic fault detection and correction software structure is used, allowing additions, deletions, and adjustments to fault detection and correction rules. This software structure is fed by in-line fault tests that are also able to take appropriate actions to avoid corruption of the data stream.
Peng, Hongjun; Long, Ying; Li, Jie; Guo, Yangbo; Wu, Huawang; Yang, YuLing; Ding, Yi; He, Jianfei; Ning, Yuping
2014-02-18
To date, the relationships between childhood neglect, hypothalamic-pituitary-adrenal (HPA) axis functioning and dysfunctional attitude in depressed patients are still obscure. The Childhood Trauma Questionnaire (CTQ) was used to assess childhood emotional neglect and physical neglect. Twenty-eight depressed patients with childhood neglect and 30 depressed patients without childhood neglect from Guangzhou Psychiatric Hospital were compared with 29 age- and gender-matched control subjects without childhood neglect and 22 control subjects with childhood neglect. Cortisol awakening response, the difference between the cortisol concentrations at awakening and 30 minutes later, provided a measure of HPA axis functioning. The Dysfunctional Attitude Scale measured cognitive schema. HPA axis functioning was significantly increased in depressed patients with childhood neglect compared with depressed patients without childhood neglect (p < 0.001). HPA axis activity in the control group with childhood neglect was significantly higher than in the depressed group without childhood neglect (p < 0.001). Total scores of childhood neglect were positively correlated with HPA axis functioning and dysfunctional attitude scores, but not with severity of depression. We did not find correlations with HPA axis functioning and dysfunctional attitude or with the Hamilton Rating Scale for Depression scores. Childhood neglect may cause hyperactivity of the HPA axis functioning and dysfunctional attitude, but does not affect depression severity.
Influence of attitudes on the intention to use condoms in Quebec sexually active male adolescents.
Nguyen, M N; Saucier, J F; Pica, L A
1994-05-01
The purpose of this study was to determine the influence of attitudes and other variables on the intention to use condoms in sexually active male adolescents. The survey was conducted from April to June 1989 on a sample of 433 sexually active boys aged 12-19 years registered in secondary schools in Laval, Quebec. Information on condoms provided by parents, peers, school, or media had no positive effect on male adolescents' intention to use condoms. Having a favorable attitude towards contraceptive responsibility, however, was significantly associated with the outcome variable. Endorsement of this responsibility seemed short-lived being replaced by the birth control pill in older adolescents. The study also found that in younger adolescents, intention to use condoms was significantly associated with supportive parental attitudes. The results of this study highlight the importance of developing strategies to encourage sexually active male adolescents to assume greater responsibility for using condoms, and suggest that in order for programs to be effective, STD and acquired immunodeficiency syndrome prevention should be done at younger ages while encouraging parents to take a greater role in sex education.
The effect of exposure to a condom script on attitudes toward condoms.
Kyes, K B; Brown, I S; Pollack, R H
1991-01-01
The effect of reading an erotic script that described condom placement on attitudes toward condom use was investigated in 102 male and 108 female US university students. It was hypothesized that, when integrated into an erotic script, condom use would become viewed as a pleasurable activity rather than just a means of avoiding pregnancy or disease. Controls received identical scripts except that the use of condoms was omitted or received no stories. Subjects who read the erotic accounts exhibited a positive change from pretest to posttest in attitudes toward condom use, but there was no difference in this outcome between condom story and no-condom erotic story conditions. In women, but not men, a high level of arousal induced by the script was associated with negative attitudes toward condoms, suggesting that males and females may require different reading materials. Given the finding, at least in women, of an inverse relationship between explicit eroticism/sexual arousal and condom attitude scores, a 2nd experiment involving less explicit stories written by college students was conducted. Here, 100 men and 100 women students received erotic stories that either featured or did not include condom use. Again, males who read stories incorporating condom placement held more positive attitudes toward condom use than same-sex controls, but women were not affected by the manipulation. For women, a positive attitude toward condom use was associated only with history of sexual activity. Helpful would be the preparation of erotic scripts that appeal to both sexes given the demonstrated effectiveness of this social learning technique with the male subjects in both experiments.
Lwin, May O; Malik, Shelly
2014-01-01
This study examines the effectiveness of incorporating exergaming into physical education lessons as a platform for imparting health education messages and influencing children's beliefs about and attitudes toward physical activity. The authors launched a 6-week intervention program using Nintendo Wii games coupled with protection motivation theory-based health messaging among 5th-grade school children in Singapore. Results indicated that when children who were exposed to threat-framed messages played Wii exergames during physical education lessons, they reported more positive physical activity attitude, self-efficacy, and perceived behavioral control than did those who underwent regular physical education lessons and were exposed to the same message. In addition, among children playing Wii, the threat and coping frames had similar effects on the degree of message influence on physical activity attitudes and beliefs. The implications for schools, parents, and health policy are discussed.
A feasibility study regarding the addition of a fifth control to a rotorcraft in-flight simulator
NASA Technical Reports Server (NTRS)
Turner, Simon; Andrisani, Dominick, II
1992-01-01
The addition of a large movable horizontal tail surface to the control system of a rotorcraft in-flight simulator being developed from a Sikorsky UH-60A Black Hawk Helicopter is evaluated. The capabilities of the control surface as a trim control and as an active control are explored. The helicopter dynamics are modeled using the Generic Helicopter simulation program developed by Sikorsky Aircraft. The effect of the horizontal tail on the helicopter trim envelope is examined by plotting trim maps of the aircraft attitude and controls as a function of the flight speed and horizontal tail incidence. The control power of the tail surface relative to that of the other controls is examined by comparing control derivatives extracted from the simulation program over the flight speed envelope. The horizontal tail's contribution as an active control is evaluated using an explicit model following control synthesis involving a linear model of the helicopter in steady, level flight at a flight speed of eighty knots. The horizontal tail is found to provide additional control flexibility in the longitudinal axis. As a trim control, it provides effective control of the trim pitch attitude at mid to high forward speeds. As an active control, the horizontal tail provides useful pitching moment generating capabilities at mid to high forward speeds.
Attitudes and exercise adherence: test of the Theories of Reasoned Action and Planned Behaviour.
Smith, R A; Biddle, S J
1999-04-01
Three studies of exercise adherence and attitudes are reported that tested the Theory of Reasoned Action and the Theory of Planned Behaviour. In a prospective study of adherence to a private fitness club, structural equation modelling path analysis showed that attitudinal and social normative components of the Theory of Reasoned Action accounted for 13.1% of the variance in adherence 4 months later, although only social norm significantly predicted intention. In a second study, the Theory of Planned Behaviour was used to predict both physical activity and sedentary behaviour. Path analyses showed that attitude and perceived control, but not social norm, predicted total physical activity. Physical activity was predicted from intentions and control over sedentary behaviour. Finally, an intervention study with previously sedentary adults showed that intentions to be active measured at the start and end of a 10-week intervention were associated with the planned behaviour variables. A multivariate analysis of variance revealed no significant multivariate effects for time on the planned behaviour variables measured before and after intervention. Qualitative data provided evidence that participants had a positive experience on the intervention programme and supported the role of social normative factors in the adherence process.
Kalolo, Albino; Kibusi, Stephen Matthew
2015-11-13
Despite the declining trends of Human immunodeficiency virus (HIV) infection in Sub-Saharan Africa (SSA), unsafe sexual behaviours among adolescents still represent a public health challenge. It is important to understand factors acting at different levels to influence sexual behaviour among adolescents. This study examined the influence of perceived behaviour control, subjective norms, attitudes and empowerment on intention to use condoms and reported use of condoms among adolescents in rural Tanzania. We used a questionnaire to collect data from 403 adolescents aged 14 through 19 years from nine randomly selected secondary schools in the Newala district located in the Southern part of Tanzania. The self-administered questionnaire collected information on sexual practices and factors such as attitudes, subjective norms, perceived behaviour control and empowerment. Binary logistic regression was performed to identify factors associated with intention to use and reported use of condoms. Sexually active adolescents constituted 40.6 % of the sample, among them 49.7 % did not use a condom at last sexual intercourse and 49.8 % had multiple sex partners. Many (85 %) of sexually active respondents had their sexual debut between the ages of 14 to 17 years. Girls became sexually active earlier than boys. Perceived behaviour control predicted intentions to use condoms (AOR = 3.059, 95 % CI 1.324-7.065), thus demonstrating its importance in the decision to use a condom. Empowerment (odds ratio = 3.694, 95 % CI 1.295-10.535) and a positive attitude (AOR = 3.484, 95 % CI 1.132-10.72) predicted reported condom use, thus turning the decision to actions. Subjective norms had only indirect effects on intention and reported use of condoms. The findings suggest that unsafe sex practices are prevalent among school adolescents in rural areas of Tanzania. Perceived behaviour control and positive attitudes predict intensions to use condoms whereas empowerment predicts reported condom use. The findings may imply that safe sex promotion interventions that simultaneously address socio-cognitive and ecological determinants of sexual behaviours may improve adolescents' safe sex behaviours.
NASA Astrophysics Data System (ADS)
Sun, Ran; Wang, Jihe; Zhang, Dexin; Shao, Xiaowei
2018-02-01
This paper presents an adaptive neural networks-based control method for spacecraft formation with coupled translational and rotational dynamics using only aerodynamic forces. It is assumed that each spacecraft is equipped with several large flat plates. A coupled orbit-attitude dynamic model is considered based on the specific configuration of atmospheric-based actuators. For this model, a neural network-based adaptive sliding mode controller is implemented, accounting for system uncertainties and external perturbations. To avoid invalidation of the neural networks destroying stability of the system, a switching control strategy is proposed which combines an adaptive neural networks controller dominating in its active region and an adaptive sliding mode controller outside the neural active region. An optimal process is developed to determine the control commands for the plates system. The stability of the closed-loop system is proved by a Lyapunov-based method. Comparative results through numerical simulations illustrate the effectiveness of executing attitude control while maintaining the relative motion, and higher control accuracy can be achieved by using the proposed neural-based switching control scheme than using only adaptive sliding mode controller.
Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators
NASA Technical Reports Server (NTRS)
Zhou, Zhiqiang
2012-01-01
A paper describes attitude-control algorithms using the combination of magnetic actuators with reaction wheel assemblies (RWAs) or other types of actuators such as thrusters. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for nadir-pointing, pitch, and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude- control accuracy is comparable with RWA-based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude-control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode, and the control accuracy can be maintained. The attitude-control algorithms of the combined actuators are derived, which can guarantee the spacecraft attitude and rates to track the commanded values precisely. Results show that precise attitude tracking can be reached, and the attitude-control accuracy is comparable with 3-axis wheel control.
A hopelessness model of depressive symptoms in youth with epilepsy.
Wagner, Janelle L; Smith, Gigi; Ferguson, Pamela L; Horton, Stephanie; Wilson, Erin
2009-01-01
To test the cognitive diathesis-stress and mediational components of the theory of learned hopelessness in youth with epilepsy. Seventy-seven participants ages 9-17 (35 girls, 42 boys) completed measures of depressive symptoms, hopelessness, self-efficacy for seizure management, and attitude toward epilepsy. Caregivers provided information on seizure activity. Diagnostic and treatment information was obtained via medical record review. Regression analyses revealed that hopelessness mediated the attitude towards epilepsy-depressive symptom relationship. While attitude toward epilepsy and self-efficacy were independent predictors of depressive symptoms, the relationship of attitudes toward epilepsy and depressive symptoms was not enhanced with low self-efficacy for seizure management. Findings support the mediation component of the learned hopelessness theory in youth with epilepsy, suggesting the importance of interventions that assist youth in identifying epilepsy-related aspects of functioning over which they can realistically exercise control and challenging negative thoughts about situations they cannot control.
Muzaffar, Henna; Chapman-Novakofski, Karen; Castelli, Darla M; Scherer, Jane A
2014-01-01
We hypothesized that Theory of Planned Behavior (TPB) constructs (behavioral belief, attitude, subjective norm, perceived behavioral control, knowledge and behavioral intention) regarding preventive behaviors for obesity and type 2 diabetes will change favorably after completing the web-based intervention, HOT (Healthy Outcome for Teens) project, grounded in the TPB; and that passive online learning (POL) group will improve more than the active online learning (AOL) group. The secondary hypothesis was to determine to what extent constructs of the TPB predict intentions. 216 adolescents were recruited, 127 randomly allocated to the treatment group (AOL) and 89 to the control group (POL). The subjects completed a TPB questionnaire pre and post intervention. Both POL and AOL groups showed significant improvements from pretest to posttest survey. However, the results indicated no significant difference between POL and AOL for all constructs except behavioral belief. Correlational analysis indicated that all TPB constructs were significantly correlated with intentions for pretest and posttest for both groups. Attitude and behavioral control showed strongest correlations. Regression analysis indicated that TPB constructs were predictive of intentions and the predictive power improved post intervention. Behavioral control consistently predicted intentions for all categories and was the strongest predictor for pretest scores. For posttest scores, knowledge and attitude were the strongest predictors for POL and AOL groups respectively. Thus, HOT project improved knowledge and the TPB constructs scores for targeted behaviors, healthy eating and physical activity, for prevention of obesity and type 2 diabetes. Published by Elsevier Ltd.
Díaz, Margarita; Mello, Maeve Brito de; Sousa, Maria Helena de; Cabral, Francisco; Castro e Silva, Ricardo de; Campos, Márcia; Faúndes, Anibal
2005-01-01
Three different school-based sex education and citizenship programs in public schools in Rio de Janeiro, Belo Horizonte, and Salvador, Brazil, were evaluated in a cross-sectional study comparing knowledge, attitudes, and practices in sexuality, citizenship, and gender issues among adolescents participating in the programs' activities as compared to adolescents enrolled in schools without such programs (controls). Results showed that Salvador's program achieved good results, with significant changes in knowledge on sexuality and reproductive physiology, attitudes regarding citizenship, and current use of modern contraceptives; Rio de Janeiro's program succeeded in improving students' knowledge of reproductive physiology and attitudes towards sexuality; Belo Horizonte's participants showed greater knowledge of reproductive physiology and STI/HIV prevention but had less positive attitudes towards gender issues, while reporting greater sexual activity. The main difference between Salvador's program and the others was the focus on creative and cultural activities; Belo Horizonte's main difference was its lack of interaction with health services and professionals. However, after the evaluation Belo Horizonte reframed its educational strategies and launched a scaling-up process in a joint effort with the health and school systems.
Ku-Yuan, Lee; Li-Chi, Lan; Jiun-Hao, Wang; Chen-Ling, Fang; Kun-Sun, Shiao
2014-06-04
To control the latent social risk of disease, the government usually spreads accurate information and attempts to improve the public's attitude toward adopting prevention. However, these methods with the Knowledge, Attitudes, and Practices (KAP) model do not always work. Therefore, we used the theory of planned behavior (TPB) to understand dog owners' behavior and distinguished the knowledge effect as objective knowledge (OK) and subjective knowledge (SK). A total of 310 dog owners completed a questionnaire based on our model. We employed structural equation modeling to verify the structural relationships and found three main results. First, our model was fit, and each path was significant. People with better attitudes, stronger subjective norms, and more perceptive behavioral control have stronger behavioral intention. Second, perceived behavioral control, not attitude, was the best predictive index in this model. Finally, on perceived behavioral control, subjective knowledge showed more influence than objective knowledge. We successfully extended TPB to explain the behavioral intention of dog owners and presented more workable recommendations. To reduce the latent social risk of disease, the government should not only address dog owners' attitudes, but also their subjective norms and perceptive behavioral control. Indeed, perceptive behavioral control and SK showed the most influence in this model. It is implied that the self-efficacy of dog owners is the most important factor in such a behavior. Therefore, the government should focus on enhancing dog owners' self-efficacy first while devoted to prevention activities.
Ku-Yuan, Lee; Li-Chi, Lan; Jiun-Hao, Wang; Chen-Ling, Fang; Kun-Sun, Shiao
2014-01-01
To control the latent social risk of disease, the government usually spreads accurate information and attempts to improve the public’s attitude toward adopting prevention. However, these methods with the Knowledge, Attitudes, and Practices (KAP) model do not always work. Therefore, we used the theory of planned behavior (TPB) to understand dog owners’ behavior and distinguished the knowledge effect as objective knowledge (OK) and subjective knowledge (SK). A total of 310 dog owners completed a questionnaire based on our model. We employed structural equation modeling to verify the structural relationships and found three main results. First, our model was fit, and each path was significant. People with better attitudes, stronger subjective norms, and more perceptive behavioral control have stronger behavioral intention. Second, perceived behavioral control, not attitude, was the best predictive index in this model. Finally, on perceived behavioral control, subjective knowledge showed more influence than objective knowledge. We successfully extended TPB to explain the behavioral intention of dog owners and presented more workable recommendations. To reduce the latent social risk of disease, the government should not only address dog owners’ attitudes, but also their subjective norms and perceptive behavioral control. Indeed, perceptive behavioral control and SK showed the most influence in this model. It is implied that the self-efficacy of dog owners is the most important factor in such a behavior. Therefore, the government should focus on enhancing dog owners’ self-efficacy first while devoted to prevention activities. PMID:24901413
Predictors of Condom Use Among Mexican Adolescents
Alvarez, Carmen; Villarruel, Antonia M.; Zhou, Yan; Gallegos, Esther
2012-01-01
Mexican adolescents continue to be at increased risk for HIV infection due to inconsistent condom use. The purpose of this study was to identify predictors of condom use intentions and condom use among Mexican adolescents who participated in a randomized control trial designed to test a sexual-risk reduction intervention. Data from sexually active adolescents 17 to 21 years (n = 157) of age who were assigned to the control group were analyzed 48 months post intervention. Regression analysis showed that positive attitudes toward condoms, subjective norms, and control beliefs significantly explained intention to use condoms (R2 = .75, p < .001). Attitudes toward condoms (β = .67, p < .001), technical skills (β = .13, p = .01), and condom use self-efficacy (β = .24, p < .001) were significant predictors of condom use intention. Compared to those who inconsistently used condoms, adolescents who used condoms consistently had greater intention to use condoms and greater impulse control. Findings suggest that attitudes and control beliefs should be further explored with Mexican adolescents in order to support consistent condom use. PMID:20949835
Cleveland, Lacy M.; Olimpo, Jeffrey T.; DeChenne-Peters, Sue Ellen
2017-01-01
In response to calls for reform in undergraduate biology education, we conducted research examining how varying active-learning strategies impacted students’ conceptual understanding, attitudes, and motivation in two sections of a large-lecture introductory cell and molecular biology course. Using a quasi-experimental design, we collected quantitative data to compare participants’ conceptual understanding, attitudes, and motivation in the biological sciences across two contexts that employed different active-learning strategies and that were facilitated by unique instructors. Students participated in either graphic organizer/worksheet activities or clicker-based case studies. After controlling for demographic and presemester affective differences, we found that students in both active-learning environments displayed similar and significant learning gains. In terms of attitudinal and motivational data, significant differences were observed for two attitudinal measures. Specifically, those students who had participated in graphic organizer/worksheet activities demonstrated more expert-like attitudes related to their enjoyment of biology and ability to make real-world connections. However, all motivational and most attitudinal data were not significantly different between the students in the two learning environments. These data reinforce the notion that active learning is associated with conceptual change and suggests that more research is needed to examine the differential effects of varying active-learning strategies on students’ attitudes and motivation in the domain. PMID:28389428
A blended-learning programme regarding professional ethics in physiotherapy students.
Aguilar-Rodríguez, Marta; Marques-Sule, Elena; Serra-Añó, Pilar; Espí-López, Gemma Victoria; Dueñas-Moscardó, Lirios; Pérez-Alenda, Sofía
2018-01-01
In the university context, assessing students' attitude, knowledge and opinions when applying an innovative methodological approach to teach professional ethics becomes fundamental to know if the used approach is enough motivating for students. To assess the effect of a blended-learning model, based on professional ethics and related to clinical practices, on physiotherapy students' attitude, knowledge and opinions towards learning professional ethics. Research design and participants: A simple-blind clinical trial was performed (NLM identifier NCT03241693) (control group, n = 64; experimental group, n = 65). Both groups followed clinical practices for 8 months. Control group performed a public exposition of a clinical case about professional ethics. By contrast, an 8-month blended-learning programme regarding professional ethics was worked out for experimental group. An online syllabus and online activities were elaborated, while face-to-face active participation techniques were performed to discuss ethical issues. Students' attitudes, knowledge and opinions towards learning professional ethics were assessed. Ethical considerations: The study was approved by the University Ethic Committee of Human Research and followed the ethical principles according to the Declaration of Helsinki. After the programme, attitudes and knowledge towards learning professional ethics of experimental group students significantly improved, while no differences were observed in control group. Moreover, opinions reported an adequate extension of themes and temporization, importance of clinical practices and interest of topics. Case study method and role playing were considered as the most helpful techniques. The blended-learning programme proposed, based on professional ethics and related to clinical practices, improves physiotherapy students' attitudes, knowledge and opinions towards learning professional ethics.
Noise screen for attitude control system
NASA Technical Reports Server (NTRS)
Rodden, John J. (Inventor); Stevens, Homer D. (Inventor); Hong, David P. (Inventor); Hirschberg, Philip C. (Inventor)
2002-01-01
An attitude control system comprising a controller and a noise screen device coupled to the controller. The controller is adapted to control an attitude of a vehicle carrying an actuator system that is adapted to pulse in metered bursts in order to generate a control torque to control the attitude of the vehicle in response to a control pulse. The noise screen device is adapted to generate a noise screen signal in response to the control pulse that is generated when an input attitude error signal exceeds a predetermined deadband attitude level. The noise screen signal comprises a decaying offset signal that when combined with the attitude error input signal results in a net attitude error input signal away from the predetermined deadband level to reduce further control pulse generation.
Evolution of International Space Station GN&C System Across ISS Assembly Stages
NASA Technical Reports Server (NTRS)
Lee, Roscoe; Frank, K. D. (Technical Monitor)
1999-01-01
The Guidance Navigation and Control (GN&C) system for the International Space Station is initially implemented by the Functional Cargo Block (FGB) which was built by the Khrunichev Space Center under direct contract to Boeing. This element (Stage 1A/R) was launched on 20 November 1998 and is currently operating on-orbit. The components and capabilities of the FGB Motion Control System (MCS) are described. The next ISS element, which has GN&C functionality will be the Service Module (SM) built by Rocket Space Corporation-Energia. This module is scheduled for launch (Stage 1R) in early 2000. Following activation of the SM GN&C system, the FGB MCS is deactivated and no longer used. The components and capabilities of the SM GN&C system are described. When a Progress vehicle is attached to the ISS it can be used for reboost operations, based on commands provided by the Mission Control Center-Moscow. When a data connection is implemented between the SM and the Progress, the SM can command the Progress thrusters for attitude control and reboosts. On Stage 5A, the U.S. GN&C system will become activated when the U.S. Laboratory is de loyed and installed (launch schedule is currently TBD). The U.S. GN&C system provides non-propulsive control capabilities to support micro-gravity operations and minimize the use of propellant for attitude control, and an independent capability for determining the ISS state vector, attitude, attitude rate. and time.. The components and capabilities of the U.S. GN&C system are described and the interactions between the U.S. and Russian Segment GN&C systems are also described.
NASA Astrophysics Data System (ADS)
Delavault, Stéphanie; Prieur, Pascal; Liénart, Thomas; Robert, Alain; Guidotti, Pierre-Yves
2018-04-01
Microscope is a CNES-ESA-ONERA-CNRS-OCA-DLR-ZARM mission dedicated to the test of the Equivalence Principle with an improved accuracy of 10-15. The 300 kg drag-free microsatellite was launched on April 25th 2016 into a 710 km dawndusk sun-synchronous orbit for a 2-year mission. To comply with stringent requirements, the drag-free and attitude control system (DFACS) involves the scientific accelerometer as main sensor and a set of 8 cold gas proportional thrusters. Once in mission mode, within the CNES drag-free expertise center (CECT) the DFACS team provides several services to the system and to the scientific mission center: cold gas monitoring and management, `Attitude' ancillary data, DFACS expertise ancillary data. For this purpose, expertise tools have been implemented in the CECT, using the flexibility and efficiency of Matlab™ utilities. This paper presents the role of the CECT within the mission and details the expertise activities of the DFACS team illustrated with some typical in flight results.
Enhanced Attitude Control Experiment for SSTI Lewis Spacecraft
NASA Technical Reports Server (NTRS)
Maghami, Peoman G.
1997-01-01
The enhanced attitude control system experiment is a technology demonstration experiment on the NASA's small spacecraft technology initiative program's Lewis spacecraft to evaluate advanced attitude control strategies. The purpose of the enhanced attitude control system experiment is to evaluate the feasibility of designing and implementing robust multi-input/multi-output attitude control strategies for enhanced pointing performance of spacecraft to improve the quality of the measurements of the science instruments. Different control design strategies based on modern and robust control theories are being considered for the enhanced attitude control system experiment. This paper describes the experiment as well as the design and synthesis of a mixed H(sub 2)/H(sub infinity) controller for attitude control. The control synthesis uses a nonlinear programming technique to tune the controller parameters and impose robustness and performance constraints. Simulations are carried out to demonstrate the feasibility of the proposed attitude control design strategy. Introduction
LQG/LTR optimal attitude control of small flexible spacecraft using free-free boundary conditions
NASA Astrophysics Data System (ADS)
Fulton, Joseph M.
Due to the volume and power limitations of a small satellite, careful consideration must be taken while designing an attitude control system for 3-axis stabilization. Placing redundancy in the system proves difficult and utilizing power hungry, high accuracy, active actuators is not a viable option. Thus, it is customary to find dependable, passive actuators used in conjunction with small scale active control components. This document describes the application of Elastic Memory Composite materials in the construction of a flexible spacecraft appendage, such as a gravity gradient boom. Assumed modes methods are used with Finite Element Modeling information to obtain the equations of motion for the system while assuming free-free boundary conditions. A discussion is provided to illustrate how cantilever mode shapes are not always the best assumption when modeling small flexible spacecraft. A key point of interest is first resonant modes may be needed in the system design plant in spite of these modes being greater than one order of magnitude in frequency when compared to the crossover frequency of the controller. LQG/LTR optimal control techniques are implemented to compute attitude control gains while controller robustness considerations determine appropriate reduced order controllers and which flexible modes to include in the design model. Key satellite designer concerns in the areas of computer processor sizing, material uncertainty impacts on the system model, and system performance variations resulting from appendage length modifications are addressed.
Bich, Tran Huu; Cuong, Nguyen Manh
2017-02-01
To test the hypotheses of positive changes of fathers' knowledge, attitude and involvement in supporting exclusive breastfeeding (EBF) after receiving breastfeeding education materials and counseling services. A quasi-experimental, pre-test-post-test, non-equivalent control group design was used. At baseline, 251 and 241 pregnant women and their husbands were enrolled into the intervention and control groups, respectively. The 1-year intervention targeting fathers included mass media, game show-style community events, group and individual counseling at health facilities and home visits. Compared to fathers in the control group, fathers in the intervention group had higher BF knowledge scores and higher attitude scores reflecting more positive attitudes toward early initiation of BF and 6 months EBF. Fathers in the intervention group were also more likely to report active involvement in supporting mothers to practice EBF during antenatal and postpartum periods. The community-based education model should be maintained and considered for conducting further test in wider application to mobilize fathers in supporting EBF.
CSM docked DAP/orbital assembly bending interaction-axial case
NASA Technical Reports Server (NTRS)
Turnbull, J. F.; Jones, J. E.
1972-01-01
A digital autopilot which can provide attitude control for the entire Skylab orbital assembly using the service module reaction control jets is described. An important consideration is the potential interaction of the control system with the bending modes of the orbital assembly. Two aspects of this potential interaction were considered. The first was the possibility that bending induced rotations feeding back through the attitude sensor into the control system could produce an instability or self-sustained oscillation. The second was whether the jet activity commanded by the control system could produce excessive loads at any of the critical load points of the orbital assembly. Both aspects were studied by using analytic techniques and by running simulations on the all-digital simulator.
The Software Design for the Wide-Field Infrared Explorer Attitude Control System
NASA Technical Reports Server (NTRS)
Anderson, Mark O.; Barnes, Kenneth C.; Melhorn, Charles M.; Phillips, Tom
1998-01-01
The Wide-Field Infrared Explorer (WIRE), currently scheduled for launch in September 1998, is the fifth of five spacecraft in the NASA/Goddard Small Explorer (SMEX) series. This paper presents the design of WIRE's Attitude Control System flight software (ACS FSW). WIRE is a momentum-biased, three-axis stabilized stellar pointer which provides high-accuracy pointing and autonomous acquisition for eight to ten stellar targets per orbit. WIRE's short mission life and limited cryogen supply motivate requirements for Sun and Earth avoidance constraints which are designed to prevent catastrophic instrument damage and to minimize the heat load on the cryostat. The FSW implements autonomous fault detection and handling (FDH) to enforce these instrument constraints and to perform several other checks which insure the safety of the spacecraft. The ACS FSW implements modules for sensor data processing, attitude determination, attitude control, guide star acquisition, actuator command generation, command/telemetry processing, and FDH. These software components are integrated with a hierarchical control mode managing module that dictates which software components are currently active. The lowest mode in the hierarchy is the 'safest' one, in the sense that it utilizes a minimal complement of sensors and actuators to keep the spacecraft in a stable configuration (power and pointing constraints are maintained). As higher modes in the hierarchy are achieved, the various software functions are activated by the mode manager, and an increasing level of attitude control accuracy is provided. If FDH detects a constraint violation or other anomaly, it triggers a safing transition to a lower control mode. The WIRE ACS FSW satisfies all target acquisition and pointing accuracy requirements, enforces all pointing constraints, provides the ground with a simple means for reconfiguring the system via table load, and meets all the demands of its real-time embedded environment (16 MHz Intel 80386 processor with 80387 coprocessor running under the VRTX operating system). The mode manager organizes and controls all the software modules used to accomplish these goals, and in particular, the FDH module is tightly coupled with the mode manager.
An exercise in nostalgia: Nostalgia promotes health optimism and physical activity.
Kersten, Mike; Cox, Cathy R; Van Enkevort, Erin A
2016-10-01
Previous research has shown that nostalgia, a sentimental longing for the past, leads to greater feelings of optimism, with other work demonstrating that optimistic thinking (general & health-orientated) is associated with better physical and psychological health. Integrating these two lines of research, the current studies examined whether nostalgia-induced health optimism promotes attitudes and behaviours associated with better physical well-being. Participants, in three experiments, were randomly assigned to write about either a nostalgic or ordinary event. Following this, everyone completed a measure of health optimism (Studies 1-3), measures of health attitudes (Study 2) and had their physical activity monitored over the course of 2 weeks (Study 3). The results revealed that, in comparison to control conditions, nostalgic reverie led to greater health optimism (Studies 1-3). Further, heightened health optimism following nostalgic reflection led to more positive health attitudes (Study 2), and increased physical activity over a two-week period (i.e. Fitbit activity trackers; Study 3). These findings highlight the importance of nostalgia on health attitudes and behaviours. Specifically, this work suggests that nostalgia can be used as a mechanism to increase the importance, perceived efficacy and behaviour associated with better physical health.
ISS Contingency Attitude Control Recovery Method for Loss of Automatic Thruster Control
NASA Technical Reports Server (NTRS)
Bedrossian, Nazareth; Bhatt, Sagar; Alaniz, Abran; McCants, Edward; Nguyen, Louis; Chamitoff, Greg
2008-01-01
In this paper, the attitude control issues associated with International Space Station (ISS) loss of automatic thruster control capability are discussed and methods for attitude control recovery are presented. This scenario was experienced recently during Shuttle mission STS-117 and ISS Stage 13A in June 2007 when the Russian GN&C computers, which command the ISS thrusters, failed. Without automatic propulsive attitude control, the ISS would not be able to regain attitude control after the Orbiter undocked. The core issues associated with recovering long-term attitude control using CMGs are described as well as the systems engineering analysis to identify recovery options. It is shown that the recovery method can be separated into a procedure for rate damping to a safe harbor gravity gradient stable orientation and a capability to maneuver the vehicle to the necessary initial conditions for long term attitude hold. A manual control option using Soyuz and Progress vehicle thrusters is investigated for rate damping and maneuvers. The issues with implementing such an option are presented and the key issue of closed-loop stability is addressed. A new non-propulsive alternative to thruster control, Zero Propellant Maneuver (ZPM) attitude control method is introduced and its rate damping and maneuver performance evaluated. It is shown that ZPM can meet the tight attitude and rate error tolerances needed for long term attitude control. A combination of manual thruster rate damping to a safe harbor attitude followed by a ZPM to Stage long term attitude control orientation was selected by the Anomaly Resolution Team as the alternate attitude control method for such a contingency.
Attitude and Translation Control of a Solar Sail Vehicle
NASA Technical Reports Server (NTRS)
Singh, Gurkirpal
2008-01-01
A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft s center of mass causes solar-pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sunline, requires a low-authority vane/propulsive subsystem. Translation control of the vehicle is achieved by directing the solar-pressure-induced force in the proper inertial direction. This requires attitude control. Attitude and translation degrees-of-freedom are therefore coupled. A guidance law is proposed, which allows the vehicle to stationkeep at an appropriate point on the inertially-rotating Sun-Earth line. Power requirements for moving the bus are minimal. Extensive software simulations have been performed to demonstrate the feasibility of this concept.
Proximity operations considerations affecting spacecraft design
NASA Technical Reports Server (NTRS)
Staas, Steven K.
1991-01-01
Proximity operations can be defined as the maneuvering of two or more spacecraft within 1 nautical mile range, with relative velocity less than 10 feet per second. The passive vehicle is nontranslating and should provide for maintenance of the desired approach attitude. It must accommodate the active (translating) vehicle induced structural loads and performance characteristics (mating hardware tolerances), and support sensor compatibility (transponder, visual targets, etc.). The active vehicle must provide adequate sensor systems (relative state information, field-of-view, redundancy), flight control hardware (thruster sizing, minimal cross-coupling, performance margins, redundancy) and software (reconfigurable, attitude/rate modes, translation and rotation fine control authority) characteristic, and adequate non-propulsive consumables such as power. Operational concerns must be considered. These include the following: (1) the desired approach trajectory and relative orientation; (2) the active vehicle thruster plume effects (forces, torques, contamination) on the passive vehicle; and (3) procedures for contingencies such as loss of communications, sensor or propulsion failures, and target vehicle loss of control.
Tsang, Tracey W; Kohn, Michael R; Chow, Chin Moi; Singh, Maria Fiatarone
2013-01-01
This randomized, placebo-exercise controlled trial found that 6-months of Kung Fu training improved enjoyment of physical activity more than the placebo-exercise intervention, while both groups improved perceptions of behavioral conduct and changed strategies for physical activity. Importantly, family support for physical activity declined in subjects who had more visits to health care professionals, which is worrisome, as this represents another risk factor for sedentary behavior in this vulnerable cohort that must be overcome for successful, sustained behavioral change. Programs supporting positive attitudes of both adolescents and their families toward physical activity will be necessary to optimize exercise adoption and adherence as a means to combat the obesity epidemic in childhood and adolescence.
Colleary, G; O'Sullivan, K; Griffin, D; Ryan, C G; Martin, D J
2017-12-01
To investigate the effect of pain neurophysiology education (PNE) on student physiotherapists': (1) knowledge of chronic pain; (2) attitudes towards patients with chronic pain; and (3) clinical recommendations for patients with chronic pain. Multicentre single-blind randomised controlled trial. One UK and one Irish university. Seventy-two student physiotherapists. Participants received either PNE (intervention) or a control education. Both were delivered in a 70-minute group lecture. (1) The Revised Pain Neurophysiology Quiz to assess knowledge; (2) the Health Care Pain Attitudes and Impairment Relationship Scale (HC-PAIRS) to assess attitudes; and (3) a case vignette to assess the appropriateness of clinical recommendations. Post education, the PNE group had a greater increase in pain neurophysiology knowledge [mean difference 4.0 (95% confidence interval 3.2 to 4.7), P<0.01] and more improved attitudes [-17.5 (95% confidence interval -22.1 to -12.9), P<0.01] compared with the control group. Post education, students in the PNE group were more likely to make appropriate recommendations regarding work (94% vs 56%), exercise (92% vs 56%), activity (94% vs 67%) and bed rest (69% vs 33%) compared with those in the control group (P<0.05). The improvements in knowledge, attitudes and recommendations for pain management show that PNE is a potentially valuable part of the education of physiotherapy students, and could be used on a more widespread basis. There is a need to investigate whether these findings can be replicated in other healthcare professions, and how well these reported changes lead to changes in actual clinical behaviour and the clinical outcomes of patients. Copyright © 2017 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
Liu, Qing-Min; Ren, Yan-Jun; Cao, Cheng-Jian; Liu, Bing; Lv, Jun; Li, Li-Ming
2013-08-01
To investigate the relations between training and both the attitude and practice on smoking control among community medical staff members in Hangzhou, Zhejiang province. Three representative districts including Xiacheng, Gongshu and Westlake were chosen from Hangzhou city. Questionnaire survey was applied to collect information from the related community medical staff members. The survey mainly contained three aspects: knowledge, attitude and practice regarding smoking control involved in the community medical activities. Availability and application of the resources on smoking cessation were also studied. Logistic regression analysis was applied to explore the factors associated with the smoking control training programs. Differences of rates between groups were assessed with chi-square statistics. Wilcoxon rank sum test was used to study the relationships among knowledge, attitude and practice related to smoking control programs, targeted to the community medical staff members. Eight hundred forty-six community medical workers were involved. Sixty-five percent of the community medical staff members had learned related knowledge on smoking control. Proportion of the community medical staff who had taken lessons on smoking control with 3-10 working years was 1.77 times more than the ones with experience less than two years (OR = 1.77, 95% CI: 1.25-2.51). Eighty-eight point seven percent of the medical staff who had received smoking control training programs were identified with the consciousness that they should advise the patients to quit smoking, comparing to the proportion 81.60% (Z=-2.87, P=0.00) in the control group. In terms of the practice regarding smoking control, data showed that 21.62% of the medical staff who had received smoking control training programs would provide 'how to quit smoking' to more than 90% of the smoking patients, while the proportion in the control group was 10.65% (Z = -5.68, P = 0.00). The use of drugs, traditional Chinese medicine therapy and the smoking cessation hotline rate were all less than 30%. The training programs being used on smoking control seemed useful in improving the consciousness and practice towards the smoking control programs during their medical activities among the community medical staff members.
But I Trust My Teen: Parents' Attitudes and Response to a Parental Monitoring Intervention
Metzger, Aaron; Ice, Christa; Cottrell, Lesley
2012-01-01
Parental knowledge gained from monitoring activities protects against adolescent risk involvement. Parental monitoring approaches are varied and may be modified with successful interventions but not all parents or adolescents respond to monitoring programs the same way. 339 parent-adolescent dyads randomized to receive a parental monitoring intervention and 169 parent-adolescent dyads in the control group were followed for one year over four measurement periods. Parent attitudes about the usefulness of monitoring, the importance of trust and respecting their teens' privacy, and the appropriateness of adolescent risk-taking behavior and experimentation were examined as predictors of longitudinal change in parental monitoring and open communication. Similar effects were found in both the intervention and control group models regarding open communication. Parental attitudes impacted longitudinal patterns of teen-reported parent monitoring, and these patterns differed across experimental groups. In the intervention group, parents' beliefs about the importance of trust and privacy were associated with a steeper decline in monitoring across time. Finally, parents' attitudes about the normative nature of teen experimentation were associated with a quadratic parental monitoring time trend in the intervention but not the control group. These findings suggest that parental attitudes may impact how families respond to an adolescent risk intervention. PMID:22720144
Predicted torque equilibrium attitude utilization for Space Station attitude control
NASA Technical Reports Server (NTRS)
Kumar, Renjith R.; Heck, Michael L.; Robertson, Brent P.
1990-01-01
An approximate knowledge of the torque equilibrium attitude (TEA) is shown to improve the performance of a control moment gyroscope (CMG) momentum management/attitude control law for Space Station Freedom. The linearized equations of motion are used in conjunction with a state transformation to obtain a control law which uses full state feedback and the predicted TEA to minimize both attitude excursions and CMG peak and secular momentum. The TEA can be computationally determined either by observing the steady state attitude of a 'controlled' spacecraft using arbitrary initial attitude, or by simulating a fixed attitude spacecraft flying in desired orbit subject to realistic environmental disturbance models.
Correlates of Young Men’s Intention to Discuss Birth Control with Female Partners
Masters, N. Tatiana; Morrison, Diane M.; Querna, Katherine; Casey, Erin A.; Beadnell, Blair
2016-01-01
CONTEXT Heterosexually active men who wish to prevent conception, but are not willing to use condoms consistently, need to discuss birth control with female partners. Improving the understanding of correlates of men’s intention to have such discussions is one step toward supporting this health-facilitating behavior. METHODS A sample of 372 heterosexually active men aged 18–25 were recruited and surveyed online between December 2010 and June 2011. Men answered questions on attitudes toward, norms regarding and self-efficacy about discussing birth control, and about endorsement of two sexual scripts. Multiple regression analyses tested these measures’ associations with intention to discuss birth control, controlling for age and relationship status. RESULTS Attitudes, norms and self-efficacy were each positively associated with men’s intention to discuss birth control, accounting for 34% of variance. The more strongly men endorsed a traditional masculinity sexual script, the less likely they were to intend to discuss birth control (coefficient, −0.2). Endorsement of an alternative, gender-equitable “sex-positive woman” script, which emphasizes sexual pleasure and emotional connection as goals for both partners, had no association with intention. CONCLUSION Strategies that merit further exploration as potential supports for men’s intention to discuss birth control include improving men’s self-efficacy and positive attitudes and norms pertaining to such discussions, and reducing belief in traditionally masculine sexual scripts or transforming them to include discussing birth control. Future research should work both experimentally and longitudinally to document each element of the process that ends with men’s full participation in effective contraceptive use. PMID:27802365
Correlates of Young Men's Intention to Discuss Birth Control with Female Partners.
Masters, N Tatiana; Morrison, Diane M; Querna, Katherine; Casey, Erin A; Beadnell, Blair
2017-03-01
Heterosexually active men who wish to prevent conception, but are not willing to use condoms consistently, need to discuss birth control with female partners. Improving the understanding of correlates of men's intention to have such discussions is one step toward supporting this health-facilitating behavior. A sample of 372 heterosexually active men aged 18-25 were recruited and surveyed online between December 2010 and June 2011. Men answered questions on attitudes toward, norms regarding and self-efficacy about discussing birth control, and about endorsement of two sexual scripts. Multiple regression analyses tested these measures' associations with intention to discuss birth control, controlling for age and relationship status. Attitudes, norms and self-efficacy were each positively associated with men's intention to discuss birth control, accounting for 34% of variance. The more strongly men endorsed a traditional masculinity sexual script, the less likely they were to intend to discuss birth control (coefficient, -0.2). Endorsement of an alternative, gender-equitable "sex-positive woman" script, which emphasizes sexual pleasure and emotional connection as goals for both partners, had no association with intention. Strategies that merit further exploration as potential supports for men's intention to discuss birth control include improving men's self-efficacy and positive attitudes and norms pertaining to such discussions, and reducing belief in traditionally masculine sexual scripts or transforming them to include discussing birth control. Future research should work both experimentally and longitudinally to document each element of the process that ends with men's full participation in effective contraceptive use. Copyright © 2016 by the Guttmacher Institute.
NASA Astrophysics Data System (ADS)
Koksal, Ela Ayse; Berberoglu, Giray
2014-01-01
The purpose of this study is to investigate the effectiveness of guided-inquiry approach in science classes over existing science and technology curriculum in developing content-based science achievement, science process skills, and attitude toward science of grade level 6 students in Turkey. Non-equivalent control group quasi-experimental design was used to investigate the treatment effect. There were 162 students in the experimental group and 142 students in the control group. Both the experimental and control group students took the Achievement Test in Reproduction, Development, and Growth in Living Things (RDGLT), Science Process Skills Test, and Attitudes Toward Science Questionnaire, as pre-test and post-test. Repeated analysis of variance design was used in analyzing the data. Both the experimental and control group students were taught in RDGLT units for 22 class hours. The results indicated the positive effect of guided-inquiry approach on the Turkish students' cognitive as well as affective characteristics. The guided inquiry enhanced the experimental group students' understandings of the science concepts as well as the inquiry skills more than the control group students. Similarly, the experimental group students improved their attitudes toward science more than the control group students as a result of treatment. The guided inquiry seems a transition between traditional teaching method and student-centred activities in the Turkish schools.
NASA Technical Reports Server (NTRS)
Rodden, John James (Inventor); Price, Xenophon (Inventor); Carrou, Stephane (Inventor); Stevens, Homer Darling (Inventor)
2002-01-01
A control system for providing attitude control in spacecraft. The control system comprising a primary attitude reference system, a secondary attitude reference system, and a hyper-complex number differencing system. The hyper-complex number differencing system is connectable to the primary attitude reference system and the secondary attitude reference system.
Barthalos, Istvan; Dorgo, Sandor; Kopkáné Plachy, Judit; Szakály, Zsolt; Ihász, Ferenc; Ráczné Németh, Teodóra; Bognár, József
2016-10-01
Nursing home residing older adults often experience fear of sickness or death, functional impairment and pain. It is difficult for these older adults to maintain a physically active lifestyle and to keep a positive outlook on life. This study evaluated the changes in quality of life, attitude to aging, assertiveness, physical fitness and body composition of nursing home residing elderly through a 15-week organized resistance training based physical activity program. Inactive older adults living in a state financed nursing home (N.=45) were randomly divided into two intervention groups and a control group. Both intervention groups were assigned to two physical activity sessions a week, but one of these groups also had weekly discussions on health and quality of life (Mental group). Data on anthropometric measures, fitness performance, as well as quality of life and attitudes to aging survey data were collected. Due to low attendance rate 12 subjects were excluded from the analyses. Statistical analysis included Paired Samples t-tests and Repeated Measures Analysis of Variance. Both intervention groups significantly improved their social participation, and their upper- and lower-body strength scores. Also, subjects in the Mental group showed improvement in agility fitness test and certain survey scales. No positive changes were detected in attitude towards aging and body composition measures in any groups. The post-hoc results suggest that Mental group improved significantly more than the Control group. Regular physical activity with discussions on health and quality of life made a more meaningful difference for the older adults living in nursing home than physical activity alone. Due to the fact that all participants were influenced by the program, it is suggested to further explore this area for better understanding of enhanced quality of life.
Ojulong, J; Mitonga, K H; Iipinge, S N
2013-12-01
Health Sciences students are exposed early to hospitals and to activities which increase their risk of acquiring infections. Infection control practices are geared towards reduction of occurrence and transmission of infectious diseases. To evaluate knowledge and attitudes of infection prevention and control among Health Science students at University of Namibia. To assess students' knowledge and attitudes regarding infection prevention and control and their sources of information, a self-administered questionnaire was used to look at standard precautions especially hands hygiene. One hundred sixty two students participated in this study of which 31 were medical, 17 were radiography and 114 were nursing students. Medical students had better overall scores (73%) compared to nursing students (66%) and radiology students (61%). There was no significant difference in scores between sexes or location of the high school being either in rural or urban setting. Serious efforts are needed to improve or review curriculum so that health sciences students' knowledge on infection prevention and control is imparted early before they are introduced to the wards.
Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators
NASA Technical Reports Server (NTRS)
Zhou, Zhiqiang
2010-01-01
The accuracy of spacecraft attitude control using magnetic actuators only is low and on the order of 0.4-5 degrees. The key reason is that the magnetic torque is two-dimensional and it is only in the plane perpendicular to the magnetic field vector. In this paper novel attitude control algorithms using the combination of magnetic actuators with Reaction Wheel Assembles (RWAs) or other types of actuators, such as thrusters, are presented. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for Nadir pointing, pitch and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude control accuracy is comparable with RWAs based attitude control. The algorithms are also useful for the RWAs based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode and the control accuracy can be maintained.
Cooperative control of two active spacecraft during proximity operations. M.S. Thesis - MIT
NASA Technical Reports Server (NTRS)
Polutchko, Robert J.
1989-01-01
A cooperative autopilot is developed for the control of the relative attitude, relative position and absolute attitude of two maneuvering spacecraft during on orbit proximity operations. The autopilot consists of an open-loop trajectory solver which computes a nine dimensional linearized nominal state trajectory at the beginning of each maneuver and a phase space regulator which maintains the two spacecraft on the nominal trajectory during coast phases of the maneuver. A linear programming algorithm is used to perform jet selection. Simulation tests using a system of two space shuttle vehicles are performed to verify the performance of the cooperative controller and comparisons are made to a traditional passive target/active pursuit vehicle approach to proximity operations. The cooperative autopilot is shown to be able to control the two vehicle system when both the would be pursuit vehicle and the target vehicle are not completely controllable in six degrees of freedom. The cooperative controller is also shown to use as much as 37 percent less fuel and 57 percent fewer jet firings than a single pursuit vehicle during a simple docking approach maneuver.
Concentrating solar collector subsystem: Preliminary design package
NASA Technical Reports Server (NTRS)
1977-01-01
Preliminary design data are presented for a concentrating solar collector including an attitude controller. Provided are schedules, technical status, all documents required for preliminary design, and other program activities.
NASA Technical Reports Server (NTRS)
Soosaar, K.
1982-01-01
Some performance requirements and development needs for the design of large space structures are described. Areas of study include: (1) dynamic response of large space structures; (2) structural control and systems integration; (3) attitude control; and (4) large optics and flexibility. Reference is made to a large space telescope.
AOCS operations preparation for the BepiColombo mission to mercury
NASA Astrophysics Data System (ADS)
Steiger, C.; Altay, A.; Montagnon, E.; Companys, V.
2018-06-01
The 2018 ESA/JAXA BepiColombo mission to Mercury features a complex modular design, with two scientific Mercury orbiters and a cruise module. The spacecraft (S/C) and mission design lead to a number of challenges for the attitude and orbit control system (AOCS), including electric propulsion usage during cruise to Mercury, AOCS capability to deal with several S/C configurations, and strict attitude constraints owing to the harsh thermal environment. This paper presents the activities for AOCS operations preparation by ESA/ESOC, covering the current preparation status as well as an outlook on upcoming activities before launch.
NASA Astrophysics Data System (ADS)
Chak, Yew-Chung; Varatharajoo, Renuganth; Razoumny, Yury
2017-04-01
This paper investigates the combined attitude and sun-tracking control problem in the presence of external disturbances and internal disturbances, caused by flexible appendages. A new method based on Pythagorean trigonometric identity is proposed to drive the solar arrays. Using the control input and attitude output, a disturbance observer is developed to estimate the lumped disturbances consisting of the external and internal disturbances, and then compensated by the disturbance observer-based controller via a feed-forward control. The stability analysis demonstrates that the desired attitude trajectories are followed even in the presence of external disturbance and internal flexible modes. The main features of the proposed control scheme are that it can be designed separately and incorporated into the baseline controller to form the observer-based control system, and the combined attitude and sun-tracking control is achieved without the conventional attitude actuators. The attitude and sun-tracking performance using the proposed strategy is evaluated and validated through numerical simulations. The proposed control solution can serve as a fail-safe measure in case of failure of the conventional attitude actuator, which triggered by automatic reconfiguration of the attitude control components.
Changes in sunburn and tanning attitudes among lifeguards over a summer season.
Hiemstra, Marieke; Glanz, Karen; Nehl, Eric
2012-03-01
Skin cancer is one of the most common cancers in the United States. Lifeguards are at increased risk of excessive sun exposure and sunburn. We sought to examine changes in: (1) sunburn frequency over a summer while controlling for sun exposure, sun protection habits, and participation in a skin cancer prevention program; and (2) tanning attitudes while controlling for participation in the program. Participants in this study were lifeguards (n = 3014) at swimming pools participating in the Pool Cool program in 2005. Lifeguards completed surveys at the beginning and end of the summer. Sequential regression analyses were used to assess changes in sunburn frequency and tanning attitudes. Sunburn frequency decreased between baseline and follow-up. Having a sunburn over the summer was significantly predicted by baseline sunburn history, ethnicity, skin cancer risk, and sun exposure. The tanning attitude, "People are more attractive if they have a tan," was significantly predicted from baseline tanning attitude and ethnicity. The second tanning attitude, "It helps to have a good base suntan," was significantly predicted by baseline tanning attitude, ethnicity, basic/enhanced group, and moderate skin cancer risk. Self-reported data and limited generalizability to lifeguards at other outdoor pools are limitations. The findings showed that previous sunburn history is an important predictor of sunburn prospectively. In addition, a more risky tanning attitude is an important predictor of future attitudes toward tanning. Active involvement in targeted prevention programs may help to increase preventive behavior and health risk reduction. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.
Changes in sunburn and tanning attitudes among lifeguards over a summer season
Hiemstra, Marieke; Glanz, Karen; Nehl, Eric
2013-01-01
Background Skin cancer is one of the most common cancers in the United States. Lifeguards are at increased risk of excessive sun exposure and sunburn. Objectives We sought to examine changes in: (1) sunburn frequency over a summer while controlling for sun exposure, sun protection habits, and participation in a skin cancer prevention program; and (2) tanning attitudes while controlling for participation in the program. Methods Participants in this study were lifeguards (n = 3014) at swimming pools participating in the Pool Cool program in 2005. Lifeguards completed surveys at the beginning and end of the summer. Sequential regression analyses were used to assess changes in sunburn frequency and tanning attitudes. Results Sunburn frequency decreased between baseline and follow-up. Having a sunburn over the summer was significantly predicted by baseline sunburn history, ethnicity, skin cancer risk, and sun exposure. The tanning attitude, “People are more attractive if they have a tan,” was significantly predicted from baseline tanning attitude and ethnicity. The second tanning attitude, “It helps to have a good base suntan,” was significantly predicted by baseline tanning attitude, ethnicity, basic/enhanced group, and moderate skin cancer risk. Limitations Self-reported data and limited generalizability to lifeguards at other outdoor pools are limitations. Conclusion The findings showed that previous sunburn history is an important predictor of sunburn prospectively. In addition, a more risky tanning attitude is an important predictor of future attitudes toward tanning. Active involvement in targeted prevention programs may help to increase preventive behavior and health risk reduction. PMID:21745696
Linearizing feedforward/feedback attitude control
NASA Technical Reports Server (NTRS)
Paielli, Russell A.; Bach, Ralph E.
1991-01-01
An approach to attitude control theory is introduced in which a linear form is postulated for the closed-loop rotation error dynamics, then the exact control law required to realize it is derived. The nonminimal (four-component) quaternion form is used to attitude because it is globally nonsingular, but the minimal (three-component) quaternion form is used for attitude error because it has no nonlinear constraints to prevent the rotational error dynamics from being linearized, and the definition of the attitude error is based on quaternion algebra. This approach produces an attitude control law that linearizes the closed-loop rotational error dynamics exactly, without any attitude singularities, even if the control errors become large.
NASA Astrophysics Data System (ADS)
Wilke, Roger Russell
2000-10-01
This study investigated the effects active learning strategies had on college students' achievement, motivation, and self-efficacy, in a human physiology course for non-majors. A continuum-based active learning instructional model was implemented over the course of a semester to assess the effects on the variables and specific student outcomes of learning mentioned above. In addition analyses were conducted to explore what learner characteristics contributed to the successful implementation of the model such as students' gender, classification, major, grade point average, ACT and SAT scores, motivation, and self-efficacy. A quasi-experimental, Solomon-4 Group design was undertaken on 171 students in a small west-Texas university. Treatment groups were taught using the model while controls were taught using traditional lecture methods. Students were administered a comprehensive physiology content exam, sections of the Motivated Strategies for Learning Questionnaire, and attitude surveys to assess the effects of the continuum-based active learning strategies. Factorial analyses indicated the treatment group acquired significantly more content knowledge and were significantly more self-efficacious than students in the control group. There were no significant differences in motivation. Factorial and modified regression analyses in the aptitude by treatment interaction exploration determined that males in the treatment group performed significantly better on the comprehensive physiology content exam versus males in the control group. While females performed better overall than males, there were no significant differences in achievement between females in the treatment group and those in the control. No significant interactions were found for the other learner characteristics. The results also indicated that students' general cognitive ability as measured by their grade point average, ACT, and SAT scores and their self-efficacy contributed significantly to their achievement. Attitude surveys indicated that students in both the treatment and control groups demonstrated a positive attitude toward active learning, believed it helped them to learn the material, and would choose an active learning course in the future if given the opportunity. This study demonstrated that continuum-based active learning strategies used in this context, improved students' content acquisition and self-efficacy and had wide applicability with a number of learner characteristics.
Cogin, Julie Ann; Ng, Ju Li; Lee, Ilro
2016-09-20
We assess how human resource management (HRM) is implemented in Australian hospitals. Drawing on role theory, we consider the influence HRM has on job attitudes of healthcare staff and hospital operational efficiency. We adopt a qualitative research design across professional groups (physicians, nurses, and allied health staff) at multiple levels (executive, healthcare managers, and employee). A total of 34 interviews were carried out and analyzed using NVivo. Findings revealed a predominance of a control-based approach to people management. Using Snell's control framework (AMJ 35:292-327, 1992), we found that behavioral control was the principal form of control used to manage nurses, allied health workers, and junior doctors. We found a mix between behavior, output, and input controls as well as elements of commitment-based HRM to manage senior physicians. We observed low levels of investment in people and a concentration on transactional human resource (HR) activities which led to negative job attitudes such as low morale and frustration among healthcare professionals. While hospitals used rules to promote conformity with established procedures, the overuse and at times inappropriate use of behavior controls restricted healthcare managers' ability to motivate and engage their staff. Excessive use of behavior control helped to realize short-term cost-cutting goals; however, this often led to operational inefficiencies. We suggest that hospitals reduce the profusion of behavior control and increase levels of input and output controls in the management of people. Poor perceptions of HR specialists and HR activities have resulted in HR being overlooked as a vehicle to address the strategic challenges required of health reform and to build an engaged workforce.
3-Axis magnetic control: flight results of the TANGO satellite in the PRISMA mission
NASA Astrophysics Data System (ADS)
Chasset, C.; Noteborn, R.; Bodin, P.; Larsson, R.; Jakobsson, B.
2013-09-01
PRISMA implements guidance, navigation and control strategies for advanced formation flying and rendezvous experiments. The project is funded by the Swedish National Space Board and run by OHB-Sweden in close cooperation with DLR, CNES and the Danish Technical University. The PRISMA test bed consists of a fully manoeuvrable MANGO satellite as well as a 3-axis controlled TANGO satellite without any Δ V capability. PRISMA was launched on the 15th of June 2010 on board DNEPR. The TANGO spacecraft is the reference satellite for the experiments performed by MANGO, either with a "cooperative" or "non-cooperative" behaviour. Small, light and low-cost were the keywords for the TANGO design. The attitude determination is based on Sun sensors and magnetometers, and the active attitude control uses magnetic torque rods only. In order to perform the attitude manoeuvres required to fulfil the mission objectives, using any additional gravity gradient boom to passively stabilize the spacecraft was not allowed. After a two-month commissioning phase, TANGO separated from MANGO on the 11th of August 2010. All operational modes have been successfully tested, and the pointing performance in flight is in accordance with expectations. The robust Sun Acquisition mode reduced the initial tip-off rate and placed TANGO into a safe attitude in <30 min. The Manual Pointing mode was commissioned, and the spacecraft demonstrated the capability to follow or maintain different sets of attitudes. In Sun/Zenith Pointing mode, TANGO points its GPS antenna towards zenith with sufficient accuracy to track as many GPS satellites as MANGO. At the same time, it points its solar panel towards the Sun, and all payload equipments can be switched on without any restriction. This paper gives an overview of the TANGO Attitude Control System design. It then presents the flight results in the different operating modes. Finally, it highlights the key elements at the origin of the successful 3-axis magnetic control strategy on the TANGO satellite.
NASA Astrophysics Data System (ADS)
Inamori, Takaya; Otsuki, Kensuke; Sugawara, Yoshiki; Saisutjarit, Phongsatorn; Nakasuka, Shinichi
2016-11-01
This study proposes a novel method for three-axis attitude control using only magnetic torquers (MTQs). Previously, MTQs have been utilized for attitude control in many low Earth orbit satellites. Although MTQs are useful for achieving attitude control at low cost and high reliability without the need for propellant, these electromagnetic coils cannot be used to generate an attitude control torque about the geomagnetic field vector. Thus, conventional attitude control methods using MTQs assume the magnetic field changes in an orbital period so that the satellite can generate a required attitude control torque after waiting for a change in the magnetic field direction. However, in a near magnetic equatorial orbit, the magnetic field does not change in an inertial reference frame. Thus, satellites cannot generate a required attitude control torque in a single orbital period with only MTQs. This study proposes a method for achieving a rotation about the geomagnetic field vector by generating a torque that is perpendicular to it. First, this study shows that the three-axis attitude control using only MTQs is feasible with a two-step rotation. Then, the study proposes a method for controlling the attitude with the two-step rotation using a PD controller. Finally, the proposed method is assessed by examining the results of numerical simulations.
Seasat-A attitude control system
NASA Technical Reports Server (NTRS)
Weiss, R.; Rodden, J. J.; Hendricks, R. J.
1977-01-01
The Seasat-A attitude control system controls the attitude of the satellite system during injection into final circular orbit after Atlas boost, during orbit adjust and trim phases, and throughout the 3-year mission. Ascent and injection guidance and attitude control are provided by the Agena spacecraft with a gyrocompassed mass expulsion system. On-orbit attitude control functions are performed by a system that has its functional roots in the gravity-gradient momentum bias technology. The paper discusses hardware, control laws, and simulation results.
NASA Astrophysics Data System (ADS)
Ingram, Samantha Jones
The purpose of this study was to investigate the effects of the contextual learning method on science performance, attitudes toward science, and motivational factors that influence high school students to learn science. Gender differences in science performance and attitudes toward science were also investigated. The sample included four tenth-grade classes of African-American students enrolled in Chemistry I. All students were required to review for the Alabama High School Graduation Exam in Science. Students were administered a science pretest and posttest to measure science performance. A two-way analysis of covariance was performed on the test data. The results showed a main effect of contextual learning instruction on science achievement and no significant differences between females' and males' performance in science. The Science Attitude and the Alabama High School Graduation Exam (AHSGE) Review Class Surveys were administered to assess students' beliefs and attitudes toward science. The Science Attitude Survey results indicated a control effect in three subscales: perception of guardian's attitude, attitude toward success in science, and perception of teacher's attitude. No significant differences resulted between males and females in their beliefs about science from the attitude survey. However, students' attitudes toward science were more favorable in the contextual learning classes based on the results of the Review Class Survey. The survey data revealed that both males and females in the contextual classes had positive attitudes toward science and toward being active participants in the learning process. Qualitative data on student motivation were collected to examine the meaningfulness of the contextual learning content and materials. The majority of the students in the treatment (96%) and the control groups (86%) reported high interest in the lesson on Newton's three laws of motion. Both the treatment and the control groups indicated their interest ratings were a result of their prior experiences. This study shows that contextual learning instruction positively influences student motivation, interest, and achievement in science. Student achievement in science improved in the contextual learning classes as a result of increased interest due to learning that emphasized relevancy and purposeful meaning.
Leung, Doris Y P; Chan, Sophia S C; Fu, Idy C Y; Lam, Tai-hing
2011-03-01
Volunteers and staff of women's organisations who are highly active in engaging and providing community service can be recruited to motivate female smokers to quit. We described the knowledge and attitudes regarding tobacco control and smoking cessation among these affiliates in Hong Kong and identified factors associated with the practices of cessation interventions. Eight of 14 women's organisations joining the Women Against Tobacco Taskforce agreed to participate. All staff, volunteers, and members of the eight organisations were invited to complete a self-administered anonymous questionnaire during July and August 2006. A total of 623 out of 771 (80.8%) affiliates responded. Their knowledge on smoking and health (mean = 3.91, SD = 1.44 on a range of 0-7), smoking related diseases (mean = 2.91, SD = 0.97 on a range of 0-4), and women-specific diseases (mean = 2.93, SD = 1.87 on a range of 0-6), was considered to be inadequate. They had positive attitudes towards tobacco control (mean = 3.31, SD = 0.55) and their own role in smoking cessation counselling (mean = 3.19, SD = 0.56) on a 4-point Likert scale and 39.3% reported had attempted to offer quitting advice. Logistic regression analysis found that participants having direct contact with smokers who had a positive attitude towards their own role in smoking cessation counselling (OR = 2.57; 95% CI = 1.67-3.95) and better knowledge of smoking and smoking-related diseases (OR = 1.35; 95% CI = 1.06-1.71) were more likely to provide cessation counselling after controlling for gender; knowledge on smoking and health, and women-specific diseases; attitude towards tobacco control, negative and positive attitudes towards female smokers, and perceived self-efficacy in smoking cessation counselling. Women's organisations showed limited support towards tobacco control and their affiliates had a limited knowledge on smoking and health but had positive attitudes. Appropriate training, capacity building and establishing rapport with women's organisations are needed to promote smoking cessation and to support tobacco control in the community. © 2010 Blackwell Publishing Ltd.
14 CFR 125.225 - Flight data recorders.
Code of Federal Regulations, 2014 CFR
2014-01-01
... acceleration; (5) Heading; (6) Time of each radio transmission to or from air traffic control; (7) Pitch attitude; (8) Roll attitude; (9) Longitudinal acceleration; (10) Control column or pitch control surface... control; (7) Pitch attitude; (8) Roll attitude; (9) Longitudinal acceleration; (10) Pitch trim position...
Determinants of Teachers' Intentions To Teach Physically Active Physical Education Classes.
ERIC Educational Resources Information Center
Martin, Jeffrey J.; Kulinna, Pamela Hodges; Eklund, Robert C.; Reed, Brett
2001-01-01
Investigated elementary and secondary teachers' intentions to teach physically active physical education classes, examining a model hypothesizing that teachers' intentions were determined by subjective norm, attitude, perceived behavioral control, and self-efficacy. Teacher surveys supported the theories of reasoned action and planned behavior.…
Lanyon, S R; Anderson, M L; Reichel, M P
2015-05-01
We aimed to establish the attitudes of South Australian cattle farmers towards endemic animal disease prevention and control, with a particular focus on the awareness of and attitudes towards bovine viral diarrhoea (BVD). This cross-sectional postal survey involved mailing a questionnaire to all South Australian cattle owners with 35 or more head of cattle. Worms and lice were the most common animal disease concerns. Less than half of responding farmers were adequately vaccinating their herds against clostridial diseases, but 53.0% stated that they utilised quarantine procedures. Less than 20% of respondents had actively taken part in BVD educational opportunities, or had vaccinated or tested their herd for BVD; less than 20% of respondents were actively involved in any systematic control of Johne's disease. Overall, farmers' actual knowledge of BVD was lower than their perceived understanding, although their interest in BVD and its control was high. Disease prevention measures such as vaccination, quarantine and participation in systematic control schemes were used by a minority of respondents. The results suggest that respondents acknowledge BVD as an important and relevant disease, despite many believing it was not a problem in their herd. Interest in BVD appears to be high and it is likely that an education program would be well received. © 2015 Australian Veterinary Association.
Attitude control analysis of tethered de-orbiting
NASA Astrophysics Data System (ADS)
Peters, T. V.; Briz Valero, José Francisco; Escorial Olmos, Diego; Lappas, V.; Jakowski, P.; Gray, I.; Tsourdos, A.; Schaub, H.; Biesbroek, R.
2018-05-01
The increase of satellites and rocket upper stages in low earth orbit (LEO) has also increased substantially the danger of collisions in space. Studies have shown that the problem will continue to grow unless a number of debris are removed every year. A typical active debris removal (ADR) mission scenario includes launching an active spacecraft (chaser) which will rendezvous with the inactive target (debris), capture the debris and eventually deorbit both satellites. Many concepts for the capture of the debris while keeping a connection via a tether, between the target and chaser have been investigated, including harpoons, nets, grapples and robotic arms. The paper provides an analysis on the attitude control behaviour for a tethered de-orbiting mission based on the ESA e.Deorbit reference mission, where Envisat is the debris target to be captured by a chaser using a net which is connected to the chaser with a tether. The paper provides novel insight on the feasibility of tethered de-orbiting for the various mission phases such as stabilization after capture, de-orbit burn (plus stabilization), stabilization during atmospheric pass, highlighting the importance of various critical mission parameters such as the tether material. It is shown that the selection of the appropriate tether material while using simple controllers can reduce the effort needed for tethered deorbiting and can safely control the attitude of the debris/chaser connected with a tether, without the danger of a collision.
Srinivasan, Raghavan; Ahmad, Tanwir; Raghavan, Vidya; Kaushik, Manisha; Pathak, Ramakant
2018-03-21
Visceral leishmaniasis (VL) is endemic to 54 districts in 4 states of India. Poor awareness of the disease and inappropriate health-seeking behavior are major challenges to eliminating the disease. Between February 2016 and March 2017, we implemented a behavior change communication (BCC) intervention in 33 districts of Bihar, 4 districts of Jharkhand, and 3 districts of West Bengal using a mix of channels, including group and interpersonal communication, to improve knowledge, attitudes, and practices of communities, frontline health workers, and opinion leaders. We conducted an impact assessment in October 2016, after the second indoor residual spraying (IRS) round, in Bihar and Jharkhand to evaluate the effect of the BCC intervention. Villages in 10 districts of Bihar and 4 districts in Jharkhand were selected for inclusion in the assessment. Selected villages were categorized as either intervention or control based on where project activities were conducted. Households were randomly selected proportional to caste composition, and interviewers surveyed the head of the household on whether the house was sprayed during the last IRS round and on knowledge, attitudes, and practices related to VL. We interviewed 700 households in intervention villages and 350 households in control villages and conducted correlation analysis to explore the association between IRS refusal and socioeconomic variables, and tested for association between IRS refusal and exposure to BCC activities. Odds ratios (ORs) were calculated. We reached an estimated 3.3 million contacts in Bihar and Jharkhand through the intervention's BCC activities. IRS refusal rates were significantly lower in intervention households than control households (mean=7.95% vs. 24.45%, respectively; OR, 0.27; 95% confidence interval [CI], 0.11 to 0.62; P <.001). Households in intervention villages were more aware than those in control villages that VL is spread by sand flies (68.4% vs. 7.4%, respectively; P <.001) and of IRS as an effective control measure (82.3% vs. 41.7%, respectively; P <.001). A greater percentage of households in intervention villages than control villages indicated they would encourage a patient to go to primary health centers for diagnosis and treatment of VL (77.0% vs. 39.4%, respectively) and to encourage others to accept IRS (78.6% vs. 44.6%, respectively; P <.001). Households that were exposed to community-based BCC activities largely using group and interpersonal communication had better knowledge, attitudes, and practices related to VL, including acceptance of IRS as a preventive measure, than households not exposed. BCC activities are thus an important component of VL elimination strategies. © Srinivasan et al.
Carpiniello, Bernardo; Primavera, Diego; Pilu, Alessandra; Vaccargiu, Nicola; Pinna, Federica
2013-12-01
Mentally ill people experience greater difficulty than the general population in exercising regularly. We aimed to evaluate attitudes displayed and barriers perceived towards physical activity in a sample of psychiatric patients. A total of 138 (M = 48, F = 90) patients attending a community mental health centre were compared with a control group made up of 138 subjects not affected by mental disorders matched for gender, mean age and education. Both groups underwent a self-administered questionnaire. Patients reported a more sedentary lifestyle in terms of weekly physical activities and daily hours of exercise; their body mass index (BMI) was significantly higher compared with the BMI of controls (p < 0.002); the mentally ill more frequently reported tiredness (p < 0.001), scarce motivation (p < 0.001) and the illness itself (p = 0.01) as barriers to physical activity; moreover, stating how feeling sad or "distressed" reduced their propensity to physical exercise (p = 0.002). A higher number of patients (p < 0.0001) reported little or no motivation for physical activity, and the experiencing of scarce enjoyment (p < 0.001). A series of barriers may limit regular physical activity in subjects affected by mental disorders; these barriers should be taken into account and appropriately addressed.
1986-05-31
Nonlinear Feedback Control 8-16 for Spacecraft Attitude Maneuvers" 2. " Spacecraft Attitude Control Using 17-35... nonlinear state feedback control laws are developed for space- craft attitude control using the Euler parameters and conjugate angular momenta. Time... Nonlinear Feedback Control for Spacecraft Attitude Maneuvers," to appear in AIAA J. of Guidance, Control, and Dynamics, (AIAA Paper No. 83-2230-CP,
Duncan, Michael J; Rivis, Amanda; Jordan, Caroline
2012-06-01
The aim of this brief report is to report on the utility of the Theory of Planned Behaviour (TPB) for predicting the physical activity intentions and behaviour of British adolescents from lower-than-average socio-economic backgrounds. A prospective questionnaire design was employed with 197, 13-14 year olds (76 males, 121 females). At time 1 participant completed standard measures of TPB variables. One week later (Time 2), participants completed the Physical Activity Questionnaire for Adolescents (PAQ-A) as a measure of physical activity behaviour. Hierarchical regression analyses showed that attitude and perceived behavioural control jointly accounted for 25% of the variance in intention (p = 0.0001). Perceived behavioural control emerged as the only significant predictor of physical activity behaviour and explained 3.7% of the variance (p = 0.001). Therefore, attitude and PBC successfully predicts intention towards physical activity and PBC predicts physical activity behaviour in British adolescents from lower-than-average socio-economic backgrounds. Copyright © 2011 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
[Effectively communicate active listening : Comparison of two concepts].
Martin, O; Rockenbauch, K; Kleinert, E; Stöbel-Richter, Y
2017-09-01
Communication between physicians and patients has a great influence on patient adherence, patient satisfaction and the success of treatment. In this context, patient centered care and emotional support have a high positive impact; however, it is unclear how physicians can be motivated to communicate with patients in an appreciative and empathetic way. The implementation of such behavior requires a multitude of communicative skills. One of them is active listening, which is very important in two respects. On the one hand active listening provides the basis for several conversational contexts as a special communication technique and on the other hand active listening is presented in current textbooks in different ways: as an attitude or as a technique. In light of this, the question arises how active listening should be taught in order to be not only applicable in concrete conversations but also to lead to the highest possible level of patient satisfaction. The aim of this pilot study was to examine some variations in simulated doctor-patient conversations, which are the result of the different approaches to active listening. For this purpose three groups of first semester medical students were recruited, two of which were schooled in active listening in different ways (two groups of six students), i.e. attitude versus technique oriented. The third group (seven students) acted as the control group. In a pre-post design interviews with standardized simulation patients were conducted and subsequently evaluated. The analysis of these interviews was considered from the perspectives of participants and observers as well as the quantitative aspects. This study revealed some interesting tendencies despite its status as a pilot study: in general, the two interventional groups performed significantly better than the control group in which no relevant changes occurred. In a direct comparison, the group in which active listening was taught from an attitude approach achieved better results than the group in which the focus was on the technical aspects of active listening. In the group with active listening schooled as an attitude, the response to the feelings of the standardized simulation patients was significantly better from the perspectives of both participants and observers.
Zhang, Ni; Campo, Shelly; Yang, Jingzhen; Janz, Kathleen F; Snetselaar, Linda G; Eckler, Petya
2015-01-01
Despite the physical and mental health benefits of leisure-time physical activity (LTPA), only about half of college students participate in the recommended amount of LTPA. While college students are avid users of social network sites (SNSs), whether SNSs would be an effective channel for promoting LTPA through peer social support is unclear. The aim of this study was to explore the effects of social support from students' contacts on SNSs on their intention to participate in LTPA, applying the Theory of Planned Behavior. Participants were recruited through a mass e-mail sent to undergraduate students at a large Midwestern university in fall 2011. In total, 439 surveys were analyzed. Descriptive analyses and analysis for mediating effects were conducted. Social support about LTPA from contacts on SNSs has indirect effect on intention through affective attitude, instrumental attitude, and perceived behavioral control (PBC). The results indicate that social support about LTPA from contacts on SNSs might not be effective to change students' intention unless attitudes and PBC are changed. Future interventions aiming to promote students' intention to participate in LTPA by increasing support from contacts on SNSs should increase affective attitude, instrumental attitude, and PBC at the same time.
Remote Spacecraft Attitude Control by Coulomb Charging
NASA Astrophysics Data System (ADS)
Stevenson, Daan
The possibility of inter-spacecraft collisions is a serious concern at Geosynchronous altitudes, where many high-value assets operate in proximity to countless debris objects whose orbits experience no natural means of decay. The ability to rendezvous with these derelict satellites would enable active debris removal by servicing or repositioning missions, but docking procedures are generally inhibited by the large rotational momenta of uncontrolled satellites. Therefore, a contactless means of reducing the rotation rate of objects in the space environment is desired. This dissertation investigates the viability of Coulomb charging to achieve such remote spacecraft attitude control. If a servicing craft imposes absolute electric potentials on a nearby nonspherical debris object, it will impart electrostatic torques that can be used to gradually arrest the object's rotation. In order to simulate the relative motion of charged spacecraft with complex geometries, accurate but rapid knowledge of the Coulomb interactions is required. To this end, a new electrostatic force model called the Multi-Sphere Method (MSM) is developed. All aspects of the Coulomb de-spin concept are extensively analyzed and simulated using a system with simplified geometries and one dimensional rotation. First, appropriate control algorithms are developed to ensure that the nonlinear Coulomb torques arrest the rotation with guaranteed stability. Moreover, the complex interaction of the spacecraft with the plasma environment and charge control beams is modeled to determine what hardware requirements are necessary to achieve the desired electric potential levels. Lastly, the attitude dynamics and feedback control development is validated experimentally using a scaled down terrestrial testbed. High voltage power supplies control the potential on two nearby conductors, a stationary sphere and a freely rotating cylinder. The nonlinear feedback control algorithms developed above are implemented to achieve rotation rate and absolute attitude control. Collectively, these studies decisively validate the feasibility of Coulomb charging for remote spacecraft attitude control.
Attributions and Attitudes of Mothers and Fathers in Jordan.
Al-Hassan, Suha; Takash, Hanan
2011-07-01
OBJECTIVE: The present study examined mean level similarities and differences as well as correlations between mothers' and fathers' attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes in Jordan. DESIGN: Interviews were conducted with both mothers and fathers in 112 families. RESULTS: There were no significant main effects of gender on any of the constructs of interest. Mothers and fathers reported similar levels of attributions regarding uncontrollable success, adult-controlled failure, and child-controlled failure in the same family. Regarding attitudes, mothers and fathers reported greater progressive attitudes than authoritarian attitudes. Large, significant correlations were found for concordance between parents in the same family on all seven attributions and attitudes examined; all remained significant after controlling for parents' age, education, and possible social desirability bias. Significant positive correlations were found for mothers' and fathers' attributions regarding uncontrollable success, adult-controlled failure, child-controlled failure, perceived control over failure, progressive attitudes, authoritarian attitudes, and modernity of attitudes. CONCLUSIONS: This study concluded that in Jordan mothers and fathers hold similar levels of attributions and attitudes.
An active attitude control system for a drag sail satellite
NASA Astrophysics Data System (ADS)
Steyn, Willem Herman; Jordaan, Hendrik Willem
2016-11-01
The paper describes the development and simulation results of a full ADCS subsystem for the deOrbitSail drag sail mission. The deOrbitSail satellite was developed as part of an European FP7 collaboration research project. The satellite was launched and commissioning started on 10th July 2015. Various new actuators and sensors designed for this mission will be presented. The deOrbitSail satellite is a 3U CubeSat to deploy a 4 by 4 m drag sail from an initial 650 km circular polar low earth orbit. With an active attitude control system it will be shown that by maximising the drag force, the expected de-orbiting period from the initial altitude will be less than 50 days. A future application of this technology will be the use of small drag sails as low-cost devices to de-orbit LEO satellites, when they have reached their end of life, without having to use expensive propulsion systems. Simulation and Hardware-in-Loop experiments proved the feasibility of the proposed attitude control system. A magnetic-only control approach using a Y-Thomson spin, is used to detumble the 3U Cubesat with stowed sail and subsequently to 3-axis stabilise the satellite to be ready for the final deployment phase. Minituarised torquer rods, a nano-sized momentum wheel, attitude sensor hardware (magnetometer, sun, earth) developed for this phase will be presented. The final phase will be to deploy and 3-axis stabilise the drag sail normal to the satellite's velocity vector, using a combined Y-momentum wheel and magnetic controller. The design and performance improvements when using a 2-axis translation stage to adjust the sail centre-of-pressure to satellite centre-of-mass offset, will also be discussed, although for launch risk reasons this stage was not included in the final flight configuration. To accurately determine the drag sail's attitude during the sunlit part of the orbit, an accurate wide field of view dual sensor to measure both the sun and nadir vector direction was developed for this mission. The calibration results for this new Cubesat sensor (CubeSense), will also be presented.
Attitude dynamics and control of a spacecraft using shifting mass distribution
NASA Astrophysics Data System (ADS)
Ahn, Young Tae
Spacecraft need specific attitude control methods that depend on the mission type or special tasks. The dynamics and the attitude control of a spacecraft with a shifting mass distribution within the system are examined. The behavior and use of conventional attitude control actuators are widely developed and performing at the present time. However, the advantage of a shifting mass distribution concept can complement spacecraft attitude control, save mass, and extend a satellite's life. This can be adopted in practice by moving mass from one tank to another, similar to what an airplane does to balance weight. Using this shifting mass distribution concept, in conjunction with other attitude control devices, can augment the three-axis attitude control process. Shifting mass involves changing the center-of-mass of the system, and/or changing the moments of inertia of the system, which then ultimately can change the attitude behavior of the system. This dissertation consists of two parts. First, the equations of motion for the shifting mass concept (also known as morphing) are developed. They are tested for their effects on attitude control by showing how shifting the mass changes the spacecraft's attitude behavior. Second, a method for optimal mass redistribution is shown using a combinatorial optimization theory under constraints. It closes with a simple example demonstrating an optimal reconfiguration. The procedure of optimal reconfiguration from one mass distribution to another to accomplish attitude control has been demonstrated for several simple examples. Mass shifting could work as an attitude controller for fine-tuning attitude behavior in small satellites. Various constraints can be applied for different situations, such as no mass shift between two tanks connected by a failed pipe or total amount of shifted mass per pipe being set for the time optimum solution. Euler angle changes influenced by the mass reconfiguration are accomplished while stability conditions are satisfied. In order to increase the accuracy, generally, more than two control systems are installed in a satellite. Combination with another actuator will be examined to fulfill the full attitude control maneuver. Future work can also include more realistic spacecraft design and operational considerations on the behavior of this type of control system.
McEnteggart, Ciara; Barnes-Holmes, Yvonne; Lowe, Rob; Evans, Nicky; Vilardaga, Roger
2017-01-01
Perspective-taking interventions have been shown to improve attitudes toward social outgroups. In contrast, similar interventions have produced opposite effects (i.e., enhanced negativity) in the context of attitudes toward elderly groups. The current study investigated whether a brief perspective-taking intervention enhanced with mindfulness would be associated with less negativity than perspective-taking alone. One hundred five participants were randomly assigned to 1 of 4 conditions which comprised of an active or control perspective-taking component and an active or control mindfulness component. Participants were then administered an Implicit Associated Test to assess implicit biases toward the elderly. Results supported previous findings in that the condition in which perspective-taking was active but mindfulness was inactive was associated with greater negative implicit bias toward the elderly; however, some of this negativity decreased in the active perspective-taking and active mindfulness condition. The current findings and other mixed effects that have emerged from perspective-taking interventions are discussed from a Relational Frame Theory perspective. PMID:29399210
Chung, Louisa Ming Yan; Law, Queenie Pui Sze; Fong, Shirley Siu Ming; Chung, Joanne Wai Yee
2014-08-01
This study's objective was to investigate whether use of an electronic dietary recording system improves nutrition knowledge, eating attitudes and habitual physical activity levels compared to use of a food diary and no self-monitoring. Sixty adults aged 20-60 with a body mass index ≥25 were recruited and randomly assigned to one of three groups: a group using an electronic system (EG), a group using a food diary (FD) and a control group using nothing (CG) to record food intake. All participants took part in three 60-90 nutrition seminars and completed three questionnaires on general nutrition knowledge, habitual physical activity levels and eating attitudes at the beginning and end of the 12-week study. The pre- and post-test scores for each questionnaire were analysed using a paired sample t-test. Significant improvements in the domain of 'dietary recommendations' were found in the EG (p=0.009) and FD groups (p=0.046). Great improvements were found in 'sources of nutrients', 'choosing everyday foods' and 'diet-disease relationships' in EG and FD groups. EG group showed greater improvement in the work index and sport index. An electronic dietary recording system may improve eating and exercise behaviour in a self-monitoring process. Copyright © 2014 Elsevier Ltd. All rights reserved.
Research and training activities of the Joint Institute for Aeronautics and Acoustics
NASA Technical Reports Server (NTRS)
Roberts, L.
1993-01-01
During the period October 1992 to September 1993 progress was made on each of the following tasks: (1) experimental studies of free shear flows; (2) analysis of conical flow; (3) experimental and theoretical studies of vortex flows; and (4) aircraft attitude control using active flow control devices. The details of this work was discussed with the technical and management staff at Ames Research Center.
Endendijk, Joyce J; Beltz, Adriene M; McHale, Susan M; Bryk, Kristina; Berenbaum, Sheri A
2016-10-01
Key questions for developmentalists concern the origins of gender attitudes and their implications for behavior. We examined whether prenatal androgen exposure was related to gender attitudes, and whether and how the links between attitudes and gendered activity interest and participation were mediated by gender identity and moderated by hormones. Gender attitudes (i.e., gender-role attitudes and attitudes about being a girl), gender identity, and gender-typed activities were reported by 54 girls aged 10-13 years varying in degree of prenatal androgen exposure, including 40 girls with classical congenital adrenal hyperplasia (C-CAH) exposed to high prenatal androgens and 14 girls with non-classical (NC) CAH exposed to low, female-typical, prenatal androgens. Both girls with C-CAH and NC-CAH reported positive attitudes about being a girl and egalitarian gender attitudes, consistent with their female-typical gender identity. In contrast, girls with C-CAH had more male-typed activity interest and participation than girls with NC-CAH. Gender attitudes were linked to activities in both groups, with gender identity mediating the links. Specifically, gender-role attitudes and positive attitudes about being a girl were associated with feminine gender identity, which in turn was associated with decreased male-typed activity interests and participation, and increased female-typed activity interests. Our results are consistent with schema theories, with attitudes more closely associated with gender identity than with prenatal androgens.
Croft, Giles P; Williams, John G; Mann, Robin Y; Cohen, David; Phillips, Ceri J
2007-08-01
Hospital episode statistics were originally designed to monitor activity and allocate resources in the NHS. Recently their uses have widened to include analysis of individuals' activity, to inform appraisal and revalidation, and monitor performance. This study investigated physician attitudes to the validity and usefulness of these data for such purposes, and the effect of supporting individuals in data interpretation. A randomised study was conducted with consultant physicians in England, Wales and Scotland. The intervention group was supported by a clinician and an information analyst in obtaining and analysing their own data. The control group was unsupported. Attitudes to the data and confidence in their ability to reflect clinical practice were examined before and after the intervention. It was concluded that hospital episode statistics are not presently fit for monitoring the performance of individual physicians. A more comprehensive description of activity is required for these purposes. Improvements in the quality of existing data through clinical engagement at a local level, however, are possible.
Zou, An-Min; Kumar, Krishna Dev
2012-07-01
This brief considers the attitude coordination control problem for spacecraft formation flying when only a subset of the group members has access to the common reference attitude. A quaternion-based distributed attitude coordination control scheme is proposed with consideration of the input saturation and with the aid of the sliding-mode observer, separation principle theorem, Chebyshev neural networks, smooth projection algorithm, and robust control technique. Using graph theory and a Lyapunov-based approach, it is shown that the distributed controller can guarantee the attitude of all spacecraft to converge to a common time-varying reference attitude when the reference attitude is available only to a portion of the group of spacecraft. Numerical simulations are presented to demonstrate the performance of the proposed distributed controller.
Saber, Fatemeh; Shanazi, Hossein; Sharifirad, Gholamreza; Hasanzadeh, Akbar
2014-01-01
Background: Sedentary life has been recognized as a serious problem in today's Iranian society. Promoting the lifestyle with increased physical activity and prevention of cardiovascular disease (CVD) is imperative. The purpose of this study was identifying the determinants of physical activity in the housewives of Nain city in 2012 based on the theory of planned behavior. Materials and Methods: In this cross-sectional study, 120 housewives were selected by simple random sampling method. Data collection tool was a questionnaire designed based on a standardized and fabricated questionnaire and consisted of four parts. The questionnaire included awareness variables, theory of structures, planned behavior, and physical activity. Data analysis was performed using the SPSS software version 18 and associated statistical tests. Findings: The 120 housewives under study had a mean age of 34.58 ± 6.86 years. The mean scores of awareness, attitude, motivation to perform, subjective norms, and perceived behavioral control variables were 74.1 ± 18.5, 82.6 ± 12.1, 59.4 ± 21.7, 63.2 ± 21.2, and 48.1 ± 12.9 respectively. There was a significant relationship between the motivation for physical activity among women and knowledge (P = 0.02) attitude (P = 0.04) subjective norms (P = 0.002) perceived behavioral control (P = 0.001), and physical activity (P = 0.04). Conclusions: It seems that the housewives, despite being aware of and having a positive attitude on the benefits of physical activity, had a poor lifestyle. Perhaps further studies can help in finding the causes of this issue and the barriers to physical activity such as the conditions and plan for greater measures for improving physical activity, in order to promote women's health which has a significant role in family and community health. PMID:25250360
Nonlinear feedback model attitude control using CCD in magnetic suspension system
NASA Technical Reports Server (NTRS)
Lin, CHIN-E.; Hou, Ann-San
1994-01-01
A model attitude control system for a CCD camera magnetic suspension system is studied in this paper. In a recent work, a position and attitude sensing method was proposed. From this result, model position and attitude of a magnetic suspension system can be detected by generating digital outputs. Based on this achievement, a control system design using nonlinear feedback techniques for magnetic suspended model attitude control is proposed.
Women and Child Care in China: A Firsthand Report.
ERIC Educational Resources Information Center
Sidel, Ruth
This paperback presents an illustrated, first hand report of the changes in attitudes towards women and child care in China since the revolution of 1949. Chinese women are encouraged to take an active part in the country's activities. Extensive governmental programs provide women with birth-control information, prenatal assistance, maternity…
Youth Attitudes towards Tobacco Control Laws: The Influence of Smoking Status and Grade in School
ERIC Educational Resources Information Center
Williams, Terrinieka T.; Jason, Leonard A.; Pokorny, Steven B.
2008-01-01
This study examined adolescent attitudes towards tobacco control laws. An exploratory factor analysis, using surveys from over 9,000 students, identified the following three factors: (1) youth attitudes towards the efficacy of tobacco control laws, (2) youth attitudes towards tobacco possession laws and (3) youth attitudes towards tobacco sales…
Maruf, Fatai Adesina; Ojukwu, C C; Akindele, M O
2018-03-01
Understanding lifestyle behavior among individuals with hypertension is important for achieving hypertension control. This study explored perception, knowledge, attitude and participation in physical activity (PA) among individuals with hypertension attending tertiary hospitals in a south-eastern Nigerian state. This cross-sectional survey involved 200 individuals with hypertension from the Out-Patient Departments of the two teaching hospitals in Anambra State, Nigeria. Information on age, education level, gender, height, sleep duration, perception of PA, knowledge about PA, attitude towards PA, and participation in PA was collected using a self-developed and pilot-tested questionnaire. Blood pressure (BP), height, body weight, and waist circumference were measured using standardized procedures. PA level was assessed using 7-Day International PA Questionnaire. Majority of participants reported good perceptions of PA behavior, in terms of not being discouraged by relations and friends, and of its benefits. They reported good knowledge about PA behavior. The participants demonstrated positive attitude in terms of benefits, importance, and involved risk of PA, and reported high level of participation in PA. There were significant correlations among knowledge about PA, attitude towards PA and participation in PA. PA level generally correlated significantly with attitude and participation in PA CONCLUSIONS: Perceived high level of participation in PA in this study sample can be attributed to their much knowledge and positive attitude towards PA. Increasing the knowledge about PA among individuals with hypertension by creating awareness about benefits and utilization of PA will improve their attitudes towards PA, and thereby fosters their participation in PA.
Statistical Control Paradigm for Aerospace Structures Under Impulsive Disturbances
2006-08-03
attitude control system with an innovative and robust statistical controller design shows significant promise for use in attitude hold mode operation...indicate that the existing attitude control system with an innovative and robust statistical controller design shows significant promise for use in...and three thrusters are for use in controlling the attitude of the satellite. Then the angular momentum of the satellite with three thrusters and a
Chang, Yu-Ting; Hayter, Mark; Lin, Mei-Ling
2014-12-01
This study was designed to explore Taiwanese school students' attitudes toward sexual relationships and premarital sex. This was an exploratory descriptive, qualitative study. Focus groups (N = 8) were conducted with 47 adolescents from three high schools in Taiwan. Transcripts were transcribed and thematically analyzed using Atlas V 5.0. Adolescent attitudes toward sexual relationships and premarital sexual behavior comprise the following three dimensions: (1) external incentives, (2) the developmental process, and (3) internal control. External incentives include the normalization of sexual behavior between peers, the desire to feel included in a group, parental influence, and media influence. The developmental process includes imagining the sexual experience and onset of sexual activity. Internal control includes the fear of pregnancy, the fear of parental rejection, and the fear of being judged. These findings can provide a reference for designing future sex education curricula and counseling programs for adolescents. © The Author(s) 2014.
NASA Astrophysics Data System (ADS)
Woodcock, Gordon; Wingo, Dennis
2006-01-01
A modular design for a solar-electric tug was analyzed to establish flight control requirements and methods. Thrusters are distributed around the periphery of the solar array. This design enables modules to be berthed together to create a larger system from smaller modules. It requires a different flight mode than traditional design and a different thrust direction scheme, to achieve net thrust in the desired direction, observe thruster pointing constraints that avoid plume impingement on the tug, and balance moments. The array is perpendicular to the Sun vector for maximum electric power. The tug may maintain a constant inertial attitude or rotate around the Sun vector once per orbit. Either non-rotating or constant angular velocity rotation offers advantages over the conventional flight mode, which has highly variable roll rates. The baseline single module has 12 thrusters: two 2-axis gimbaling main thrusters, one at each ``end'', and two back-to-back Z axis thrusters at each corner of the array. Thruster pointing and throttling were optimized to maximize net thrust effectiveness while observing constraints. Control design used a spread sheet with Excel Solver to calculate nominal thruster pointing and throttling. These results are used to create lookup tables. A conventional control system generates a thruster pointing and throttling overlay on the nominals to maintain active attitude control. Gravity gradients can cause major attitude perturbations during occultation periods if thrust is off during these periods. Thrust required to maintain attitude is about 4% of system rated power. This amount of power can be delivered by a battery system, avoiding the performance penalty if chemical propulsion thrusters were used to maintain attitude.
NASA Astrophysics Data System (ADS)
Goullioud, Renaud; Alvarez-Salazar, Oscar S.; Nemati, Bijan
2003-02-01
Future space-based optical interferometers such as the Space Interferometer Mission require fringe stabilization to the level of nanometers in order to produce astrometric data at the micro-arc-second level. Even the best attitude control system available to date will not be able to stabilize the attitude of a several thousand pound spacecraft to a few milli-arc-seconds. Active pathlength control is usually implemented to compensate for attitude drift of the spacecraft. This issue has been addressed in previous experiments while tracking bright stars. In the case of dim stars, as the sensor bandwidth falls below one hertz, feedback control will not provide sufficient rejection. However, stabilization of the fringes from a dim-star down to the nanometer level can be done open loop using information from additional interferometers looking at bright guide stars. The STB3 testbed developed at the Jet Propulsion Laboratory features three optical interferometers sharing a common baseline, dynamically representative to the SIM interferometer. An artificial star feeding the interferometers is installed on a separate optics bench. Voice coils are used to simulate the attitude motion of the spacecraft by moving the entire bench. Data measured on STB3 show that fringe motion of a dim star due to spacecraft attitude changes can be attenuated by 80 dB at 0.1Hz without feedback control, using only information from two guide stars. This paper describes the STB3 setup, the pathlength feed-forward architecture, implementation issues and data collected with the system.
Chassin, Laurie; Presson, Clark C.; Sherman, Steven J.; Seo, Dong-Chul; Macy, Jon
2010-01-01
The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly predicted later cessation among those with high levels of experienced failure to control smoking, but only if they had a plan to quit. Because smoking cessation involves both controlled and automatic processes, interventions may need to consider attitude change interventions that focus on both implicit and explicit attitudes. PMID:21198227
Global finite-time attitude consensus tracking control for a group of rigid spacecraft
NASA Astrophysics Data System (ADS)
Li, Penghua
2017-10-01
The problem of finite-time attitude consensus for multiple rigid spacecraft with a leader-follower architecture is investigated in this paper. To achieve the finite-time attitude consensus, at the first step, a distributed finite-time convergent observer is proposed for each follower to estimate the leader's attitude in a finite time. Then based on the terminal sliding mode control method, a new finite-time attitude tracking controller is designed such that the leader's attitude can be tracked in a finite time. Finally, a finite-time observer-based distributed control strategy is proposed. It is shown that the attitude consensus can be achieved in a finite time under the proposed controller. Simulation results are given to show the effectiveness of the proposed method.
Pupil Control Ideology as a Source of Stress: The Student Teacher's Dilemma.
ERIC Educational Resources Information Center
Jones, Dan R.
One type of adaptation made by each student teacher is the development of attitudes toward controlling pupils. The student teachers' attitudes toward pupil control may be at odds with those of other educators and this difference in attitude, particularly in the case of the cooperating teacher, can cause stress. Attitudes toward pupil control can…
Kaplan, Jonas T; Freedman, Joshua; Iacoboni, Marco
2007-01-07
We investigated how political party affiliation and political attitudes modulate neural activity while viewing faces of presidential candidates. Ten registered Democrats and 10 registered Republicans were scanned in an event-related functional MRI paradigm while viewing pictures of the faces of George Bush, John Kerry, and Ralph Nader during the 2004 United States presidential campaign. We found that compared with viewing one's own candidate, viewing the candidate from the opposing political party produced signal changes in cognitive control circuitry in the dorsolateral prefrontal cortex and anterior cingulate, as well as in emotional regions such as the insula and anterior temporal poles. BOLD signal in these regions correlated with subjects' self-reported ratings of how they felt emotionally about the candidates. These data suggest that brain activity when viewing a politician's face is affected by the political allegiance of the viewer and that people regulate their emotional reactions to opposing candidates by activating cognitive control networks.
Examining Implicit Attitudes towards Exercisers with a Physical Disability
Dionne, Cassandra D.; Gainforth, Heather L.; O'Malley, Deborah A.; Latimer-Cheung, Amy E.
2013-01-01
Background. Using measures of explicit attitudes, physical activity status has been established as a factor that reduces the stigma able-bodied people hold towards people with physical disabilities. This phenomenon is called the exerciser stereotype. However, whether the exerciser stereotype exists when using measures of implicit attitudes remains unknown. Objective. The aims of this study were to evaluate the prevalence of negative implicit attitudes towards people with physical disabilities and determine whether implicit attitudes towards people with physical disabilities were influenced by the exerciser stereotype. Methods. One hundred able-bodied participants (82 females, 18 males) completed two implicit association tests (IATs): the Disability-Attitudes IAT and the Disability-Activity IAT. The Disability-Attitudes IAT measured implicit attitudes towards people who were not disabled relative to disabled; the Disability-Activity IAT measured attitudes towards people with a physical disability who were active relative to inactive. Results. Results revealed that 83.8% of participants had negative implicit attitudes towards people with a disability. Participants held more positive attitudes towards active versus inactive people with a physical disability. Conclusions. The study findings indicate that the exerciser stereotype exists implicitly and may undermine negative attitudes towards people with physical disabilities. PMID:23710142
Chassin, Laurie; Presson, Clark C.
2013-01-01
Introduction: This study examined the association between implicit and explicit attitudes toward smoking and support for tobacco control policies. Methods: Participants were from an ongoing longitudinal study of the natural history of smoking who also completed a web-based assessment of implicit attitudes toward smoking (N = 1,337). Multiple regression was used to test the association between covariates (sex, age, educational attainment, parent status, and smoking status), implicit attitude toward smoking, and explicit attitude toward smoking and support for tobacco control policies. The moderating effect of the covariates on the relation between attitudes and support for policies was also tested. Results: Females, those with higher educational attainment, parents, and nonsmokers expressed more support for tobacco control policy measures. For nonsmokers, only explicit attitude was significantly associated with support for policies. For smokers, both explicit and implicit attitudes were significantly associated with support. The effect of explicit attitude was stronger for those with lower educational attainment. Conclusions: Both explicit and implicit smoking attitudes are important for building support for tobacco control policies, particularly among smokers. More research is needed on how to influence explicit and implicit attitudes to inform policy advocacy campaigns. PMID:22581941
Macy, Jonathan T; Chassin, Laurie; Presson, Clark C
2013-01-01
This study examined the association between implicit and explicit attitudes toward smoking and support for tobacco control policies. Participants were from an ongoing longitudinal study of the natural history of smoking who also completed a web-based assessment of implicit attitudes toward smoking (N = 1,337). Multiple regression was used to test the association between covariates (sex, age, educational attainment, parent status, and smoking status), implicit attitude toward smoking, and explicit attitude toward smoking and support for tobacco control policies. The moderating effect of the covariates on the relation between attitudes and support for policies was also tested. Females, those with higher educational attainment, parents, and nonsmokers expressed more support for tobacco control policy measures. For nonsmokers, only explicit attitude was significantly associated with support for policies. For smokers, both explicit and implicit attitudes were significantly associated with support. The effect of explicit attitude was stronger for those with lower educational attainment. Both explicit and implicit smoking attitudes are important for building support for tobacco control policies, particularly among smokers. More research is needed on how to influence explicit and implicit attitudes to inform policy advocacy campaigns.
Passive radiative cooling of a HTS coil for attitude orbit control in micro-spacecraft
NASA Astrophysics Data System (ADS)
Inamori, Takaya; Ozaki, Naoya; Saisutjarit, Phongsatorn; Ohsaki, Hiroyuki
2015-02-01
This paper proposes a novel radiative cooling system for a high temperature superconducting (HTS) coil for an attitude orbit control system in nano- and micro-spacecraft missions. These days, nano-spacecraft (1-10 kg) and micro-spacecraft (10-100 kg) provide space access to a broader range of spacecraft developers and attract interest as space development applications. In planetary and high earth orbits, most previous standard-size spacecraft used thrusters for their attitude and orbit control, which are not available for nano- and micro-spacecraft missions because of the strict power consumption, space, and weight constraints. This paper considers orbit and attitude control methods that use a superconducting coil, which interacts with on-orbit space plasmas and creates a propulsion force. Because these spacecraft cannot use an active cooling system for the superconducting coil because of their mass and power consumption constraints, this paper proposes the utilization of a passive radiative cooling system, in which the superconducting coil is thermally connected to the 3 K cosmic background radiation of deep space, insulated from the heat generation using magnetic holders, and shielded from the sun. With this proposed cooling system, the HTS coil is cooled to 60 K in interplanetary orbits. Because the system does not use refrigerators for its cooling system, the spacecraft can achieve an HTS coil with low power consumption, small mass, and low cost.
Malcolm, Shandey; Huang, Shi; Cordova, David; Freitas, Derek; Arzon, Margaret; Jimenez, Giselle Leon; Pantin, Hilda; Prado, Guillermo
2013-08-01
Hispanic problem behavior youth are at an increased risk of engaging in HIV risk behaviors, including low condom use. However, relatively little research has examined factors that affect condom use in this population. Although research indicates that family processes, such as higher levels of family functioning and open parent-adolescent communication about sex, and condom use attitudes, norms, and control beliefs as depicted by the theory of planned behavior have an effect on condom use behaviors, the combination of the two factors has received minimal attention. The purpose of this study was to examine the effect of family functioning on condom use intentions and behaviors through communication about sex and condom use attitudes, parental norms, and control beliefs. A cross-sectional study of 171 predominately male (73.1%) sexually active Hispanic problem behavior adolescents (mean age = 14.88 years) was conducted. Structural equation modeling was used to test the study hypothesis. Findings largely support the overall model and suggest that family functioning had an indirect effect on condom use intention and behavior through communication about sex, condom use attitudes, and control beliefs. Family functioning, however, did not have an indirect effect on condom use intention and behavior through communication about sex and parental norms. Implications for prevention science and future research are discussed.
NASA Astrophysics Data System (ADS)
Park, Han-Earl; Park, Sang-Young; Kim, Sung-Woo; Park, Chandeok
2013-12-01
Development and experiment of an integrated orbit and attitude hardware-in-the-loop (HIL) simulator for autonomous satellite formation flying are presented. The integrated simulator system consists of an orbit HIL simulator for orbit determination and control, and an attitude HIL simulator for attitude determination and control. The integrated simulator involves four processes (orbit determination, orbit control, attitude determination, and attitude control), which interact with each other in the same way as actual flight processes do. Orbit determination is conducted by a relative navigation algorithm using double-difference GPS measurements based on the extended Kalman filter (EKF). Orbit control is performed by a state-dependent Riccati equation (SDRE) technique that is utilized as a nonlinear controller for the formation control problem. Attitude is determined from an attitude heading reference system (AHRS) sensor, and a proportional-derivative (PD) feedback controller is used to control the attitude HIL simulator using three momentum wheel assemblies. Integrated orbit and attitude simulations are performed for a formation reconfiguration scenario. By performing the four processes adequately, the desired formation reconfiguration from a baseline of 500-1000 m was achieved with meter-level position error and millimeter-level relative position navigation. This HIL simulation demonstrates the performance of the integrated HIL simulator and the feasibility of the applied algorithms in a real-time environment. Furthermore, the integrated HIL simulator system developed in the current study can be used as a ground-based testing environment to reproduce possible actual satellite formation operations.
ERIC Educational Resources Information Center
Hagger, Martin S.; Chatzisarantis, Nikos L. D.; Biddle, Stuart J. H.
2002-01-01
Examined relations between behavior, intentions, attitudes, subjective norms, perceived behavioral control, self-efficacy, and past behaviors using the Theories of Reasoned Action (TRA) and Planned Behavior (TPB) in physical activity. This quantitative integration of the physical activity literature supported the major relationships of the…
Wang, Shuo; Carlton, Elizabeth J.; Chen, Lin; Liu, Yang; Spear, Robert C.
2013-01-01
Health education is an important component of efforts to control schistosomiasis. In China, while education programmes have been implemented intensively, few articles in recent years in either the Chinese or English literature report randomised, controlled interventions of the impacts on knowledge, attitudes and behaviours .Thus, we designed and carried out a cluster-randomised controlled education intervention trial that targeted 706 adults from rural areas in 28 villages in Sichuan, China. We evaluated the effects of the intervention on five endpoints: (1) schistosomiasis knowledge, (2) attitudes towards infection testing and treatment, (3) use of personal protective equipment (PPE), (4) reducing defecation in the field, and (5) reducing dermal contact with potentially contaminated water sources. The results indicated that people in both the intervention and control groups showed improvement in knowledge, attitudes and reduction in field-defecation in the follow-up surveys. However, there was little evidence that suggested statistically significant differences between the two groups regarding any endpoint. Participation in intervention classes was associated with age, gender, occupation and education level. Our study suggests short-term health education interventions may not be effective in improving schistosomiasis knowledge or in the adoption of health-protective behaviours. This might be partially due to the spontaneous learning process of people subject to repeated surveys and other disease control activities. Considering the difficulties of occupationassociated behaviour change and knowledge reinforcement in general, longer-term education programmes should be considered in the future. PMID:23711611
An exploratory pilot study of nurse-midwives' attitudes toward active euthanasia and abortion.
Musgrave, C F; Soudry, I
2000-12-01
Over the past three decades, active euthanasia and abortion have received increasing international attention. Since both these practices are relevant to the role of the nurse-midwife, it is important to know what influences their attitudes towards them. Therefore, the purpose of this study was: 1, to survey the attitudes of nurse-midwives' to active euthanasia and its legalization; 2, to determine the relationship between nurse-midwives' attitudes toward active euthanasia and its legalization, and attitudes toward abortion, self-reported religiosity and religious affiliation. The study setting was an international midwifery conference and the sample consisted of 139 nurse-midwives attending the conference. The majority of nurse-midwives displayed a positive attitude toward active euthanasia and its legalization. In addition, there was a positive relationship between their attitude to abortion and active euthanasia. Self-reported religiosity and religious affiliation were significantly related to attitudes toward active euthanasia and its legalization. An interesting positive relationship between country of practice and attitudes to euthanasia was also found. Nurse-midwives practicing in countries with more liberal euthanasia and assisted suicide legislation were more supportive of active euthanasia. With the increasing acceptance of active euthanasia's legalization, the results of this study pose some ethical questions that nurse-midwives internationally will have to consider.
Cleveland, Lacy M; Olimpo, Jeffrey T; DeChenne-Peters, Sue Ellen
2017-01-01
In response to calls for reform in undergraduate biology education, we conducted research examining how varying active-learning strategies impacted students' conceptual understanding, attitudes, and motivation in two sections of a large-lecture introductory cell and molecular biology course. Using a quasi-experimental design, we collected quantitative data to compare participants' conceptual understanding, attitudes, and motivation in the biological sciences across two contexts that employed different active-learning strategies and that were facilitated by unique instructors. Students participated in either graphic organizer/worksheet activities or clicker-based case studies. After controlling for demographic and presemester affective differences, we found that students in both active-learning environments displayed similar and significant learning gains. In terms of attitudinal and motivational data, significant differences were observed for two attitudinal measures. Specifically, those students who had participated in graphic organizer/worksheet activities demonstrated more expert-like attitudes related to their enjoyment of biology and ability to make real-world connections. However, all motivational and most attitudinal data were not significantly different between the students in the two learning environments. These data reinforce the notion that active learning is associated with conceptual change and suggests that more research is needed to examine the differential effects of varying active-learning strategies on students' attitudes and motivation in the domain. © 2017 L. M. Cleveland et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
Graham, Dan J; Sirard, John R; Neumark-Sztainer, Dianne
2011-02-01
To determine whether adolescent attitudes towards sports, exercise, and fitness predict moderate-to-vigorous physical activity 5 and 10 years later. A diverse group of 1902 adolescents participating in Project Eating and Activity in Teens, reported weekly moderate-to-vigorous physical activity and attitudes toward sports, exercise, and fitness in Eating and Activity in Teens-I (1998-99), Eating and Activity in Teens-II (2003-04), and Eating and Activity in Teens-III (2008-09). Mean moderate-to-vigorous physical activity was 6.4, 5.1, and 4.0 hours/week at baseline, 5-year, and 10-year follow-up, respectively. Attitudes toward sports, exercise, and fitness together predicted moderate-to-vigorous physical activity at 5 and 10 years. Among the predictors of 5- and 10-year moderate-to-vigorous physical activity, attitude's effect size, though modest, was comparable to the effect sizes for sports participation and body mass index. Adolescents with more-favorable attitudes toward sports, exercise, and fitness engaged in approximately 30%-40% more weekly moderate-to-vigorous physical activity at follow-up (2.1 hour/week at 5 years and 1.2 hour/week at 10 years) than those with less-favorable attitudes. Adolescents' exercise-related attitudes predict subsequent moderate-to-vigorous physical activity independent of baseline behavior suggesting that youth moderate-to-vigorous physical activity promotion efforts may provide long-term benefits by helping youth develop favorable exercise attitudes. Copyright © 2010 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
1991-01-01
A study which consisted of a series of design analyses for an Attitude Control System (ACS) to be incorporated into the Re-usable Re-entry Satellite (RRS) was performed. The main thrust of the study was associated with defining the control laws and estimating the mass and power requirements of the ACS needed to meet the specified performance goals. The analyses concentrated on the different on-orbit control modes which start immediately after the separation of the RRS from the launch vehicle. The three distinct on-orbit modes considered for these analyses are as follows: (1) Mode 1 - A Gravity Gradient (GG) three-axis stabilized spacecraft with active magnetic control; (2) Mode 2 - A GG stabilized mode with a controlled yaw rotation rate ('rotisserie') using three-axis magnetic control and also incorporating a 10 N-m-s momentum wheel along the (Z) yaw axis; and (3) Mode 3 - A spin stabilized mode of operation with the spin about the pitch (Y) axis, incorporating a 20 N-m-s momentum wheel along the pitch (Y) axis and attitude control via thrusters. To investigate the capabilities of the different controllers in these various operational modes, a series of computer simulations and trade-off analyses have been made to evaluate the achievable performance levels, and the necessary mass and power requirements.
NASA Astrophysics Data System (ADS)
1991-02-01
A study which consisted of a series of design analyses for an Attitude Control System (ACS) to be incorporated into the Re-usable Re-entry Satellite (RRS) was performed. The main thrust of the study was associated with defining the control laws and estimating the mass and power requirements of the ACS needed to meet the specified performance goals. The analyses concentrated on the different on-orbit control modes which start immediately after the separation of the RRS from the launch vehicle. The three distinct on-orbit modes considered for these analyses are as follows: (1) Mode 1 - A Gravity Gradient (GG) three-axis stabilized spacecraft with active magnetic control; (2) Mode 2 - A GG stabilized mode with a controlled yaw rotation rate ('rotisserie') using three-axis magnetic control and also incorporating a 10 N-m-s momentum wheel along the (Z) yaw axis; and (3) Mode 3 - A spin stabilized mode of operation with the spin about the pitch (Y) axis, incorporating a 20 N-m-s momentum wheel along the pitch (Y) axis and attitude control via thrusters. To investigate the capabilities of the different controllers in these various operational modes, a series of computer simulations and trade-off analyses have been made to evaluate the achievable performance levels, and the necessary mass and power requirements.
Attitude Control Subsystem for the Advanced Communications Technology Satellite
NASA Technical Reports Server (NTRS)
Hewston, Alan W.; Mitchell, Kent A.; Sawicki, Jerzy T.
1996-01-01
This paper provides an overview of the on-orbit operation of the Attitude Control Subsystem (ACS) for the Advanced Communications Technology Satellite (ACTS). The three ACTS control axes are defined, including the means for sensing attitude and determining the pointing errors. The desired pointing requirements for various modes of control as well as the disturbance torques that oppose the control are identified. Finally, the hardware actuators and control loops utilized to reduce the attitude error are described.
Chassin, Laurie; Presson, Clark C; Sherman, Steven J; Seo, Dong-Chul; Macy, Jonathan T
2010-12-01
The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly predicted later cessation among those with high levels of experienced failure to control smoking, but only if they had a plan to quit. Because smoking cessation involves both controlled and automatic processes, interventions may need to consider attitude change interventions that focus on both implicit and explicit attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
NASA Technical Reports Server (NTRS)
DeKock, Brandon; Sanders, Devon; Vanzwieten, Tannen; Capo-Lugo, Pedro
2011-01-01
The FASTSAT-HSV01 spacecraft is a microsatellite with magnetic torque rods as it sole attitude control actuator. FASTSAT s multiple payloads and mission functions require the Attitude Control System (ACS) to maintain Local Vertical Local Horizontal (LVLH)-referenced attitudes without spin-stabilization, while the pointing errors for some attitudes be significantly smaller than the previous best-demonstrated for this type of control system. The mission requires the ACS to hold multiple stable, unstable, and non-equilibrium attitudes, as well as eject a 3U CubeSat from an onboard P-POD and recover from the ensuing tumble. This paper describes the Attitude Control System, the reasons for design choices, how the ACS integrates with the rest of the spacecraft, and gives recommendations for potential future applications of the work.
Hagger, Martin S; Hardcastle, Sarah J; Hingley, Catherine; Strickland, Ella; Pang, Jing; Watts, Gerald F
2016-06-01
Patients with familial hypercholesterolemia (FH) are at markedly increased risk of coronary artery disease. Regular participation in three self-management behaviors, physical activity, healthy eating, and adherence to medication, can significantly reduce this risk in FH patients. We aimed to predict intentions to engage in these self-management behaviors in FH patients using a multi-theory, integrated model that makes the distinction between beliefs about illness and beliefs about self-management behaviors. Using a cross-sectional, correlational design, patients (N = 110) diagnosed with FH from a clinic in Perth, Western Australia, self-completed a questionnaire that measured constructs from three health behavior theories: the common sense model of illness representations (serious consequences, timeline, personal control, treatment control, illness coherence, emotional representations); theory of planned behavior (attitudes, subjective norms, perceived behavioral control); and social cognitive theory (self-efficacy). Structural equation models for each self-management behavior revealed consistent and statistically significant effects of attitudes on intentions across the three behaviors. Subjective norms predicted intentions for health eating only and self-efficacy predicted intentions for physical activity only. There were no effects for the perceived behavioral control and common sense model constructs in any model. Attitudes feature prominently in determining intentions to engage in self-management behaviors in FH patients. The prominence of these attitudinal beliefs about self-management behaviors, as opposed to illness beliefs, suggest that addressing these beliefs may be a priority in the management of FH.
Attitude control with realization of linear error dynamics
NASA Technical Reports Server (NTRS)
Paielli, Russell A.; Bach, Ralph E.
1993-01-01
An attitude control law is derived to realize linear unforced error dynamics with the attitude error defined in terms of rotation group algebra (rather than vector algebra). Euler parameters are used in the rotational dynamics model because they are globally nonsingular, but only the minimal three Euler parameters are used in the error dynamics model because they have no nonlinear mathematical constraints to prevent the realization of linear error dynamics. The control law is singular only when the attitude error angle is exactly pi rad about any eigenaxis, and a simple intuitive modification at the singularity allows the control law to be used globally. The forced error dynamics are nonlinear but stable. Numerical simulation tests show that the control law performs robustly for both initial attitude acquisition and attitude control.
Influencing physiotherapy student attitudes toward exercise for adolescents with Down syndrome.
Shields, Nora; Bruder, Andrea; Taylor, Nicholas; Angelo, Tom
2011-01-01
Negative attitudes of physiotherapists may prevent them from implementing exercise as an intervention among people with disabilities. The aim of this study was to examine whether physiotherapy student attitudes towards the barriers to exercise for adolescents with Down syndrome changed as a result of participating in a 10-week exercise programme. Data were collected as part of a randomised controlled trial. Twenty physiotherapy students (2 men, 18 women; mean age 19.5±1.3 years) volunteered to act as mentors. Each mentor was matched with an adolescent with Down syndrome from the same metropolitan suburb, who had been randomly allocated to either the intervention or the control group. The 10 adolescents and students in the intervention group all completed a 10-week, twice a week progressive resistance exercise training programme. The 10 adolescents and students in the control group continued with their usual activities. The students completed the 18-item Exercise Barriers Scale at baseline and after 10 weeks. There was a positive change in attitudes, significant at the p <0.05 level, favouring the intervention group on 9 of the 18 items on the Exercise Barriers Scale. After engagement in a 10-week exercise programme with an adolescent with Down syndrome, physiotherapy students identified fewer barriers that would prevent adolescents with Down syndrome from exercising. Results indicate that contact with adolescents with Down syndrome during clinical placement can positively influence attitudes towards exercise for people with Down syndrome among physiotherapy students.
Chen, Shiue; Walsh, Sandra M
2009-04-01
Nursing students worldwide have little interest in caring for a growing elder population. The purpose of this study, based on self-transcendence theory, was to test the effectiveness of a creative-bonding intervention (CBI) to promote self-transcendence and positive attitudes towards elders in Taiwanese nursing students. A quasi-experimental design was used to compare a CBI group (n = 100) with a friendly visit (FV) control group (n = 94). ANCOVA results indicated that after the intervention, the CBI group had significantly more positive attitudes towards elders than the FV group. Nursing school faculty may want to promote art-making activities between students and elders to foster students' interest in elder care.
Flight Dynamics Analysis Branch End of Fiscal Year 2002 Report
NASA Technical Reports Server (NTRS)
Mangus, David (Editor); Mendelsohn, Chad (Editor); Starin, Scott (Editor); Stengle, Tom (Editor); Truong, Son (Editor)
2002-01-01
This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 572, in support of flight projects and technology development initiatives in Fiscal Year (FY) 2002. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics including navigation, spacecraft trajectory design, attitude analysis, attitude determination and attitude control. The FDAB currently provides support for missions and technology development projects involving NASA, government, university, and private industry.
Granero Lucchetti, Alessandra Lamas; Ezequiel, Oscarina da Silva; Oliveira, Isabella Noceli de; Moreira-Almeida, Alexander; Lucchetti, Giancarlo
2018-01-21
The present study aims to investigate the effect of two educational strategies to teach geriatrics (flipped classroom-FL and traditional lectures-TR) in relation to a control group (no intervention) on students' competences. An intervention study was conducted during the third year of medicine. Two different educational strategies (flipped classroom and traditional lectures) were incorporated into a theoretical-practical discipline of geriatrics. Students were evaluated about their attitudes towards older persons (Maxwell-Sullivan, UCLA geriatric attitudes), empathy (Maxwell-Sullivan), knowledge (Palmore and cognitive knowledge), skills (standardized patient assessment), and satisfaction with the activities. A total of 243 students were assessed. The FL group demonstrated greater gains in knowledge among students and improved attitude compared to the TR. We found no differences in the skills using a standardized patient. In addition, students exposed to FL felt more prepared to treat older people, believed they had more knowledge, were more satisfied, and evaluated the discipline's format better in relation to the traditional group. Strategies in teaching geriatrics can impact students' knowledge, attitudes, and satisfaction with the course. We found that the way this teaching is delivered can influence students' learning, since there were differences between active and traditional strategies.
A Situation-specific Theory of Midlife Women's Attitudes toward Physical Activity (MAPA)
Im, Eun-Ok; Stuifbergen, Alexa K.; Walker, Lorraine
2010-01-01
This paper presents a situation specific theory—the Midlife Women's Attitudes toward Physical Activity (MAPA) theory—that explains how women's attitudes toward physical activity influence their participation in physical activity. Using the integrative approach of Im, the theory was developed based on the Attitude, Social Influence, and Self Efficacy Model, a review of the related literature, and a study of women's attitudes toward physical activity. As a situation-specific theory, the MAPA theory can be easily linked to nursing practice and research projects related to physical activity in midlife women, especially interventions aimed at increasing midlife women's participation in physical activity. PMID:20113755
Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.
Huo, Mingying; Zhao, Jun; Xie, Shaobiao; Qi, Naiming
2015-01-01
The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail.
Coupled Attitude-Orbit Dynamics and Control for an Electric Sail in a Heliocentric Transfer Mission
Huo, Mingying; Zhao, Jun; Xie, Shaobiao; Qi, Naiming
2015-01-01
The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail. PMID:25950179
NASA Astrophysics Data System (ADS)
Hendrix, Rebecca; Eick, Charles; Shannon, David
2012-11-01
Creative drama activities designed to help children learn difficult science concepts were integrated into an inquiry-based elementary science program. Children (n = 38) in an upper elementary enrichment program at one primary school were the participants in this action research. The teacher-researcher taught students the Full Option Science System™ (FOSS) modules of sound (fourth grade) and solar energy (fifth grade) with the integration of creative drama activities in treatment classes. A 2 × 2 × (2) Mixed ANOVA was used to examine differences in the learning outcomes and attitudes toward science between groups (drama and non-drama) and grade levels (4th and 5th grades) over time (pre/post). Learning was measured using the tests included with the FOSS modules. A shortened version of the Three Dimension Elementary Science Attitude Survey measured attitudes toward science. Students in the drama treatment group had significantly higher learning gains ( F = 160.2, p < 0.001) than students in the non-drama control group with students in grade four reporting significantly greater learning outcomes ( F = 14.3, p < 0.001) than grade five. There was a significantly statistical decrease in student attitudes toward science ( F = 7.5, p < 0.01), though a small change. Creative drama was an effective strategy to increase science conceptual learning in this group of diverse elementary enrichment students when used as an active extension to the pre-existing inquiry-based science curriculum.
High Accuracy Attitude Control of a Spacecraft Using Feedback Linearization
1992-05-01
High Accuracy Attitude Control of a Spacecraft Using Feedback Linearization A Thesis Presented by Louis Joseph PoehIman, Captain, USAF B.S., U.S. Air...High Accuracy Attitude Control of a Spacecraft Using Feedback Linearization by Louis Joseph Poehlman, Captain, USAF Submitted to the Department of...31 2-4 Attitude Determination and Control System Architecture ................. 33 3-1 Exact Linearization Using Nonlinear Feedback
ERIC Educational Resources Information Center
Oudekerk, Barbara A.; Allen, Joseph P.; Hafen, Christopher A.; Hessel, Elenda T.; Szwedo, David E.; Spilker, Ann
2014-01-01
Maternal and paternal psychological control, peer attitudes, and the interaction of psychological control and peer attitudes at age 13 were examined as predictors of risky sexual behavior before age 16 in a community sample of 181 youth followed from age 13 to 16. Maternal psychological control moderated the link between peer attitudes and sexual…
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Mission Specialists Tom Jones and Robert Curbeam test tools that will be used during extravehicular activities (EVA) on their mission. Scheduled for launch Jan. 18, 2001, STS-98 will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Mission Specialists Tom Jones and Robert Curbeam test tools that will be used during extravehicular activities (EVA) on their mission. Scheduled for launch Jan. 18, 2001, STS-98 will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
Oudekerk, Barbara A; Allen, Joseph P; Hafen, Christopher A; Hessel, Elenda T; Szwedo, David E; Spilker, Ann
2014-05-01
Maternal and paternal psychological control, peer attitudes, and the interaction of psychological control and peer attitudes at age 13 were examined as predictors of risky sexual behavior before age 16 in a community sample of 181 youth followed from age 13 to 16. Maternal psychological control moderated the link between peer attitudes and sexual behavior. Peer acceptance of early sex predicted greater risky sexual behaviors, but only for teens whose mothers engaged in high levels of psychological control. Paternal psychological control demonstrated the same moderating effect for girls; for boys, however, high levels of paternal control predicted risky sex regardless of peer attitudes. Results are consistent with the theory that peer influences do not replace parental influences with regard to adolescent sexual behavior; rather, parental practices continue to serve an important role either directly forecasting sexual behavior or moderating the link between peer attitudes and sexual behavior.
Oudekerk, Barbara A.; Allen, Joseph P.; Hafen, Christopher A.; Hessel, Elenda T.; Szwedo, David E.; Spilker, Ann
2013-01-01
Maternal and paternal psychological control, peer attitudes, and the interaction of psychological control and peer attitudes at age 13 were examined as predictors of risky sexual behavior before age 16 in a community sample of 181 youth followed from age 13 to 16. Maternal psychological control moderated the link between peer attitudes and sexual behavior. Peer acceptance of early sex predicted greater risky sexual behaviors, but only for teens whose mothers engaged in high levels of psychological control. Paternal psychological control demonstrated the same moderating effect for girls; for boys, however, high levels of paternal control predicted risky sex regardless of peer attitudes. Results are consistent with the theory that peer influences do not replace parental influences with regard to adolescent sexual behavior; rather, parental practices continue to serve an important role either directly forecasting sexual behavior or moderating the link between peer attitudes and sexual behavior. PMID:25328265
Event-triggered attitude control of spacecraft
NASA Astrophysics Data System (ADS)
Wu, Baolin; Shen, Qiang; Cao, Xibin
2018-02-01
The problem of spacecraft attitude stabilization control system with limited communication and external disturbances is investigated based on an event-triggered control scheme. In the proposed scheme, information of attitude and control torque only need to be transmitted at some discrete triggered times when a defined measurement error exceeds a state-dependent threshold. The proposed control scheme not only guarantees that spacecraft attitude control errors converge toward a small invariant set containing the origin, but also ensures that there is no accumulation of triggering instants. The performance of the proposed control scheme is demonstrated through numerical simulation.
Adaptive mass expulsion attitude control system
NASA Technical Reports Server (NTRS)
Rodden, John J. (Inventor); Stevens, Homer D. (Inventor); Carrou, Stephane (Inventor)
2001-01-01
An attitude control system and method operative with a thruster controls the attitude of a vehicle carrying the thruster, wherein the thruster has a valve enabling the formation of pulses of expelled gas from a source of compressed gas. Data of the attitude of the vehicle is gathered, wherein the vehicle is located within a force field tending to orient the vehicle in a first attitude different from a desired attitude. The attitude data is evaluated to determine a pattern of values of attitude of the vehicle in response to the gas pulses of the thruster and in response to the force field. The system and the method maintain the attitude within a predetermined band of values of attitude which includes the desired attitude. Computation circuitry establishes an optimal duration of each of the gas pulses based on the pattern of values of attitude, the optimal duration providing for a minimal number of opening and closure operations of the valve. The thruster is operated to provide gas pulses having the optimal duration.
The big picture: how social work can effectively utilize photographs.
Marshall, Heather L; Craun, Sarah W; Theriot, Matthew T
2009-10-01
Social work has struggled with image problems and misperceptions of the profession and the types of services it provides. Photography is a medium that has been used effectively by other professions to change attitudes and perceptions. The present study examined the potential of photographs to change the image of available social services--namely, an adult day care program. Participants were divided into two groups: (1) a control group that only completed a survey on attitudes about adult day care services and (2) an experimental group that viewed photographs showing positive images of clients engaged in program activities before taking the survey. A multivariate regression demonstrated that those who saw the photographs before taking the survey had more positive attitudes about adult day care services. In fact, the variable representing the presentation of the photographs had the strongest effect on attitudes. Such findings suggest that photography is a potentially powerful tool to promote positive attitudes about social services programs. The implications of these results are discussed.
Distributed attitude synchronization of formation flying via consensus-based virtual structure
NASA Astrophysics Data System (ADS)
Cong, Bing-Long; Liu, Xiang-Dong; Chen, Zhen
2011-06-01
This paper presents a general framework for synchronized multiple spacecraft rotations via consensus-based virtual structure. In this framework, attitude control systems for formation spacecrafts and virtual structure are designed separately. Both parametric uncertainty and external disturbance are taken into account. A time-varying sliding mode control (TVSMC) algorithm is designed to improve the robustness of the actual attitude control system. As for the virtual attitude control system, a behavioral consensus algorithm is presented to accomplish the attitude maneuver of the entire formation and guarantee a consistent attitude among the local virtual structure counterparts during the attitude maneuver. A multiple virtual sub-structures (MVSSs) system is introduced to enhance current virtual structure scheme when large amounts of spacecrafts are involved in the formation. The attitude of spacecraft is represented by modified Rodrigues parameter (MRP) for its non-redundancy. Finally, a numerical simulation with three synchronization situations is employed to illustrate the effectiveness of the proposed strategy.
Bonfils, Kelsey A; Firmin, Ruth L; Salyers, Michelle P; Wright, Eric R
2015-09-01
Limited research has focused on sexuality for those diagnosed with a severe mental illness. We aimed to extend existing work by exploring relationships between mastery (perception of control of one's life and future), sexual self-esteem (perceptions of one's capacity to engage in healthy sexual behavior), sexual attitudes (permissive ideas about sexuality), and perceived importance of relationships/sexuality and number of sexual partners. A secondary analysis of survey data from adult participants living with a severe mental illness (N = 401) in the Indiana Mental Health Services and HIV-Risk Study (Perry & Wright, 2006) was conducted. Analysis of covariance (controlling for marital status) compared those with 0 partners, 1 partner, or multiple partners over the past 3 months on the dependent variables of mastery, sexual self-esteem, sexual attitudes, and perceived importance. Participants with more permissive attitudes, greater perceived importance, and higher mastery were more likely to be sexually active with multiple partners. Self-esteem did not differentiate groups. Given the key role of sexual satisfaction in quality of life and the high rates of sexual risk behavior in this population, it is important that clinicians systematically assess mastery, perceived importance, and attitudes about sexuality when working with consumers diagnosed with a severe mental illness. Individually tailoring existing interventions on the basis of consumers' levels of mastery, related to self-efficacy for implementing changes in life, could improve long-term outcomes for these programs. Future research should examine other constructs that may account for more variance in sexual activity, such as perceptions of risk, intentions for sexual safety, or romantic relationship functioning. (c) 2015 APA, all rights reserved).
Bonfils, Kelsey A.; Firmin, Ruth L.; Salyers, Michelle P.; Wright, Eric R.
2015-01-01
Objective Limited research has focused on sexuality for those diagnosed with a severe mental illness. We aimed to extend existing work by exploring relationships between mastery (perception of control of one's life and future), sexual self-esteem (perceptions of one's capacity to engage in healthy sexual behavior), sexual attitudes (permissive ideas about sexuality), and perceived importance of relationships/sexuality and number of sexual partners. Methods A secondary analysis of survey data from adult participants living with a severe mental illness (N=401) in the Indiana Mental Health Services and HIV-Risk Study (Perry & Wright, 2006) was conducted. Analysis of covariance (controlling for marital status) compared those with zero partners, one partner, or multiple partners over the past three months on the dependent variables of mastery, sexual self-esteem, sexual attitudes, and perceived importance. Results Participants with more permissive attitudes, greater perceived importance, and higher mastery were more likely to be sexually active with multiple partners. Self-esteem did not differentiate groups. Conclusions and Implications for Practice Given the key role of sexual satisfaction in quality of life and the high rates of sexual risk behavior in this population, it is important that clinicians systematically assess mastery, perceived importance, and attitudes about sexuality when working with consumers diagnosed with a severe mental illness. Individually tailoring existing interventions based on consumers' levels of mastery, related to self-efficacy for implementing changes in life, could improve long-term outcomes for these programs. Future research should examine other constructs that may account for more variance in sexual activity, such as perceptions of risk, intentions for sexual safety, or romantic relationship functioning. PMID:25664756
Lo, C C; Globetti, G
1995-01-01
The purpose of this study was to examine how selected internal and external control variables influence lifetime use, frequency of use, and cessation of use of marijuana. The internal control factor, comprising the variables 1) perceived risk of marijuana use and 2) attitudes toward prohibition of marijuana use, refers to a built-in personal tendency toward conventionality. The external control factor refers to social-environmental forces which discourage marijuana use. External control is indicated by factors including the number of extra-curricular activities in which an individual is involved; place of residence; the availability of marijuana; peer attitudes toward marijuana use; the number of an individual's friends who use marijuana; and the number of occasions on which an individual has observed others using marijuana. The study's results show that both internal and external control factors are significant predictors of the frequency of marijuana use. The external control factor, however, plays a more important role in explaining lifetime marijuana use and cessation of marijuana use.
Holahan, Carole K; Holahan, Charles J; Li, Xiaoyin; Chen, Yen T
2017-02-01
Physical activity carries immediate and long-term benefits for middle-aged and older women; however, physical activity decreases in adulthood and aging in women. In this study, the authors investigate the relation of health behaviors, health attitudes, and health appraisals to leisure-time physical activity among middle-aged and older women in a cross-sectional analysis of the second wave of the Study of Midlife Development in the United States (MIDUS2) conducted during the period from 2004 to 2006. The sample consisted of 829 women, ranging in age from 40 to 75 years of age (Mean = 56 years). In multiple logistic regression analyses, controlling for socio-demographic factors and functional restrictions, most of the psychosocial variables examined showed unique associations with physical activity, including health behaviors of having a routine checkup and not smoking, health attitudes involving commitment to health and valuing physical fitness and strength, and the health appraisal that one's health is better compared to others of the same age. Older women (aged 61-75 years) were less active, but reported greater health commitment than middle-aged women (aged 40-60 years). Neither health commitment nor any other psychosocial variable interacted with age in relation to physical activity. Understanding characteristics of middle-aged and older women who are physically active is essential in tailoring interventions to this population.
Solar Dynamics Observatory Launch and Commissioning
NASA Technical Reports Server (NTRS)
O'Donnell, James R., Jr.; Kristin, D.; Bourkland, L.; Hsu, Oscar C.; Liu, Kuo-Chia; Mason, Paul A. C.; Morgenstern, Wendy M.; Russo, Angela M.; Starin, Scott R.; Vess, Melissa F.
2011-01-01
The Solar Dynamics Observatory (SDO) was launched on February 11, 2010. Over the next three months, the spacecraft was raised from its launch orbit into its final geosynchronous orbit and its systems and instruments were tested and calibrated in preparation for its desired ten year science mission studying the Sun. A great deal of activity during this time involved the spacecraft attitude control system (ACS); testing control modes, calibrating sensors and actuators, and using the ACS to help commission the spacecraft instruments and to control the propulsion system as the spacecraft was maneuvered into its final orbit. This paper will discuss the chronology of the SDO launch and commissioning, showing the ACS analysis work performed to diagnose propellant slosh transient and attitude oscillation anomalies that were seen during commissioning, and to determine how to overcome them. The simulations and tests devised to demonstrate correct operation of all onboard ACS modes and the activities in support of instrument calibration will be discussed and the final maneuver plan performed to bring SDO on station will be shown. In addition to detailing these commissioning and anomaly resolution activities, the unique set of tests performed to characterize SDO's on-orbit jitter performance will be discussed.
Energy management and attitude control for spacecraft
NASA Astrophysics Data System (ADS)
Costic, Bret Thomas
2001-07-01
This PhD dissertation describes the design and implementation of various control strategies centered around spacecraft applications: (i) an attitude control system for spacecraft, (ii) flywheels used for combined attitude and energy tracking, and (iii) an adaptive autobalancing control algorithm. The theory found in each of these sections is demonstrated through simulation or experimental results. An introduction to each of these three primary chapters can be found in chapter one. The main problem addressed in the second chapter is the quaternion-based, attitude tracking control of rigid spacecraft without angular velocity measurements and in the presence of an unknown inertia matrix. As a stepping-stone, an adaptive, full-state feedback controller that compensates for parametric uncertainty while ensuring asymptotic attitude tracking errors is designed. The adaptive, full-state feedback controller is then redesigned such that the need for angular velocity measurements is eliminated. The proposed adaptive, output feedback controller ensures asymptotic attitude tracking. This work uses a four-parameter representation of the spacecraft attitude that does not exhibit singular orientations as in the case of the previous three-parameter representation-based results. To the best of my knowledge, this represents the first solution to the adaptive, output feedback, attitude tracking control problem for the quaternion representation. Simulation results are included to illustrate the performance of the proposed output feedback control strategy. The third chapter is devoted to the use of multiple flywheels that integrate the energy storage and attitude control functions in space vehicles. This concept, which is referred to as an Integrated Energy Management and Attitude Control (IEMAC) system, reduces the space vehicle bus mass, volume, cost, and maintenance requirements while maintaining or improving the space vehicle performance. To this end, two nonlinear IEMAC strategies (model-based and adaptive) that simultaneously track a desired attitude trajectory and desired energy/power profile are presented. Both strategies ensure asymptotic tracking while the adaptive controller compensates for uncertain spacecraft inertia. In the final chapter, a control strategy is designed for a rotating, unbalanced disk. The control strategy, which is composed of a control torque and two control forces, regulates the disk displacement and ensures angular velocity tracking. The controller uses a desired compensation adaptation law and a gain adjusted forgetting factor to achieve exponential stability despite the lack of knowledge of the imbalance-related parameters, provided a mild persistency of excitation condition is satisfied.
Attributions and Attitudes of Mothers and Fathers in the United States.
Lansford, Jennifer E; Bornstein, Marc H; Dodge, Kenneth A; Skinner, Ann T; Putnick, Diane L; Deater-Deckard, Kirby
2011-01-01
OBJECTIVE.: The present study examined mean level similarities and differences as well as correlations between U.S. mothers' and fathers' attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. DESIGN.: Interviews were conducted with both mothers and fathers in 139 European American, Latin American, and African American families. RESULTS.: Interactions between parent gender and ethnicity emerged for adult-controlled failure and perceived control over failure. Fathers reported higher adult-controlled failure and child-controlled failure attributions than did mothers, whereas mothers reported attitudes that were more progressive and modern than did fathers; these differences remained significant after controlling for parents' age, education, and possible social desirability bias. Ethnic differences emerged for five of the seven attributions and attitudes examined; four remained significant after controlling for parents' age, education, and possible social desirability bias. Medium effect sizes were found for concordance between parents in the same family for attributions regarding uncontrollable success, child-controlled failure, progressive attitudes, authoritarian attitudes, and modernity of attitudes after controlling for parents' age, education, and possible social desirability bias. CONCLUSIONS.: This work elucidates ways that parent gender and ethnicity relate to attributions regarding U.S. parents' successes and failures in caregiving situations and to their progressive versus authoritarian parenting attitudes.
Attributions and Attitudes of Mothers and Fathers in the United States
Lansford, Jennifer E.; Bornstein, Marc H.; Dodge, Kenneth A.; Skinner, Ann T.; Putnick, Diane L.; Deater-Deckard, Kirby
2011-01-01
SYNOPSIS Objective. The present study examined mean level similarities and differences as well as correlations between U.S. mothers’ and fathers’ attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. Design. Interviews were conducted with both mothers and fathers in 139 European American, Latin American, and African American families. Results. Interactions between parent gender and ethnicity emerged for adult-controlled failure and perceived control over failure. Fathers reported higher adult-controlled failure and child-controlled failure attributions than did mothers, whereas mothers reported attitudes that were more progressive and modern than did fathers; these differences remained significant after controlling for parents’ age, education, and possible social desirability bias. Ethnic differences emerged for five of the seven attributions and attitudes examined; four remained significant after controlling for parents’ age, education, and possible social desirability bias. Medium effect sizes were found for concordance between parents in the same family for attributions regarding uncontrollable success, child-controlled failure, progressive attitudes, authoritarian attitudes, and modernity of attitudes after controlling for parents’ age, education, and possible social desirability bias. Conclusions. This work elucidates ways that parent gender and ethnicity relate to attributions regarding U.S. parents’ successes and failures in caregiving situations and to their progressive versus authoritarian parenting attitudes. PMID:21822402
A situation-specific theory of Midlife Women's Attitudes Toward Physical Activity (MAPA).
Im, Eun-Ok; Stuifbergen, Alexa K; Walker, Lorraine
2010-01-01
This paper presents a situation specific theory-the Midlife Women's Attitudes Toward Physical Activity (MAPA) theory-that explains how women's attitudes toward physical activity influence their participation in physical activity. Using the integrative approach of Im, the theory was developed based on the Attitude, Social Influence, and Self Efficacy Model; a review of the related literature; and a study of women's attitudes toward physical activity. As a situation-specific theory, the MAPA theory can be linked easily to nursing practice and research projects related to physical activity in midlife women, especially interventions aimed at increasing midlife women's participation in physical activity. Copyright 2010 Mosby, Inc. All rights reserved.
Croker, Helen; Lucas, Rebecca; Wardle, Jane
2012-06-06
Social marketing campaigns offer a promising approach to the prevention of childhood obesity. Change4Life (C4L) is a national obesity prevention campaign in England. It included mass media coverage aiming to reframe obesity into a health issue relevant to all and provided the opportunity for parents to complete a brief questionnaire ('How are the Kids') and receive personalised feedback about their children's eating and activity. Print and online C4L resources were available with guidance about healthy eating and physical activity. The study aims were to examine the impact of personalised feedback and print material from the C4L campaign on parents' attitudes and behaviours about their children's eating and activity in a community-based cluster-randomised controlled trial. Parents of 5-11 year old children were recruited from 40 primary schools across England. Schools were randomised to intervention or control ('usual care'). Basic demographic data and brief information about their attitudes to their children's health were collected. Families in intervention schools were mailed the C4L print materials and the 'How are the Kids' questionnaire; those returning the questionnaire were sent personalised feedback and others received generic materials. Outcomes included awareness of C4L, attitudes to the behaviours recommended in C4L, parenting behaviours (monitoring and modelling), and child health behaviours (diet, physical activity and television viewing). Follow-up data were collected from parents by postal questionnaire after six months. Qualitative interviews were carried out with a subset of parents (n = 12). 3,774 families completed baseline questionnaires and follow-up data were obtained from 1,419 families (37.6%). Awareness was high in both groups at baseline (75%), but increased significantly in the intervention group by follow-up (96% vs. 87%). Few parents (5.2% of the intervention group) returned the questionnaire to get personalised feedback. There were few significant group differences in parental attitudes or parenting and child health behaviours at follow-up. Physical activity was rated as less important in the intervention group, but a significant group-by-socioeconomic status (SES) interaction indicated that this effect was confined to higher SES families. Similar interactions were also seen for physical activity monitoring and child television time; with adverse effects in higher SES families and no change in the lower SES families. Effects were little better in families that completed the questionnaire and received personalised feedback. At interview, acceptability of the intervention was modest, although higher in lower SES families. The C4L campaign materials achieved increases in awareness of the campaign, but in this sample had little impact on attitudes or behaviour. Low engagement with the intervention appeared a key issue. Current Controlled Trials ISRCTN00791709.
Wang, Lijuan; Wang, Lin
2015-01-01
The primary objective of this study was to use the theory of planned behavior (TPB) to examine the association between TPB variables and the moderate-to-vigorous physical activity (MVPA) of children in Shanghai, China. Gender differences were also explored. The participants were 353 children (180 boys and 173 girls) aged 9 to 13 years from three primary schools in Shanghai. Accelerometers were used to measure the MVPA duration of the children. Questionnaires that focused on attitude, subjective norms, and perceived behavioral control (PBC) related to MVPA engagement were completed by the participants. Regression analyses revealed that intention, and not PBC, accounted for 9% of the variance in MVPA. Meanwhile, attitude and PBC explained 33% of the variance in intentions to engage in MVPA. In terms of gender differences, TPB performed better in the physical activity (PA) domain for boys than for girls. Furthermore, attitude and PBC were significantly associated with intention among boys, whereas only PBC was significantly related to intention among girls. Practitioners should consider tailoring intervention to address gender differences to increase leisure-time PA participation of children.
SSS-A attitude control prelaunch analysis and operations plan
NASA Technical Reports Server (NTRS)
Werking, R. D.; Beck, J.; Gardner, D.; Moyer, P.; Plett, M.
1971-01-01
A description of the attitude control support being supplied by the Mission and Data Operations Directorate is presented. Descriptions of the computer programs being used to support the mission for attitude determination, prediction, control, and definitive attitude processing are included. In addition, descriptions of the operating procedures which will be used to accomplish mission objectives are provided.
Young adults' media use and attitudes toward interpersonal and institutional forms of aggression.
Brady, Sonya S
2007-01-01
Links between media violence exposure and favorable attitudes toward interpersonal violence are well established, but few studies have examined whether associations extend to include favorable attitudes toward institutional forms of aggression. Studies on this topic have not assessed multiple forms of media use and statistically controlled for individual characteristics likely to influence attitudes beyond sociodemographic information. In this study, undergraduate students (N=319) aged 18-20 years (56% male) completed a survey assessing media use (number of hours per week spent playing videogames, watching movies/TV shows, watching TV sports) and attitudes toward interpersonal violence, punitive criminal justice policies, and different types of military activities (preparedness/defense and aggressive intervention). Greater number of hours spent watching TV contact sports was associated with more favorable attitudes toward military preparedness/defense, aggressive military intervention, and punitive criminal justice policies among men independently of parental education, lifetime violence exposure within the home and community, aggressive personality, and constrained problem solving style. Greater number of hours spent watching violent movies/TV was associated with more favorable attitudes toward military preparedness/defense among men and with more favorable attitudes toward interpersonal violence and punitive criminal justice policies among women, but these associations became non-significant when adjusting for covariates. 2007 Wiley-Liss, Inc.
NASA Technical Reports Server (NTRS)
Boland, J. S., III
1973-01-01
The conventional six-engine reaction control jet relay attitude control law with deadband is shown to be a good linear approximation to a weighted time-fuel optimal control law. Techniques for evaluating the value of the relative weighting between time and fuel for a particular relay control law is studied along with techniques to interrelate other parameters for the two control laws. Vehicle attitude control laws employing control moment gyros are then investigated. Steering laws obtained from the expression for the reaction torque of the gyro configuration are compared to a total optimal attitude control law that is derived from optimal linear regulator theory. This total optimal attitude control law has computational disadvantages in the solving of the matrix Riccati equation. Several computational algorithms for solving the matrix Riccati equation are investigated with respect to accuracy, computational storage requirements, and computational speed.
Pardo, Raúl H; Carvajal, Alexander; Ferro, Cristina; Davies, Clive R
2006-10-01
Householder vector control measures can be encouraged by health promotion campaigns which take into account peoples' attitudes and focus on key gaps in knowledge. To describe household sandfly control practices in an endemic area of cutaneous leishmaniasis in the department of Huila, Colombia, and determine how these are influenced by attitudes, knowledge and socioeconomic status. A household questionnaire was applied to collect information on: demography, socioeconomic status, knowledge of cutaneous leishmaniasis and of sandflies and their role in transmission, and the control activities practiced. Indoor sandfly abundance was estimated by light trap collections. Amongst 249 interviewees, 86% knew about cutaneous leishmaniasis and 98% sand flies. 35% of interviewees who knew about cutaneous leishmaniasis practiced measures with the purpose of its control. This practice was higher amongst the 32% who knew that sand flies transmit cutaneous leishmaniasis. However, 82% of interviewees practiced sand fly control measures, and these were significantly associated with high sand fly abundance. Measures included smoke, bednets, and house spraying with insecticide or non-insecticidal substances. Householders using the high cost measures (bednets and insecticide) had the highest economic status. Health education programmes should note that sand fly nuisance can initiate control measures, but that knowledge of the role of sand flies in transmission could enhance activities. The socioeconomic findings indicate that targeted bednet subsidies could reduce inequities in health status amongst cutaneous leishmaniasis endemic communities.
ERIC Educational Resources Information Center
McLachlan, Sarah; Hagger, Martin S.
2010-01-01
This study aimed to explore relations between chronically accessible outcomes in physical activity and scaled measures of motivational orientations from a self-determination perspective. Methods from construct and attitude accessibility research and the Levesque and Pelletier (2003) study were used to identify participants' chronically accessible…
Modular design attitude control system
NASA Technical Reports Server (NTRS)
Chichester, F. D.
1982-01-01
A hybrid multilevel linear quadratic regulator (ML-LQR) approach was developed and applied to the attitude control of models of the rotational dynamics of a prototype flexible spacecraft and of a typical space platform. Three axis rigid body flexible suspension models were developed for both the spacecraft and the space platform utilizing augmented body methods. Models of the spacecraft with hybrid ML-LQR attitude control and with LQR attitude control were simulated and their response with the two different types of control were compared.
NASA Astrophysics Data System (ADS)
Keum, Jung-Hoon; Ra, Sung-Woong
2009-12-01
Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.
A Comparison of Upper Elementary School Children's Attitudes toward Physical Activity.
ERIC Educational Resources Information Center
Folsom-Meek, Sherry L.
This study was conducted to compare upper elementary school children's attitudes toward physical activity, by grade level and gender across six attitude scale subdomains in order to assist physical education teachers in planning programs designed to foster positive attitudes toward physical activity. Subjects (N=429) were 243 girls and 186 boys in…
He, ZeFang; Zhao, Long
2014-01-01
An attitude control strategy based on Ziegler-Nichols rules for tuning PD (proportional-derivative) parameters of quadrotor helicopters is presented to solve the problem that quadrotor tends to be instable. This problem is caused by the narrow definition domain of attitude angles of quadrotor helicopters. The proposed controller is nonlinear and consists of a linear part and a nonlinear part. The linear part is a PD controller with PD parameters tuned by Ziegler-Nichols rules and acts on the quadrotor decoupled linear system after feedback linearization; the nonlinear part is a feedback linearization item which converts a nonlinear system into a linear system. It can be seen from the simulation results that the attitude controller proposed in this paper is highly robust, and its control effect is better than the other two nonlinear controllers. The nonlinear parts of the other two nonlinear controllers are the same as the attitude controller proposed in this paper. The linear part involves a PID (proportional-integral-derivative) controller with the PID controller parameters tuned by Ziegler-Nichols rules and a PD controller with the PD controller parameters tuned by GA (genetic algorithms). Moreover, this attitude controller is simple and easy to implement.
Yusuf, Huda; Kolliakou, Anna; Ntouva, Antiopi; Murphy, Marie; Newton, Tim; Tsakos, Georgios; Watt, Richard G
2016-02-08
To explore the factors predicting preventive behaviours among NHS dentists in Camden, Islington and Haringey in London, using constructs from the Theory of Planned Behaviour. A cross-sectional survey of NHS dentists working in North Central London was conducted. A self-completed questionnaire based on the theoretical framework of the Theory of Planned Behaviour was developed. It assessed dentists' attitudes, current preventive activities, subjective norms and perceived behavioural control in delivering preventive care. In model 1, logistic regression was conducted to assess the relationship between a range of preventive behaviours (diet, smoking and alcohol) and the three TPB constructs attitude, subjective norms and perceived behavioural control. Model 2 was adjusted for intention. Overall, 164 questionnaires were returned (response rate: 55.0%). Dentists' attitudes were important predictors of preventive behaviours among a sample of dentists in relation to asking and providing diet, alcohol and tobacco advice. A dentist was 3.73 times (95 % CI: 1.70, 8.18) more likely ask about a patient's diet, if they had a positive attitude towards prevention, when adjusted for age, sex and intention. A similar pattern emerged for alcohol advice (OR 2.35, 95 % CI 1.12, 4.96). Dentists who had a positive attitude were also 2.59 times more likely to provide smoking cessation advice. The findings of this study have demonstrated that dentists' attitudes are important predictors of preventive behaviours in relation to delivery of diet, smoking and alcohol advice.
Gao, Yuan; Feng, Yuchao; Wang, Min; Su, Yiwei; Li, Yanhua; Wang, Zhi; Tang, Shihao
2015-04-01
To develop the knowledge, attitude and practice questionnaire on the prevention and control of occupational diseases for occupational groups, and to provide a convenient and effective tool for the survey of knowledge, attitude, and behavior on the prevention and control of occupational diseases in occupational groups and the evaluation of intervention effect. The initial questionnaire which was evaluated by the experts was used to carry out a pre-survey in Guangzhou, China. The survey results were statistically analyzed by t test, identification index method, correlation analysis, and Cronbach's a coefficient method. And then the questionnaire was further modified, and the content of the questionnaire was determined finally. After modification, there were 18 items on knowledge, 16 items on attitude, and 12 items on behavior in the "Knowledge, attitude and practice questionnaire on the prevention and control of occupational diseases for enterprise managers"; there were 19 items on knowledge, 10 items on attitude, and 11 items on behavior in the "Knowledge, attitude and practice questionnaire on the prevention and control of occupational diseases for workers". The knowledge, attitude and practice questionnaire on the prevention and control of occupational diseases for occupational groups is developed successfully, and it is a convenient and effective tool for the survey of knowledge, attitude, and behavior on the prevention and control of occupational diseases in occupational groups and the evaluation of intervention effect.
A movable-mass attitude stabilization system for cable-connected artificial-g space stations
NASA Technical Reports Server (NTRS)
Childs, D. W.; Hardison, T. L.
1974-01-01
The development of an active, momentum-exchange system to be used for attitude stabilization of a class of cable-connected artificial-g space stations is studied. A system which employs a single movable control mass is examined for the control of a space station which has the physical appearance of two cylinders connected axially by cables. The dynamic model for the space station includes its aggregate rigid body rotation and relative torsional rotation between the bodies. A zero torsional stiffness design (one cable) and a maximum torsional stiffness design (eight cables) are examined in various stages of deployment, for selected spin velocities ranging from 4 rpm upwards. A linear, time-invariant, feed-back control system is employed, with gains calculated via a root-specification procedure. The movable mass controller provides critical wobble-damping capability for the crew quarters for all configurations and spin velocity.
Senguttuvan, Umadevi; Whiteman, Shawn D.; Jensen, Alexander C.
2014-01-01
Family relationships are important predictors of adolescents’ diet, physical activity, and health issues including obesity. Despite their prominence in the family, siblings have received little attention on how they may influence these health-related behaviors. Addressing this gap, the present study examined associations between sibling relationship qualities and adolescents’ health attitudes, exercise behaviors, and weight controlling for other family relationship qualities. Participants included one parent and two adolescent siblings (ages 12 to 19) from 326 families. Multilevel models indicated that net of parent-adolescent relationship qualities and adolescents’ personal characteristics, sibling intimacy was related to healthy attitudes and greater exercise behaviors, whereas sibling conflict was associated with increased risk of being overweight. Links between sibling conflict and weight status, however, were further qualified by gender composition of the sibling dyad. Results highlight the significance of sibling relationships in adolescents’ everyday health attitudes and behaviors and implications for intervention efforts are discussed. PMID:24954967
Clusters of midlife women by physical activity and their racial/ethnic differences.
Im, Eun-Ok; Ko, Young; Chee, Eunice; Chee, Wonshik; Mao, Jun James
2017-04-01
The purpose of this study was to identify clusters of midlife women by physical activity and to determine racial/ethnic differences in physical activities in each cluster. This was a secondary analysis of the data from 542 women (157 non-Hispanic [NH] Whites, 127 Hispanics, 135 NH African Americans, and 123 NH Asian) in a larger Internet study on midlife women's attitudes toward physical activity. The instruments included the Barriers to Health Activities Scale, the Physical Activity Assessment Inventory, the Questions on Attitudes toward Physical Activity, Subjective Norm, Perceived Behavioral Control, and Behavioral Intention, and the Kaiser Physical Activity Survey. The data were analyzed using hierarchical cluster analyses, analysis of variance, and multinominal logistic analyses. A three-cluster solution was adopted: cluster 1 (high active living and sports/exercise activity group; 48%), cluster 2 (high household/caregiving and occupational activity group; 27%), and cluster 3 (low active living and sports/exercise activity group; 26%). There were significant racial/ethnic differences in occupational activities of clusters 1 and 3 (all P < 0.01). Compared with cluster 1, cluster 2 tended to have lower family income, less access to health care, higher unemployment, higher perceived barriers scores, and lower social influences scores (all P < 0.01). Compared with cluster 1, cluster 3 tended to have greater obesity, less access to health care, higher perceived barriers scores, more negative attitudes toward physical activity, and lower self-efficacy scores (all P < 0.01). Midlife women's unique patterns of physical activity and their associated factors need to be considered in future intervention development.
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Mission Specialists Tom Jones (second from left) and Robert Curbeam (right) test tools that will be used during extravehicular activities (EVA) on their mission. Scheduled for launch Jan. 18, 2001, STS-98 will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Mission Specialists Tom Jones (second from left) and Robert Curbeam (right) test tools that will be used during extravehicular activities (EVA) on their mission. Scheduled for launch Jan. 18, 2001, STS-98 will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
Integrated Orbit and Attitude Control for a Nanosatellite with Power Constraints
NASA Technical Reports Server (NTRS)
Naasz, Bo; Hall, Christopher; Berry, Matthew; Hy-Young, Kim
2003-01-01
Small satellites tend to be power-limited, so that actuators used to control the orbit and attitude must compete with each other as well as with other subsystems for limited electrical power. The Virginia Tech nanosatellite project, HokieSat, must use its limited power resources to operate pulsed-plasma thrusters for orbit control and magnetic torque coils for attitude control, while also providing power to a GPS receiver, a crosslink transceiver, and other subsystems. The orbit and attitude control strategies were developed independently. The attitude control system is based on an application of Linear Quadratic Regulator (LQR) to an averaged system of equations, whereas the orbit control is based on orbit element feedback. In this paper we describe the strategy for integrating these two control systems and present simulation results to verify the strategy.
Spacecraft Hybrid Control At NASA: A Look Back, Current Initiatives, and Some Future Considerations
NASA Technical Reports Server (NTRS)
Dennehy, Neil
2014-01-01
There is a heightened interest within NASA for the design, development, and flight implementation of mixed actuator hybrid attitude control systems for science spacecraft that have less than three functional reaction wheel actuators. This interest is driven by a number of recent reaction wheels failures on aging, but still scientifically productive, NASA spacecraft. This paper describes the highlights of the first NASA Cross-Center Hybrid Control Workshop that was held in Greenbelt, Maryland in April of 2013 under the sponsorship of the NASA Engineering and Safety Center (NESC). A brief historical summary of NASA's past experiences with spacecraft mixed actuator hybrid attitude control approaches, some of which were implemented on-orbit, will be provided. This paper will also convey some of the lessons learned and best practices captured at that workshop. Some relevant recent and current hybrid control activities will be described with an emphasis on work in support of a repurposed Kepler spacecraft. Specific technical areas for future considerations regarding spacecraft hybrid control will also be identified.
Exposures Associated With Minority High Schoolers’ Predisposition for Health Science
Boekeloo, Bradley; Brooks, Alyssa Todaro; Wang, Min Qi
2016-01-01
Objective To identify modifiable facilitation strategies (exposures) during high school that are associated with motivation for minority youth pursuit of health science. Methods A sample (N = 116) of minority (73% African American/Black, 21% Hispanic/Latino) 12th graders from 6 high schools in a lower socioeconomic area bordering Washington, DC completed a self-administered survey. Path modeling was used to examine whether: 1) exposures: high school science courses, extra-curricular science activities, personal health experiences, and adult encouragement predict Theory of Planned Behavior (TPB) constructs including Attitude, Subjective Norm, and Perceived Behavioral Control, and 2) TPB constructs predict the outcome of Intent to pursue college health science. Results The path model indicated that adult encouragement was associated with Attitude (p < .001), Subjective Norm (p < .001), and Perceived Behavioral Control (p < .001); and personal health experiences were associated with Attitude (p < .001). Attitude and Subjective Norm were associated with Intent (p < .001). Conclusion Motivating minority high schoolers from low socioeconomic areas through adult encouragement and personal health experiences to value health scientists and to perceive that others support their pursuit of health science may be pathways for facilitating their intention to pursue college health science. PMID:28452687
Exposures Associated with Minority High Schoolers' Predisposition for Health Science.
Boekeloo, Bradley O; Todaro Brooks, Alyssa; Qi Wang, Min
2017-03-01
We examined modifiable facilitation strategies (exposures) during high school that are associated with motiva- tion for minority youth pursuit of health science. A sample (N = 116) of minority (73% African-American/Black, 21% Hispanic/Latino) 12th graders from 6 high schools in a lower socioeconomic area bordering Washington, DC completed a self-administered survey. Path modeling was used to examine whether: (1) exposures: high school science courses, extra-curricular science activities, personal health experiences, and adult encouragement predict Theory of Planned Behavior (TPB) constructs including attitude, subjective norm, and perceived behavioral control, and (2) TPB constructs predict the outcome of intent to pursue college health science. The path model indicated that adult encouragement was associated with attitude (p < .01), subjective norm (p < .01), and perceived behavioral control (p < .01); and personal health experiences were associated with attitude (p < .01). Attitude and subjective norm were associated with intent (p < .01). Motivating minority high schoolers from low socioeconomic areas through adult encouragement and personal health experiences to value health scientists and to perceive that others support their pursuit of health science may be pathways for facilitating their intention to pursue college health science.
Boudreau, François; Godin, Gaston
2014-12-01
Most people with type 2 diabetes do not engage in regular leisure-time physical activity. The theory of planned behavior and moral norm construct can enhance our understanding of physical activity intention and behavior among this population. This study aims to identify the determinants of both intention and behavior to participate in regular leisure-time physical activity among individuals with type 2 diabetes who not meet Canada's physical activity guidelines. By using secondary data analysis of a randomized computer-tailored print-based intervention, participants (n = 200) from the province of Quebec (Canada) completed and returned a baseline questionnaire measuring their attitude, perceived behavioral control, and moral norm. One month later, they self-reported their level of leisure-time physical activity. A hierarchical regression equation showed that attitude (beta = 0.10, P < 0.05), perceived behavioral control (beta = 0.37, P < 0.001), and moral norm (beta = 0.45, P < 0.001) were significant determinants of intention, with the final model explaining 63% of the variance. In terms of behavioral prediction, intention (beta = 0.34, P < 0.001) and perceived behavioral control (beta = 0.16, P < 0.05) added 17% to the variance, after controlling the effects of the experimental condition (R (2) = 0.04, P < 0.05) and past participation in leisure-time physical activity (R (2) = 0.22, P < 0.001). The final model explained 43% of the behavioral variance. Finally, the bootstrapping procedure indicated that the influence of moral norm on behavior was mediated by intention and perceived behavioral control. The determinants investigated offered an excellent starting point for designing appropriate counseling messages to promote leisure-time physical activity among individuals with type 2 diabetes.
Precision Attitude Determination System (PADS) design and analysis. Two-axis gimbal star tracker
NASA Technical Reports Server (NTRS)
1973-01-01
Development of the Precision Attitude Determination System (PADS) focused chiefly on the two-axis gimballed star tracker and electronics design improved from that of Precision Pointing Control System (PPCS), and application of the improved tracker for PADS at geosynchronous altitude. System design, system analysis, software design, and hardware design activities are reported. The system design encompasses the PADS configuration, system performance characteristics, component design summaries, and interface considerations. The PADS design and performance analysis includes error analysis, performance analysis via attitude determination simulation, and star tracker servo design analysis. The design of the star tracker and electronics are discussed. Sensor electronics schematics are included. A detailed characterization of the application software algorithms and computer requirements is provided.
Attitude control challenges for earth orbiters of the 1980's
NASA Technical Reports Server (NTRS)
Hibbard, W.
1980-01-01
Experience gained in designing attitude control systems for orbiting spacecraft of the late 1980's is related. Implications for satellite attitude control design of the guidance capabilities, rendezvous and recovery requirements, use of multiple-use spacecraft and the development of large spacecraft associated with the advent of the Space Shuttle are considered. Attention is then given to satellite attitude control requirements posed by the Tracking and Data Relay Satellite System, the Global Positioning System, the NASA End-to-End Data System, and Shuttle-associated subsatellites. The anticipated completion and launch of the Space Telescope, which will provide one of the first experiences with the new generation of attitude control, is also pointed out.
Assessing landowners' attitudes toward wild hogs and support for control options.
Caplenor, Carlotta A; Poudyal, Neelam C; Muller, Lisa I; Yoest, Chuck
2017-10-01
Wild hogs (Sus scrofa) are an invasive species with destructive habits, particularly rooting and wallowing, which can directly impact agricultural crops, pasture land, and water quality. Considering wild hogs are widely dispersed across the landscape, they are extremely difficult to control. Disagreements can arise among different stakeholders over whether and how their populations should be managed. The purpose of this article was to examine Tennessee, United States landowners' attitudes toward wild hogs, to compare acceptability of control methods, and to evaluate factors significantly influencing public support for regulations to control wild hogs. Logistic regression was employed to analyze data collected from a statewide survey of rural landowners in the fall of 2015. Landowners had overwhelmingly negative attitudes towards wild hogs, and were concerned about their impact on the natural environment and rural economy. Although landowners showed support for controlling wild hogs, levels of acceptability for management options varied. Respondents favored active management and supported education and incentive-based control programs to control wild hogs. Cognitive concepts such as social and personal norms and awareness of consequences, as well as demographic characteristics, significantly predicted landowners' support for state regulations to control wild hogs in Tennessee. Findings increase our understanding of the human dimensions of wild hog management and that of other similarly invasive animals, and may guide resource managers in designing effective and socially acceptable management strategies to control wild hog populations in Tennessee and elsewhere. Copyright © 2017 Elsevier Ltd. All rights reserved.
Aşçi, F Hülya; Tüzün, Macide; Koca, Canan
2006-11-01
This study aimed to examine eating attitudes and physical activity level of young women and men university students with regard to social physique anxiety level. 482 university students participated in this study voluntarily. "Eating Attitude Test (EAT-40)", "Social Physique Anxiety Scale" and "Physical Activity Assessment Questionnaire" were used to assess the eating attitude, social physique anxiety and physical activity level of participants, respectively. Women and men participants in this study were assigned to high (HSPA) and low (LSPA) social physique anxiety groups with respect to their median scores. Men had favorable eating attitudes and higher physical activity level than women. In addition, participants in the HSPA group had unfavorable eating attitudes and higher physical activity MET values than participants in the LSPA group. On the other hand, groupxgender interaction was only significant for the eating attitudes scores but, not for physical activity level. Women in the HSPA group scored higher on the EAT-40 than men in HSPA and women and men in the LSPA groups.
Hewson, D J; McNair, P J; Marshall, R N
2000-08-01
Flying an aircraft requires a considerable degree of coordination, particularly during aerobatic activities such as rolls, loops and turns. Only one previous study has examined the magnitude of muscle activity required to fly an aircraft, and that was restricted to takeoff and landing maneuvers. The aim of this study was to examine the phasing of muscle activation and control forces of novice and experienced pilots during more complex simulated flight maneuvers. There were 12 experienced and 9 novice pilots who were tested on an Aermacchi flight simulator while performing a randomized set of rolling, looping, and turning maneuvers. Four different runaway trim settings were used to increase the difficulty of the turns (elevator-up, elevator-down, aileron-left, and aileron-right). Variables recorded included aircraft attitude, pilot applied forces, and electromyographic (EMG) activity. Discriminant function analysis was used to distinguish between novice and experienced pilots. Over all maneuvers, 70% of pilots were correctly classified as novice or experienced. Better levels of classification were achieved when maneuvers were analyzed individually (67-91%), although the maneuvers that required the greatest force application, elevator-up turns, were unable to discriminate between novice and experienced pilots. There were no differences in the phasing of muscle activity between experienced and novice pilots. The only consistent difference in EMG activity between novice and experienced pilots was the reduced EMG activity in the wrist extensors of experienced pilots (p < 0.05). The increased wrist extensor activity of the novice pilots is indicative of a distal control strategy, whereby distal muscles with smaller motor units are used to perform a task that requires precise control. Muscle activity sensors could be used to detect the onset of high G maneuvers prior to any change in aircraft attitude and control G-suit inflation accordingly.
NASA Technical Reports Server (NTRS)
Bennett, William H.; Kwatny, Harry G.; Lavigna, Chris; Blankenship, Gilmer
1994-01-01
The following topics are discussed: (1) modeling of articulated spacecraft as multi-flex-body systems; (2) nonlinear attitude control by adaptive partial feedback linearizing (PFL) control; (3) attitude dynamics and control for SSF/MRMS; and (4) performance analysis results for attitude control of SSF/MRMS.
Registered nurse intent to promote physical activity for hospitalised liver transplant recipients.
Pearson, Jocelyn A; Mangold, Kara; Kosiorek, Heidi E; Montez, Morgan; Smith, Diane M; Tyler, Brenda J
2017-12-26
To describe how registered nurse work motivation, attitudes, subjective norm and perceived behavioural control influence intention to promote physical activity in hospitalised adult liver transplant recipients. Descriptive study of clinical registered nurses caring for recipients of liver transplant at a tertiary medical centre. Intent to Mobilise Liver Transplant Recipient Scale, Work Extrinsic and Intrinsic Motivation Scale, and demographics were used to explore registered nurses' work motivation, attitudes, subjective norms, perceived behavioural control and intention to promote physical activity of hospitalised adult liver transplant recipients during the acute postoperative phase. Data analysis included demographics, comparison between scale items and analysis of factors predicting intent to mobilise. Factors predictive of intention to promote physical activity after liver transplant included appropriate knowledge to mobilise patients (R 2 = .40) and identification of physical activity as nursing staff priority (R 2 = .15) and responsibility (R 2 = .03). When implementing an early mobilisation protocol after the liver transplant, education on effects of physical activity in the immediate postoperative period are essential to promote implementation in practice. Nursing care environment and leadership must be supportive to ensure mobility is a registered nurse priority and responsibility. Nursing managers can leverage results to implement a mobility protocol. © 2017 John Wiley & Sons Ltd.
Hurtz, Gregory M; Williams, Kevin J
2009-05-01
This study investigated factors influencing ongoing participation in employee development activities. A multiple-indicator structural equation model building on the theory of planned behavior and prior employee development literature was tested with a survey across 4 organizations on 2 occasions. The model uses reactions to past participation and past supportiveness of the social and organizational environment as indirect antecedents of participation, filtered through their impact on attitudes and behavioral intentions toward future participation. Learning goal orientation also influenced attitudes toward participation. Whereas personal control over participation and higher levels of voluntariness were negatively related to participation, intentions to participate and availability of opportunities arose as strong predictors of higher participation rates. Many significant hypothesized paths were found, and 85% of the variance in participation was explained by the model variables. Increasing employee awareness of opportunities and managing positive attitudes toward those opportunities are recommended as key factors for increasing participation rates. (c) 2009 APA, all rights reserved.
Wang, Feilong; Xiao, Lily Dongxia; Wang, Kaifa; Li, Min; Yang, Yanni
2017-12-01
Community nurses play a crucial role in early detection and timely diagnosis of dementia. However, they are usually not prepared for the role through their formal education, particularly in low- and middle-income countries due to undeveloped nursing curriculum in dementia care. This paper describes a two-arm cluster-randomized controlled trial to improve community nurses' knowledge, attitudes, and practice changes using an innovative and interactive mobile phone applet-based activity in primary care settings. The intervention sites received dementia-specific training and control sites received care training for older people with disability. Both groups completed measures assessing dementia knowledge, attitudes, and intentions to make changes to achieve early detection and a timely diagnosis of dementia immediately after training and at 3-month follow-up. The intervention group provided feedback immediately after training and at 3-month follow-up. The main results show that the intervention group demonstrated significant improvement in dementia knowledge and attitudes from baseline immediately after training and at the 3-month follow-up. The intervention group also showed more intentions to make changes to achieve early detection of dementia. Feedback suggested the program was well-received. Overall, the program showed acceptability and feasibility in improving nurses' dementia knowledge, attitudes, and intentions to achieve early detection of dementia. Copyright © 2017 Elsevier Inc. All rights reserved.
Single Axis Attitude Control and DC Bus Regulation with Two Flywheels
NASA Technical Reports Server (NTRS)
Kascak, Peter E.; Jansen, Ralph H.; Kenny, Barbara; Dever, Timothy P.
2002-01-01
A computer simulation of a flywheel energy storage single axis attitude control system is described. The simulation models hardware which will be experimentally tested in the future. This hardware consists of two counter rotating flywheels mounted to an air table. The air table allows one axis of rotational motion. An inertia DC bus coordinator is set forth that allows the two control problems, bus regulation and attitude control, to be separated. Simulation results are presented with a previously derived flywheel bus regulator and a simple PID attitude controller.
Kwekkeboom, Kristine L; Vahl, Cheryl; Eland, Joann
2006-02-01
Deficiencies in end-of-life education may explain nursing students' reports of feeling anxious and unqualified to care for dying patients. A volunteer Palliative Care Companion program was developed to provide undergraduate nursing students with an experiential learning opportunity by spending time with dying patients and their families. To evaluate the impact of the Palliative Care Companion program on nursing students' knowledge, attitudes, and concerns about providing palliative care, and to describe companion students' volunteer activities. Quasiexperimental controlled pretest-posttest design. Fifty-two undergraduate nursing students (32 companion students, 20 controls) at a midwestern U.S. university with an affiliated hospital-based palliative care service. All participants completed the Palliative Care Quiz for Nurses, Attitudes Toward Palliative Care, and Concern About Caring for Dying Patients questionnaires at the beginning and end of the semester. Companion subjects also kept a journal describing their palliative care experiences. Attitude scores were not analyzed because of poor internal consistency of the questionnaire. Changes in scores on knowledge items did not reach significance. Concern scores decreased significantly from pretest to posttest in the companion group. After adjusting for pretest concern score, there was a trend toward lower concern score in the companion group compared to controls (p=0.07). Companion students' journals described activities including visiting patients, viewing end-of-life videos, attending educational and public lectures, independent reading, and making bereavement phone calls to family members. The Palliative Care Companion program did not produce significant improvements in knowledge and concerns compared to controls, but companion students described their participation as a meaningful learning experience.
Attitude ground support system for the solar maximum mission spacecraft
NASA Technical Reports Server (NTRS)
Nair, G.
1980-01-01
The SMM attitude ground support system (AGSS) supports the acquisition of spacecraft roll attitude reference, performs the in-flight calibration of the attitude sensor complement, supports onboard control autonomy via onboard computer data base updates, and monitors onboard computer (OBC) performance. Initial roll attitude acquisition is accomplished by obtaining a coarse 3 axis attitude estimate from magnetometer and Sun sensor data and subsequently refining it by processing data from the fixed head star trackers. In-flight calibration of the attitude sensor complement is achieved by processing data from a series of slew maneuvers designed to maximize the observability and accuracy of the appropriate alignments and biases. To ensure autonomy of spacecraft operation, the AGSS selects guide stars and computes sensor occultation information for uplink to the OBC. The onboard attitude control performance is monitored on the ground through periodic attitude determination and processing of OBC data in downlink telemetry. In general, the control performance has met mission requirements. However, software and hardware problems have resulted in sporadic attitude reference losses.
He, ZeFang
2014-01-01
An attitude control strategy based on Ziegler-Nichols rules for tuning PD (proportional-derivative) parameters of quadrotor helicopters is presented to solve the problem that quadrotor tends to be instable. This problem is caused by the narrow definition domain of attitude angles of quadrotor helicopters. The proposed controller is nonlinear and consists of a linear part and a nonlinear part. The linear part is a PD controller with PD parameters tuned by Ziegler-Nichols rules and acts on the quadrotor decoupled linear system after feedback linearization; the nonlinear part is a feedback linearization item which converts a nonlinear system into a linear system. It can be seen from the simulation results that the attitude controller proposed in this paper is highly robust, and its control effect is better than the other two nonlinear controllers. The nonlinear parts of the other two nonlinear controllers are the same as the attitude controller proposed in this paper. The linear part involves a PID (proportional-integral-derivative) controller with the PID controller parameters tuned by Ziegler-Nichols rules and a PD controller with the PD controller parameters tuned by GA (genetic algorithms). Moreover, this attitude controller is simple and easy to implement. PMID:25614879
X-33 Attitude Control System Design for Ascent, Transition, and Entry Flight Regimes
NASA Technical Reports Server (NTRS)
Hall, Charles E.; Gallaher, Michael W.; Hendrix, Neal D.
1998-01-01
The Vehicle Control Systems Team at Marshall Space Flight Center, Systems Dynamics Laboratory, Guidance and Control Systems Division is designing under a cooperative agreement with Lockheed Martin Skunkworks, the Ascent, Transition, and Entry flight attitude control system for the X-33 experimental vehicle. Ascent flight control begins at liftoff and ends at linear aerospike main engine cutoff (NECO) while Transition and Entry flight control begins at MECO and concludes at the terminal area energy management (TAEM) interface. TAEM occurs at approximately Mach 3.0. This task includes not only the design of the vehicle attitude control systems but also the development of requirements for attitude control system components and subsystems. The X-33 attitude control system design is challenged by a short design cycle, the design environment (Mach 0 to about Mach 15), and the X-33 incremental test philosophy. The X-33 design-to-launch cycle of less than 3 years requires a concurrent design approach while the test philosophy requires design adaptation to vehicle variations that are a function of Mach number and mission profile. The flight attitude control system must deal with the mixing of aerosurfaces, reaction control thrusters, and linear aerospike engine control effectors and handle parasitic effects such as vehicle flexibility and propellant sloshing from the uniquely shaped propellant tanks. The attitude control system design is, as usual, closely linked to many other subsystems and must deal with constraints and requirements from these subsystems.
Sychareun, Vanphanom; Phengsavanh, Alongkone; Hansana, Visanou; Chaleunvong, Kongmany; Kounnavong, Sengchan; Sawhney, Monika; Durham, Jo
2013-01-01
Research indicates that adolescents in low-income countries have an early sexual debut and engage in risky sexual behaviours. Few studies in low-income countries however, have explored the factors that influence young people's sexual behaviours. This study examined individual, family and peer-level factors associated with premarital sexual behaviours in the Lao People's Democratic Republic (PDR). A cross-sectional survey was undertaken with unmarried youth aged 18 to 24 years (N = 1200) in Vientiane Capital City. Logistic regression models, controlling for confounding variables, were employed to test for the contribution of factors influencing premarital sexual activity. Most respondents held positive attitudes towards premarital sex, with males having more liberal attitudes than females (mean score of 2.68 vs. 2.32, p < 0.001). Prevalence of premarital sexual activity was higher among males than females (44.7% and 19.2%, respectively). Predictors of premarital sex for males were age, sexual attitudes, perceived parental expectations regarding sex, dating and peer influence. For females, predictors were father's level of education, parent-youth sexual communication, peer influence and liberal sexual attitudes. The results highlight the role of parent-youth interaction and peer influence. The results suggest the need for a range of strategies at the individual, peer and family level, as well as a gender-specific focus.
ATS-6 engineering performance report. Volume 2: Orbit and attitude controls
NASA Technical Reports Server (NTRS)
Wales, R. O. (Editor)
1981-01-01
Attitude control is reviewed, encompassing the attitude control subsystem, spacecraft attitude precision pointing and slewing adaptive control experiment, and RF interferometer experiment. The spacecraft propulsion system (SPS) is discussed, including subsystem, SPS design description and validation, orbital operations and performance, in-orbit anomalies and contingency operations, and the cesium bombardment ion engine experiment. Thruster failure due to plugging of the propellant feed passages, a major cause for mission termination, are considered among the critical generic failures on the satellite.
Attitude Control Propulsion Components, Volume 1
NASA Technical Reports Server (NTRS)
1974-01-01
Effort was made to include as much engineering information on each component as possible, consistent with usefulness and catalog size limitations. The contents of this catalog contain components which were qualified for use with spacecraft monopropellant hydrazine and inert gas attitude control systems. Thrust ranges up to 44.5 N (10.0 lbf) for hydrazine and inert gas sytems were considered. Additionally, some components qualified for uses other than spacecraft attitude control are included because they are suitable for use in attitude controls systems.
NASA Astrophysics Data System (ADS)
Chak, Yew-Chung; Varatharajoo, Renuganth
2016-07-01
Many spacecraft attitude control systems today use reaction wheels to deliver precise torques to achieve three-axis attitude stabilization. However, irrecoverable mechanical failure of reaction wheels could potentially lead to mission interruption or total loss. The electrically-powered Solar Array Drive Assemblies (SADA) are usually installed in the pitch axis which rotate the solar arrays to track the Sun, can produce torques to compensate for the pitch-axis wheel failure. In addition, the attitude control of a flexible spacecraft poses a difficult problem. These difficulties include the strong nonlinear coupled dynamics between the rigid hub and flexible solar arrays, and the imprecisely known system parameters, such as inertia matrix, damping ratios, and flexible mode frequencies. In order to overcome these drawbacks, the adaptive Jacobian tracking fuzzy control is proposed for the combined attitude and sun-tracking control problem of a flexible spacecraft during attitude maneuvers in this work. For the adaptation of kinematic and dynamic uncertainties, the proposed scheme uses an adaptive sliding vector based on estimated attitude velocity via approximate Jacobian matrix. The unknown nonlinearities are approximated by deriving the fuzzy models with a set of linguistic If-Then rules using the idea of sector nonlinearity and local approximation in fuzzy partition spaces. The uncertain parameters of the estimated nonlinearities and the Jacobian matrix are being adjusted online by an adaptive law to realize feedback control. The attitude of the spacecraft can be directly controlled with the Jacobian feedback control when the attitude pointing trajectory is designed with respect to the spacecraft coordinate frame itself. A significant feature of this work is that the proposed adaptive Jacobian tracking scheme will result in not only the convergence of angular position and angular velocity tracking errors, but also the convergence of estimated angular velocity to the actual angular velocity. Numerical results are presented to demonstrate the effectiveness of the proposed scheme in tracking the desired attitude, as well as suppressing the elastic deflection effects of solar arrays during maneuver.
A solenoid failure detection system for cold gas attitude control jet valves
NASA Technical Reports Server (NTRS)
Johnston, P. A.
1970-01-01
The development of a solenoid valve failure detection system is described. The technique requires the addition of a radioactive gas to the propellant of a cold gas jet attitude control system. Solenoid failure is detected with an avalanche radiation detector located in the jet nozzle which senses the radiation emitted by the leaking radioactive gas. Measurements of carbon monoxide leakage rates through a Mariner type solenoid valve are presented as a function of gas activity and detector configuration. A cylindrical avalanche detector with a factor of 40 improvement in leak sensitivity is proposed for flight systems because it allows the quantity of radioactive gas that must be added to the propellant to be reduced to a practical level.
The psychosexual histories of young women with bulimia.
Abraham, S F; Bendit, N; Mason, C; Mitchell, H; O'Connor, N; Ward, J; Young, S; Llewellyn-Jones, D
1985-03-01
While it is known that anorexia nervosa patients show a wide range of sexual knowledge, attitudes and practices, the psychosexual histories of bulimia patients have not been studied. In this paper the psychosexual histories of 20 bulimic patients and 20 matched control subjects are presented. Bulimic patients were more likely to experience orgasm with masturbation, were more likely to have experimented with anal intercourse, and were more likely to describe their libido as 'above average.' Control subjects were more likely to experience orgasm during sexual intercourse. Bulimic patients associated high body weights with unattractiveness, and tended to withdraw from social and sexual activity at high weights. In other aspects of their sexual behaviour, and in their attitudes to sexual matters, the two groups were similar.
A new momentum management controller for the space station
NASA Technical Reports Server (NTRS)
Wie, B.; Byun, K. W.; Warren, V. W.
1988-01-01
A new approach to CMG (control moment gyro) momentum management and attitude control of the Space Station is developed. The control algorithm utilizes both the gravity-gradient and gyroscopic torques to seek torque equilibrium attitude in the presence of secular and cyclic disturbances. Depending upon mission requirements, either pitch attitude or pitch-axis CMG momentum can be held constant: yaw attitude and roll-axis CMG momentum can be held constant, while roll attitude and yaw-axis CMG momentum cannot be held constant. As a result, the overall attitude and CMG momentum oscillations caused by cyclic aero-dynamic disturbances are minimized. A state feedback controller with minimal computer storage requirement for gain scheduling is also developed. The overall closed-loop system is stable for + or - 30 percent inertia matrix variations and has more than + or - 10 dB and 45 deg stability margins in each loop.
Research on Design of MUH Attitude Stability Augmentation Control System
NASA Astrophysics Data System (ADS)
Fan, Shigang
2017-09-01
Attitude stability augmentation control system with a lower cost need to be designed so that MUH (Mini Unmanned Helicopter) can adapt to different types of geographic environment and fly steadily although the weather may be bad. Attitude feedback was calculated mainly by filtering estimation within attitude acquisition module in this system. Stability augmentation can be improved mainly by PI. This paper will depict running principle and designing process of MUH attitude stability augmentation control system and algorithm that is considered as an important part in this system.
Attitudes as Object-Evaluation Associations of Varying Strength
Fazio, Russell H.
2009-01-01
Historical developments regarding the attitude concept are reviewed, and set the stage for consideration of a theoretical perspective that views attitude, not as a hypothetical construct, but as evaluative knowledge. A model of attitudes as object-evaluation associations of varying strength is summarized, along with research supporting the model’s contention that at least some attitudes are represented in memory and activated automatically upon the individual’s encountering the attitude object. The implications of the theoretical perspective for a number of recent discussions related to the attitude concept are elaborated. Among these issues are the notion of attitudes as “constructions,” the presumed malleability of automatically-activated attitudes, correspondence between implicit and explicit measures of attitude, and postulated dual or multiple attitudes. PMID:19424447
Steady-state simulation program for attitude control propulsion systems
NASA Technical Reports Server (NTRS)
Heinmiller, P. J.
1973-01-01
The formulation and the engineering equations employed in the steady state attitude control propulsion system simulation program are presented. The objective of this program is to aid in the preliminary design and development of propulsion systems used for spacecraft attitude control. The program simulates the integrated operation of the many interdependent components typically comprising an attitude control propulsion system. Flexibility, generality, ease of operation, and speed consistent with adequate accuracy were overriding considerations during the development of this program. Simulation modules were developed representing the various types of fluid components typically encountered in an attitude control propulsion system. These modules are basically self-contained and may be arranged by the program user into desired configuration through the program input data.
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-98 Mission Specialists Robert Curbeam (center left) and Tom Jones (center right) practice with tools that will be used on extravehicular activities on their mission. The STS-98 crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In the Orbiter Processing Facility, STS-98 Mission Specialists Robert Curbeam (center left) and Tom Jones (center right) practice with tools that will be used on extravehicular activities on their mission. The STS-98 crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
Precise attitude determination of defunct satellite laser ranging tragets
NASA Astrophysics Data System (ADS)
Pittet, Jean-Noel; Schildknecht, Thomas; Silha, Jiri
2016-07-01
The Satellite Laser Ranging (SLR) technology is used to determine the dynamics of objects equipped with so-called retro-reflectors or retro-reflector arrays (RRA). This type of measurement allows to range to the spacecraft with very high precision, which leads to determination of very accurate orbits. Non-active spacecraft, which are not any more attitude controlled, tend to start to spin or tumble under influence of the external and internal torques. Such a spinning can be around one constant axis of rotation or it can be more complex, when also precession and nutation motions are present. The rotation of the RRA around the spacecraft's centre of mass can create both a oscillation pattern of laser range signal and a periodic signal interruption when the RRA is hidden behind the satellite. In our work we will demonstrate how the SLR ranging technique to cooperative targets can be used to determine precisely their attitude state. The processing of the obtained data will be discussed, as well as the attitude determination based on parameters estimation. Continuous SLR measurements to one target can allow to accurately monitor attitude change over time which can be further used for the future attitude modelling. We will show our solutions of the attitude states determined for the non-active ESA satellite ENVISAT based on measurements acquired during year 2013-2015 by Zimmerwald SLR station, Switzerland. The angular momentum shows a stable behaviour with respect to the orbital plane but is not aligned with orbital momentum. The determination of the inertial rotation over time, shows it evolving between 130 to 190 seconds within two year. Parameter estimation also bring a strong indication of a retrograde rotation. Results on other former satellites in low and medium Earth orbit such as TOPEX/Poseidon or GLONASS type will be also presented.
Laberge, Suzanne; Bush, Paula Louise; Chagnon, Miguel
2012-01-01
To implement a culturally tailored physical activity (PA) promotion program (FunAction) and to assess its impact on five self-regulation skills and attitudes in adolescents. Design . The design and implementation of the FunAction program were informed by social marketing principles. The study used a quasi-experimental approach to assess the impact of the program on specific outcome variables. A multiethnic, underserved middle school in Montreal, Quebec, Canada. The intervention group was made up of grade 8 students (n = 165) and the control group was made up of grade 7 students (n = 137). During the 16-week intervention, adolescents were able to choose from a variety of 45-minute cardiovascular PAs offered daily during their school lunch period. Adolescents participated in the activities on a voluntary basis. A self-report questionnaire was administered preintervention and postintervention to measure adolescents' scores on the following self-regulation skills and attitudes: self-control, self-esteem, attention/concentration, social competence, and interethnic relationships. Three-way repeated measures analyses of variance and correlational analyses were used. Results . A significant improvement was observed only in attention/concentration. Girls' attention/concentration scores improved significantly in the intervention group compared to the control group (F(1,127) = 16.26, p < .001). The improvement in attention/concentration scores for boys in the intervention group was correlated with their frequency of participation in the program PAs (r = .24, p = .008). Using social marketing principles can help encourage adolescents from underserved, multiethnic milieus to participate in PA during their school lunch hour. Furthermore, voluntary participation in a culturally tailored PA program can improve youths' attention/concentration.
Bouso, José Carlos; González, Débora; Fondevila, Sabela; Cutchet, Marta; Fernández, Xavier; Ribeiro Barbosa, Paulo César; Alcázar-Córcoles, Miguel Ángel; Araújo, Wladimyr Sena; Barbanoj, Manel J; Fábregas, Josep Maria; Riba, Jordi
2012-01-01
Ayahuasca is an Amazonian psychoactive plant beverage containing the serotonergic 5-HT(2A) agonist N,N-dimethyltryptamine (DMT) and monoamine oxidase-inhibiting alkaloids (harmine, harmaline and tetrahydroharmine) that render it orally active. Ayahuasca ingestion is a central feature in several Brazilian syncretic churches that have expanded their activities to urban Brazil, Europe and North America. Members of these groups typically ingest ayahuasca at least twice per month. Prior research has shown that acute ayahuasca increases blood flow in prefrontal and temporal brain regions and that it elicits intense modifications in thought processes, perception and emotion. However, regular ayahuasca use does not seem to induce the pattern of addiction-related problems that characterize drugs of abuse. To study the impact of repeated ayahuasca use on general psychological well-being, mental health and cognition, here we assessed personality, psychopathology, life attitudes and neuropsychological performance in regular ayahuasca users (n = 127) and controls (n = 115) at baseline and 1 year later. Controls were actively participating in non-ayahuasca religions. Users showed higher Reward Dependence and Self-Transcendence and lower Harm Avoidance and Self-Directedness. They scored significantly lower on all psychopathology measures, showed better performance on the Stroop test, the Wisconsin Card Sorting Test and the Letter-Number Sequencing task from the WAIS-III, and better scores on the Frontal Systems Behavior Scale. Analysis of life attitudes showed higher scores on the Spiritual Orientation Inventory, the Purpose in Life Test and the Psychosocial Well-Being test. Despite the lower number of participants available at follow-up, overall differences with controls were maintained one year later. In conclusion, we found no evidence of psychological maladjustment, mental health deterioration or cognitive impairment in the ayahuasca-using group.
Bouso, José Carlos; González, Débora; Fondevila, Sabela; Cutchet, Marta; Ribeiro Barbosa, Paulo César; Alcázar-Córcoles, Miguel Ángel; Araújo, Wladimyr Sena; Fábregas, Josep Maria; Riba, Jordi
2012-01-01
Ayahuasca is an Amazonian psychoactive plant beverage containing the serotonergic 5-HT2A agonist N,N-dimethyltryptamine (DMT) and monoamine oxidase-inhibiting alkaloids (harmine, harmaline and tetrahydroharmine) that render it orally active. Ayahuasca ingestion is a central feature in several Brazilian syncretic churches that have expanded their activities to urban Brazil, Europe and North America. Members of these groups typically ingest ayahuasca at least twice per month. Prior research has shown that acute ayahuasca increases blood flow in prefrontal and temporal brain regions and that it elicits intense modifications in thought processes, perception and emotion. However, regular ayahuasca use does not seem to induce the pattern of addiction-related problems that characterize drugs of abuse. To study the impact of repeated ayahuasca use on general psychological well-being, mental health and cognition, here we assessed personality, psychopathology, life attitudes and neuropsychological performance in regular ayahuasca users (n = 127) and controls (n = 115) at baseline and 1 year later. Controls were actively participating in non-ayahuasca religions. Users showed higher Reward Dependence and Self-Transcendence and lower Harm Avoidance and Self-Directedness. They scored significantly lower on all psychopathology measures, showed better performance on the Stroop test, the Wisconsin Card Sorting Test and the Letter-Number Sequencing task from the WAIS-III, and better scores on the Frontal Systems Behavior Scale. Analysis of life attitudes showed higher scores on the Spiritual Orientation Inventory, the Purpose in Life Test and the Psychosocial Well-Being test. Despite the lower number of participants available at follow-up, overall differences with controls were maintained one year later. In conclusion, we found no evidence of psychological maladjustment, mental health deterioration or cognitive impairment in the ayahuasca-using group. PMID:22905130
NASA Astrophysics Data System (ADS)
White, M. A.; Tcherednichenko, I.; Hamar, M.; Taylor, M. J.; Litizzette, L.
2006-12-01
United States funding agencies increasingly are supporting activities designed to increase the enrollment of United States high school students in science, math, or engineering careers. However, in many cases, the likely outcomes of educational activities are unknown. A common approach within the physical and natural sciences is to provide high school aged students with a summer research experience, with the expectation that such experiences will increase student interest in science, possibly as a career choice. With funding support from the National Aeronautics and Space Administration New Investigator Grant program, we conducted a controlled experiment to test this assumption. In collaboration with Mountain Crest High School in Logan, UT, we recruited 40 students currently enrolled in science courses, assessed attitudes towards science (with informed consent), and randomly assigned 20 students to a control group and 20 students to an experimental group. Students in the experimental group were paired with faculty and graduate students in a wide range of field and laboratory research groups in natural resources and biology. Students were employed in at least two different research groups for an average of 30-40 hours per week for eight weeks in the summer of 2006. Following the completion of the summer work experience, we again assessed attitudes towards science in both groups and gathered additional information from the experimental group on satisfaction with the work experience and reasons for participating. Results are presented and discussed.
Predicting Return of Fear Following Exposure Therapy With an Implicit Measure of Attitudes
Vasey, Michael W.; Harbaugh, Casaundra N.; Buffington, Adam G.; Jones, Christopher R.; Fazio, Russell H.
2012-01-01
We sought to advance understanding of the processes underlying the efficacy of exposure therapy and particularly the phenomenon of return of fear (ROF) following treatment by drawing on a social psychological view of phobias as attitudes. Specifically, a dual process theory of attitude-related behavior predicts that a positive response to exposure therapy may reflect change in either the automatic (the attitude representation itself) or controlled (skills and confidence at coping with the fear) responses to the phobic stimulus, or both. However, if the attitude representation remains negative following treatment, ROF should be more likely. We tested this hypothesis in a clinical sample of individuals with public speaking phobia using a single-session exposure therapy protocol previously shown to be efficacious but also associated with some ROF. Consistent with predictions, a post-treatment implicit measure of attitudes toward public speaking (the Personalized Implicit Association Test [PIAT]) predicted ROF at 1-month follow-up. These results suggest that change in the automatically activated attitude toward the phobic stimulus is an important goal of exposure therapy and that an implicit measure like the PIAT can provide a useful measure of such change by which to gauge the adequacy of exposure treatment and predict its long-term efficacy. PMID:23085186
Guo-Hua, Peng; Zhu-Hua, Hu; Wei, Hua; Ke, Qian; Xiao-Gang, Li; Zhi-Shu, Zhang; Zhi-Gang, Chen; Xiao-Wu, Feng
2017-06-26
To understand the present situation of the chronic schistosomiasis patients' knowledge, attitude and practice on schistosomiasis control in Nanchang City. The knowledge, attitude and values on schistosomiasis control of 523 chronic schistosomiasis patients in Nanchang County, Jinxian County and Xinjian District in the Poyang Lake District were investigated with questionnaires. And the accuracy rates of the knowledge, attitude and practice among the patient groups of different counties, genders, age groups, occupations and educational levels were analyzed. The accuracy rates of the knowledge, attitude and practice of patients on schistosomiasis control were 95.76%, 82.80%, and 81.73% in Nanchang County; 91.37%, 93.32%, and 76.48% in Jinxian County; 88.25%, 67.56%, and 49.40% in Xinjian District. In the accuracy rates of knowledge, attitude and practice, the differences among the three counties (districts) were statistically significant ( χ 2 = 57.511-301.378, all P < 0.05) . The accuracy rates of chronic schistosomiasis patients' attitude and practice on schistosomiasis control in Nanchang City remain low. Therefore, the intensity of attitude and practice intervention should be strengthened in the Poyang Lake District in order to enhance the self-protection awareness of the patients.
2011-01-01
Background Governments in several countries attempt to strengthen user participation through instructing health care organisations to plan and implement activities such as user representation in administrational boards, improved information to users, and more individual user participation in clinical work. The professionals are central in implementing initiatives to enhance user participation in organisations, but no controlled studies have been conducted on the effect on professionals from implementing institutional development plans. The objective was to investigate whether implementing a development plan intending to enhance user participation in a mental health hospital had any effect on the professionals' knowledge, practice, or attitudes towards user participation. Methods This was a non-randomized controlled study including professionals from three mental health hospitals in Central Norway. A development plan intended to enhance user participation was implemented in one of the hospitals as a part of a larger re-organizational process. The plan included i.e. establishing a patient education centre and a user office, purchasing of user expertise, appointing contact professionals for next of kin, and improving of the centre's information and the professional culture. The professionals at the intervention hospital thus constituted the intervention group, while the professionals at two other hospitals participated as control group. All professionals were invited to answer the Consumer Participation Questionnaire (CPQ) and additional questions, focusing on knowledge, practice, and attitudes towards user participation, two times with a 16 months interval. Results A total of 438 professionals participated (55% response rate). Comparing the changes in the intervention group with the changes in the control group revealed no statistically significant differences at a 0.05 level. The implementation of the development plan thus had no measurable effect on the professionals' knowledge, practice, or attitudes at the intervention hospital, compared to the control hospitals. Conclusion This is the first controlled study on the effect on professionals from implementing a development plan to enhance user participation in a mental health hospital. The plan had no effect on professionals' knowledge, practice, or attitudes. This can be due to the quality of the development plan, the implementation process, and/or the suitability of the outcome measures. PMID:22047466
Rise, Marit By; Grimstad, Hilde; Solbjør, Marit; Steinsbekk, Aslak
2011-11-02
Governments in several countries attempt to strengthen user participation through instructing health care organisations to plan and implement activities such as user representation in administrational boards, improved information to users, and more individual user participation in clinical work. The professionals are central in implementing initiatives to enhance user participation in organisations, but no controlled studies have been conducted on the effect on professionals from implementing institutional development plans. The objective was to investigate whether implementing a development plan intending to enhance user participation in a mental health hospital had any effect on the professionals' knowledge, practice, or attitudes towards user participation. This was a non-randomized controlled study including professionals from three mental health hospitals in Central Norway. A development plan intended to enhance user participation was implemented in one of the hospitals as a part of a larger re-organizational process. The plan included i.e. establishing a patient education centre and a user office, purchasing of user expertise, appointing contact professionals for next of kin, and improving of the centre's information and the professional culture. The professionals at the intervention hospital thus constituted the intervention group, while the professionals at two other hospitals participated as control group. All professionals were invited to answer the Consumer Participation Questionnaire (CPQ) and additional questions, focusing on knowledge, practice, and attitudes towards user participation, two times with a 16 months interval. A total of 438 professionals participated (55% response rate). Comparing the changes in the intervention group with the changes in the control group revealed no statistically significant differences at a 0.05 level. The implementation of the development plan thus had no measurable effect on the professionals' knowledge, practice, or attitudes at the intervention hospital, compared to the control hospitals. This is the first controlled study on the effect on professionals from implementing a development plan to enhance user participation in a mental health hospital. The plan had no effect on professionals' knowledge, practice, or attitudes. This can be due to the quality of the development plan, the implementation process, and/or the suitability of the outcome measures.
Recent Developments in Smart Adaptive Structures for Solar Sailcraft
NASA Technical Reports Server (NTRS)
Whorton, M. S.; Kim, Y. K.; Oakley, J.; Adetona, O.; Keel, L. H.
2007-01-01
The "Smart Adaptive Structures for Solar Sailcraft" development activity at MSFC has investigated issues associated with understanding how to model and scale the subsystem and multi-body system dynamics of a gossamer solar sailcraft with the objective of designing sailcraft attitude control systems. This research and development activity addressed three key tasks that leveraged existing facilities and core competencies of MSFC to investigate dynamics and control issues of solar sails. Key aspects of this effort included modeling and testing of a 30 m deployable boom; modeling of the multi-body system dynamics of a gossamer sailcraft; investigation of control-structures interaction for gossamer sailcraft; and development and experimental demonstration of adaptive control technologies to mitigate control-structures interaction.
NASA Technical Reports Server (NTRS)
Moore, W.; Prensky, W. (Editor)
1974-01-01
The activities of the ATS-6 spacecraft are reviewed. The following subsystems and experiments are summarized: (1) radio beacon experiments; (2) spacecraft attitude precision pointing and slewing adaptive control experiment; (3) satellite instruction television experiment; (4) thermal control subsystem; (5) spacecraft propulsion subsystem; (6) telemetry and control subsystem; (7) millimeter wave experiment; and (8) communications subsystem. The results of performance evaluation of its subsystems and experiments are presented.
Attitude stabilization of a rigid spacecraft using two momentum wheel actuators
NASA Technical Reports Server (NTRS)
Krishnan, Hariharan; Mcclamroch, N. Harris; Reyhanoglu, Mahmut
1993-01-01
It is well known that three momentum wheel actuators can be used to control the attitude of a rigid spacecraft and that arbitrary reorientation maneuvers of the spacecraft can be accomplished using smooth feedback. If failure of one of the momentum wheel actuators occurs, it is demonstrated that two momentum wheel actuators can be used to control the attitude of a rigid spacecraft and that arbitrary reorientation maneuvers of the spacecraft can be accomplished. Although the complete spacecraft equations are not controllable, the spacecraft equations are small time locally controllable in a reduced nonlinear sense. The reduced spacecraft dynamics cannot be asymptotically stabilized to any equilibrium attitude using a time-variant continuous feedback control law, but discontinuous feedback control strategies are constructed which stabilize any equilibrium attitude of the spacecraft in finite time. Consequently, reorientation of the spacecraft can be accomplished using discontinuous feedback control.
Categorization and Prediction of Crimes of Passion Based on Attitudes Toward Violence.
Guan, Muzhen; Li, Xiaojing; Xiao, Wei; Miao, Danmin; Liu, Xufeng
2017-11-01
The present study explored implicit and explicit attitudes toward violence in crimes of passion. Criminals ( n = 96) who had perpetrated crimes of passion and students ( n = 100) participated in this study. Explicit attitudes toward violence were evaluated using the Abnormal Personality Risk Inventory (APRI), and implicit attitude toward violence was evaluated using the Implicit Association Test (IAT). Results indicated that APRI scores of the perpetrators were significantly higher than that of the control group ( p < .05), suggesting that explicit attitudes toward violence could discriminate between the criminals and the control group. There was a significant IAT effect demonstrating a negative implicit attitude toward violence in both the control group and in the criminals ( n = 68); whereas there was a significant IAT effect manifesting a positive implicit attitude toward violence in the criminals ( n = 16) only. These results suggest that combining explicit and implicit attitudes could provide an empirical classification of crimes of passion.
An-Min Zou; Kumar, K D; Zeng-Guang Hou; Xi Liu
2011-08-01
A finite-time attitude tracking control scheme is proposed for spacecraft using terminal sliding mode and Chebyshev neural network (NN) (CNN). The four-parameter representations (quaternion) are used to describe the spacecraft attitude for global representation without singularities. The attitude state (i.e., attitude and velocity) error dynamics is transformed to a double integrator dynamics with a constraint on the spacecraft attitude. With consideration of this constraint, a novel terminal sliding manifold is proposed for the spacecraft. In order to guarantee that the output of the NN used in the controller is bounded by the corresponding bound of the approximated unknown function, a switch function is applied to generate a switching between the adaptive NN control and the robust controller. Meanwhile, a CNN, whose basis functions are implemented using only desired signals, is introduced to approximate the desired nonlinear function and bounded external disturbances online, and the robust term based on the hyperbolic tangent function is applied to counteract NN approximation errors in the adaptive neural control scheme. Most importantly, the finite-time stability in both the reaching phase and the sliding phase can be guaranteed by a Lyapunov-based approach. Finally, numerical simulations on the attitude tracking control of spacecraft in the presence of an unknown mass moment of inertia matrix, bounded external disturbances, and control input constraints are presented to demonstrate the performance of the proposed controller.
Wang, Yan; Wang, Lei; Cui, Xianghua; Fang, Yuan; Chen, Qianqiu; Wang, Ya; Qiang, Yao
2015-12-01
Self-regulatory resources and trait self-control have been found to moderate the impulse-behavior relationship. The current study investigated whether the interaction of self-regulatory resources and trait self-control moderates the association between implicit attitudes and food consumption. One hundred twenty female participants were randomly assigned to either a depletion condition in which their self-regulatory resources were reduced or a no-depletion condition. Participants' implicit attitudes for chocolate were measured with the Single Category Implicit Association Test and self-report measures of trait self-control were collected. The dependent variable was chocolate consumption in an ostensible taste and rate task. Implicit attitudes predicted chocolate consumption in depleted participants but not in non-depleted participants. However, this predictive power of implicit attitudes on eating in depleted condition disappeared in participants with high trait self-control. Thus, trait self-control and self-regulatory resources interact to moderate the prediction of implicit attitude on eating behavior. Results suggest that high trait self-control buffers the effect of self-regulatory depletion on impulsive eating. Copyright © 2015 Elsevier Ltd. All rights reserved.
Experiments study on attitude coupling control method for flexible spacecraft
NASA Astrophysics Data System (ADS)
Wang, Jie; Li, Dongxu
2018-06-01
High pointing accuracy and stabilization are significant for spacecrafts to carry out Earth observing, laser communication and space exploration missions. However, when a spacecraft undergoes large angle maneuver, the excited elastic oscillation of flexible appendages, for instance, solar wing and onboard antenna, would downgrade the performance of the spacecraft platform. This paper proposes a coupling control method, which synthesizes the adaptive sliding mode controller and the positive position feedback (PPF) controller, to control the attitude and suppress the elastic vibration simultaneously. Because of its prominent performance for attitude tracking and stabilization, the proposed method is capable of slewing the flexible spacecraft with a large angle. Also, the method is robust to parametric uncertainties of the spacecraft model. Numerical simulations are carried out with a hub-plate system which undergoes a single-axis attitude maneuver. An attitude control testbed for the flexible spacecraft is established and experiments are conducted to validate the coupling control method. Both numerical and experimental results demonstrate that the method discussed above can effectively decrease the stabilization time and improve the attitude accuracy of the flexible spacecraft.
Tabak, Naomi T; Horan, William P; Green, Michael F
2015-10-01
Mindfulness-based interventions are gaining empirical support as alternative or adjunctive treatments for a variety of mental health conditions, including anxiety, depression, and substance use disorders. Emerging evidence now suggests that mindfulness-based treatments may also improve clinical features of schizophrenia, including negative symptoms. However, no research has examined the construct of mindfulness and its correlates in schizophrenia. In this study, we examined self-reported mindfulness in patients (n=35) and controls (n=25) using the Five-Facet Mindfulness Questionnaire. We examined correlations among mindfulness, negative symptoms, and psychological constructs associated with negative symptoms and adaptive functioning, including motivation, emotion regulation, and dysfunctional attitudes. As hypothesized, patients endorsed lower levels of mindfulness than controls. In patients, mindfulness was unrelated to negative symptoms, but it was associated with more adaptive emotion regulation (greater reappraisal) and beliefs (lower dysfunctional attitudes). Some facets of mindfulness were also associated with self-reported motivation (behavioral activation and inhibition). These patterns of correlations were similar in patients and controls. Findings from this initial study suggest that schizophrenia patients may benefit from mindfulness-based interventions because they (a) have lower self-reported mindfulness than controls and (b) demonstrate strong relationships between mindfulness and psychological constructs related to adaptive functioning. Copyright © 2015 Elsevier B.V. All rights reserved.
Lau, May; Lin, Hua; Flores, Glenn
2014-08-01
To identify factors associated with a positive pregnancy attitude among sexually active US teen females. Secondary database analysis of the National Survey of Family Growth. Adolescent females 15-19 years old. Nationally representative sample. Bivariate and multivariable analyses were performed of the 2002 and 2006-08 cycles to examine whether sociodemographic factors, contraceptive history, sexual education and behavior history, medical services history, and family and sexual attitudes were associated with a positive pregnancy attitude among sexually active teen females. Among the 975 sexually active US adolescent females surveyed, 15% reported a positive pregnancy attitude. Compared with adolescent females with a negative pregnancy attitude, those females with a positive pregnancy attitude were significantly (P < .05) more likely to have public insurance (43% vs 20%), to be poor (33% vs 10%), to have reached menarche at an earlier age (12 years old vs 13 years old), ever have HIV tested (35% vs 23%), but less likely to have ever been forced to have sex (1% vs 10%). In multivariable analyses, Latino race/ethnicity was associated with triple the odds, and African-American double the odds, of a positive pregnancy attitude. Older age of menarche and higher family income were associated with reduced odds of a positive pregnancy attitude. One in 7 sexually active US adolescent females had a positive pregnancy attitude. Minority race/ethnicity was associated with greater odds of a positive pregnancy attitude, whereas older age of menarche and a higher family income were associated with lower odds of a positive pregnancy attitude. Assessing pregnancy attitudes for these groups of adolescent females might prove useful to decrease adolescent pregnancy rates. Copyright © 2014 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.
The accuracy of dynamic attitude propagation
NASA Technical Reports Server (NTRS)
Harvie, E.; Chu, D.; Woodard, M.
1990-01-01
Propagating attitude by integrating Euler's equation for rigid body motion has long been suggested for the Earth Radiation Budget Satellite (ERBS) but until now has not been implemented. Because of limited Sun visibility, propagation is necessary for yaw determination. With the deterioration of the gyros, dynamic propagation has become more attractive. Angular rates are derived from integrating Euler's equation with a stepsize of 1 second, using torques computed from telemetered control system data. The environmental torque model was quite basic. It included gravity gradient and unshadowed aerodynamic torques. Knowledge of control torques is critical to the accuracy of dynamic modeling. Due to their coarseness and sparsity, control actuator telemetry were smoothed before integration. The dynamic model was incorporated into existing ERBS attitude determination software. Modeled rates were then used for attitude propagation in the standard ERBS fine-attitude algorithm. In spite of the simplicity of the approach, the dynamically propagated attitude matched the attitude propagated with good gyros well for roll and yaw but diverged up to 3 degrees for pitch because of the very low resolution in pitch momentum wheel telemetry. When control anomalies significantly perturb the nominal attitude, the effect of telemetry granularity is reduced and the dynamically propagated attitudes are accurate on all three axes.
Mood state dependency of dysfunctional attitudes in bipolar affective disorder.
Babakhani, Anet; Startup, Mike
2012-01-01
Studies of cognitive styles among euthymic people with bipolar affective disorder (BAD) without use of mood induction techniques to access those cognitive styles give misleading impressions of normality of those cognitions. The aim of this study was to assess dysfunctional attitudes of participants with BAD, and control participants with no previous psychiatric histories, after mood inductions. Sad and happy moods were induced within 49 BAD and 37 controls. Dysfunctional attitudes were measured following mood inductions using the Dysfunctional Attitude Scale-short form (DAS-24), which has three subscales of achievement, interpersonal, and goal attainment. It was hypothesised that within BAD the sad mood induction would help in accessing dysfunctional attitudes in all three domains relative to the happy mood induction. This was supported. It was also hypothesised that the mood inductions would not affect dysfunctional attitudes within controls. This was supported. When diagnosis was entered as a between group variable, achievement dysfunctional attitudes were significantly higher in BAD compared to controls after a happy induction. Both sad and happy moods provoked higher levels of dysfunctional attitudes within BAD. Euphoria may be related to elevated achievement dysfunctional attitudes, raising risk for mania.
Attitude Control System Design for the Solar Dynamics Observatory
NASA Technical Reports Server (NTRS)
Starin, Scott R.; Bourkland, Kristin L.; Kuo-Chia, Liu; Mason, Paul A. C.; Vess, Melissa F.; Andrews, Stephen F.; Morgenstern, Wendy M.
2005-01-01
The Solar Dynamics Observatory mission, part of the Living With a Star program, will place a geosynchronous satellite in orbit to observe the Sun and relay data to a dedicated ground station at all times. SDO remains Sun- pointing throughout most of its mission for the instruments to take measurements of the Sun. The SDO attitude control system is a single-fault tolerant design. Its fully redundant attitude sensor complement includes 16 coarse Sun sensors, a digital Sun sensor, 3 two-axis inertial reference units, 2 star trackers, and 4 guide telescopes. Attitude actuation is performed using 4 reaction wheels and 8 thrusters, and a single main engine nominally provides velocity-change thrust. The attitude control software has five nominal control modes-3 wheel-based modes and 2 thruster-based modes. A wheel-based Safehold running in the attitude control electronics box improves the robustness of the system as a whole. All six modes are designed on the same basic proportional-integral-derivative attitude error structure, with more robust modes setting their integral gains to zero. The paper details the mode designs and their uses.
The Evolution of Marketing in Education.
ERIC Educational Resources Information Center
Knight, Brent
1982-01-01
Looks at the progression of educational institutions through the five stages of Kotler's marketing process. Identifies anticipated changes and three activities critical for meeting the marketing challenge: research to predict consumer habits, attitudes, and needs; material and research development changes; and strict quality control and relevance…
Attributions and Attitudes of Mothers and Fathers in Italy
Bombi, Anna Silvia; Pastorelli, Concetta; Bacchini, Dario; Di Giunta, Laura; Miranda, Maria C.; Zelli, Arnaldo
2011-01-01
SYNOPSIS Objective The present study examined mean level similarities and differences as well as correlations between mothers’ and fathers’ attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. Design Interviews were conducted with both mothers and fathers in 177 Italian families from Rome and Naples. Results Fathers’ attributions reflected higher perceived control over failure than did mothers’ attributions, whereas mothers reported attitudes that were more progressive than did fathers. Only the difference in progressive attitudes remained significant after controlling for parents’ age, education, and possible social desirability bias. Site differences emerged for four of the seven attributions and attitudes examined; three remained significant after controlling for parents’ age, education, and possible social desirability bias. Medium effect sizes were found for concordance between parents in the same family for authoritarian attitudes and modernity of attitudes after controlling for parents’ age, education, and possible social desirability bias. Conclusions This work elucidates ways that parent gender and cultural context relate to attributions regarding parents’ success and failure in caregiving situations and to progressive versus authoritarian parenting attitudes. PMID:21927586
Attributions and Attitudes of Mothers and Fathers in Italy.
Bombi, Anna Silvia; Pastorelli, Concetta; Bacchini, Dario; Di Giunta, Laura; Miranda, Maria C; Zelli, Arnaldo
2011-07-01
OBJECTIVE: The present study examined mean level similarities and differences as well as correlations between mothers' and fathers' attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. DESIGN: Interviews were conducted with both mothers and fathers in 177 Italian families from Rome and Naples. RESULTS: Fathers' attributions reflected higher perceived control over failure than did mothers' attributions, whereas mothers reported attitudes that were more progressive than did fathers. Only the difference in progressive attitudes remained significant after controlling for parents' age, education, and possible social desirability bias. Site differences emerged for four of the seven attributions and attitudes examined; three remained significant after controlling for parents' age, education, and possible social desirability bias. Medium effect sizes were found for concordance between parents in the same family for authoritarian attitudes and modernity of attitudes after controlling for parents' age, education, and possible social desirability bias. CONCLUSIONS: This work elucidates ways that parent gender and cultural context relate to attributions regarding parents' success and failure in caregiving situations and to progressive versus authoritarian parenting attitudes.
NASA Astrophysics Data System (ADS)
Legault, Louise M. R.
1999-11-01
Developments in the Quebec educational system enabled us to evaluate the impact of a new educational environmental program (EEP) on a group of children enrolled in this program for the first time (i.e., the experimental group). This EEP comprised a formal curriculum and environmental activities. A control group of children was enrolled in schools where environmental issues were confined to the natural sciences subject. The goals of this study were threefold. The first goal was to evaluate the impact of an EEP on children's and parents' ecological knowledge, attitudes, motivation, and behaviors. The second goal was to investigate if a motivational model of ecological behaviors observed in adult populations could be replicated with children. Part of this goal also included the comparison of path analyses results across experimental conditions, independently for children and parents. The third goal was to identify more clearly what specific children's characteristics influenced parents' ecological attitudes and motivation. Included in this goal was the investigation of possible differences in the strength of associations between constructs in paths analyses conducted in the experimental and control groups of parents. Results suggested that children in the experimental group were more likely to ask teachers and parents for ecological information and presented a more self-determined motivational profile. Additional analyses revealed that children enrolled in an EEP performed ecological behaviors less for extrinsic motives. Level of knowledge, other attitudes and behavioral measures did not differ significantly between the two groups. Parents of children in the experimental group reported lower levels of satisfaction towards the environment and were more likely to get information on ecological issues and strategies from children. No other significant differences between groups of parents were found. Path analyses results suggested that parents' perceptions of children's provision of autonomy support and of ecological information, as well as, joint child/parent involvement in ecological activities favored parents' ecological attitudes and motivation. These results were consistent across the experimental and the control groups. Future studies are necessary to identify optimal intervention strategies devised to foster in people a sense of personal responsibility and self-determination that may propel them into action.
Racial/ethnic differences in midlife women's attitudes toward physical activity.
Im, Eun-Ok; Ko, Young; Hwang, Hyenam; Chee, Wonshik; Stuifbergen, Alexa; Walker, Lorraine; Brown, Adama
2013-01-01
Women's racial/ethnic-specific attitudes toward physical activity have been pointed out as a plausible reason for their low participation rates in physical activity. However, very little is actually known about racial/ethnic commonalities and differences in midlife women's attitudes toward physical activity. The purpose of this study was to explore commonalities and differences in midlife women's attitudes toward physical activity among 4 major racial/ethnic groups in the United States (whites, Hispanics, African Americans, and Asians). This was a secondary analysis of the qualitative data from a larger study that explored midlife women's attitudes toward physical activity. Qualitative data from 4 racial/ethnic-specific online forums among 90 midlife women were used for this study. The data were analyzed using thematic analysis, and themes reflecting commonalties and differences in the women's attitudes toward physical activity across the racial/ethnic groups were extracted. The themes reflecting the commonalities were: 1) physical activity is good for health, 2) not as active as I could be, 3) physical activity was not encouraged, 4) inherited diseases motivated participation in physical activity, and 5) lack of accessibility to physical activity. The themes reflecting the differences were: 1) physical activity as necessity or luxury, 2) organized versus natural physical activity, 3) individual versus family-oriented physical activity, and 4) beauty ideal or culturally accepted physical appearance. Developing an intervention that could change the social influences and environmental factors and address the women's racial/ethnic-specific attitudes would be a priority in increasing physical activity of racial/ethnic minority midlife women. © 2013 by the American College of Nurse-Midwives.
NASA Technical Reports Server (NTRS)
Helms, W. Jason; Pohlkamp, Kara M.
2011-01-01
The Space Shuttle does not dock at an exact 90 degrees to the International Space Station (ISS) x-body axis. This offset from 90 degrees, along with error sources within their respective attitude knowledge, causes the two vehicles to never completely agree on their attitude, even though they operate as a single, mated stack while docked. The docking offset can be measured in flight when both vehicles have good attitude reference and is a critical component in calculations to transfer attitude reference from one vehicle to another. This paper will describe how the docking offset and attitude reference errors between both vehicles are measured and how this information would be used to recover Shuttle attitude reference from ISS in the event of multiple failures. During STS-117, ISS on-board Guidance, Navigation and Control (GNC) computers began having problems and after several continuous restarts, the systems failed. The failure took the ability for ISS to maintain attitude knowledge. This paper will also demonstrate how with knowledge of the docking offset, the contingency procedure to recover Shuttle attitude reference from ISS was reversed in order to provide ISS an attitude reference from Shuttle. Finally, this paper will show how knowledge of the docking offset can be used to speed up attitude control handovers from Shuttle to ISS momentum management. By taking into account the docking offset, Shuttle can be commanded to hold a more precise attitude which better agrees with the ISS commanded attitude such that start up transients with the ISS momentum management controllers are reduced. By reducing start-up transients, attitude control can be transferred from Shuttle to ISS without the use of ISS thrusters saving precious on-board propellant, crew time and minimizing loads placed upon the mated stack.
Attitude control fault protection - The Voyager experience
NASA Technical Reports Server (NTRS)
Litty, E. C.
1980-01-01
The length of the Voyager mission and the communication delay caused by the distances involved made fault protection a necessary part of the Voyager Attitude and Articulation Control Subsystem (AACS) design. An overview of the Voyager attitude control fault protection is given and flight experiences relating to fault protection are provided.
Doubt in the Insula: Risk Processing in Obsessive-Compulsive Disorder
Luigjes, Judy; Figee, Martijn; Tobler, Philippe N.; van den Brink, Wim; de Kwaasteniet, Bart; van Wingen, Guido; Denys, Damiaan
2016-01-01
Extensive cleaning or checking of patients with obsessive-compulsive disorder (OCD) are often interpreted as strategies to avoid harm and as an expression of the widespread belief that OCD patients are more risk-averse. However, despite its clinical significance, the neural basis of risk attitude in OCD is unknown. Here, we investigated neural activity during risk processing using functional magnetic resonance imaging and simultaneously assessed risk attitude using a separate behavioral paradigm in OCD patients with different symptoms versus healthy controls (HCs). We found opposite insula responses to high versus low risk in OCD patients compared to HCs: a positive correlation between insula activity and risk-aversion in patients versus a negative correlation in controls. Although OCD patients overall were not more risk-averse than controls, there were differences between subgroups of OCD patients: patients with doubt/checking symptoms were more risk-averse than other patients. Taken together, OCD patients show a reversed pattern of risk processing by the insula compared to HCs. Moreover, the data suggest that increased activation of the insula signals an abnormal urge to avoid risks in the subpopulation of OCD patients with doubt and checking symptoms. These results indicate a role for the insula in excessive risk-avoidance relevant to OCD. PMID:27378883
Flight Dynamics Analysis Branch 2005 Technical Highlights
NASA Technical Reports Server (NTRS)
2005-01-01
This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 595, in support of flight projects and technology development initiatives in Fiscal Year (FY) 2005. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics including spacecraft navigation (autonomous and ground based); spacecraft trajectory design and maneuver planning; attitude analysis; attitude determination and sensor calibration; and attitude control subsystem (ACS) analysis and design. The FDAB currently provides support for missions and technology development projects involving NASA, other government agencies, academia, and private industry.
Magnetospheric Multiscale Mission Attitude Dynamics: Observations from Flight Data
NASA Technical Reports Server (NTRS)
Williams, Trevor; Shulman, Seth; Sedlak, Joseph E.; Ottenstein, Neil; Lounsbury, Brian
2016-01-01
The NASA Magnetospheric Multiscale mission, launched on Mar. 12, 2015, is flying four spinning spacecraft in highly elliptical orbits to study the magnetosphere of the Earth. Extensive attitude data is being collected, including spin rate, spin axis orientation, and nutation rate. The paper will discuss the various environmental disturbance torques that act on the spacecraft, and will describe the observed results of these torques. In addition, a slow decay in spin rate has been observed for all four spacecraft in the extended periods between maneuvers. It is shown that this despin is consistent with the effects of an additional disturbance mechanism, namely that produced by the Active Spacecraft Potential Control devices. Finally, attitude dynamics data is used to analyze a micrometeoroid/orbital debris impact event with MMS4 that occurred on Feb. 2, 2016.
2012-01-01
Background Social marketing campaigns offer a promising approach to the prevention of childhood obesity. Change4Life (C4L) is a national obesity prevention campaign in England. It included mass media coverage aiming to reframe obesity into a health issue relevant to all and provided the opportunity for parents to complete a brief questionnaire (‘How are the Kids’) and receive personalised feedback about their children’s eating and activity. Print and online C4L resources were available with guidance about healthy eating and physical activity. The study aims were to examine the impact of personalised feedback and print material from the C4L campaign on parents’ attitudes and behaviours about their children’s eating and activity in a community-based cluster-randomised controlled trial. Methods Parents of 5–11 year old children were recruited from 40 primary schools across England. Schools were randomised to intervention or control (‘usual care’). Basic demographic data and brief information about their attitudes to their children’s health were collected. Families in intervention schools were mailed the C4L print materials and the ‘How are the Kids’ questionnaire; those returning the questionnaire were sent personalised feedback and others received generic materials. Outcomes included awareness of C4L, attitudes to the behaviours recommended in C4L, parenting behaviours (monitoring and modelling), and child health behaviours (diet, physical activity and television viewing). Follow-up data were collected from parents by postal questionnaire after six months. Qualitative interviews were carried out with a subset of parents (n = 12). Results 3,774 families completed baseline questionnaires and follow-up data were obtained from 1,419 families (37.6%). Awareness was high in both groups at baseline (75%), but increased significantly in the intervention group by follow-up (96% vs. 87%). Few parents (5.2% of the intervention group) returned the questionnaire to get personalised feedback. There were few significant group differences in parental attitudes or parenting and child health behaviours at follow-up. Physical activity was rated as less important in the intervention group, but a significant group-by-socioeconomic status (SES) interaction indicated that this effect was confined to higher SES families. Similar interactions were also seen for physical activity monitoring and child television time; with adverse effects in higher SES families and no change in the lower SES families. Effects were little better in families that completed the questionnaire and received personalised feedback. At interview, acceptability of the intervention was modest, although higher in lower SES families. Conclusions The C4L campaign materials achieved increases in awareness of the campaign, but in this sample had little impact on attitudes or behaviour. Low engagement with the intervention appeared a key issue. Trial registration number Current Controlled Trials ISRCTN00791709. PMID:22672587
NASA Technical Reports Server (NTRS)
Li, Rongsheng (Inventor); Kurland, Jeffrey A. (Inventor); Dawson, Alec M. (Inventor); Wu, Yeong-Wei A. (Inventor); Uetrecht, David S. (Inventor)
2004-01-01
Methods and structures are provided that enhance attitude control during gyroscope substitutions by insuring that a spacecraft's attitude control system does not drive its absolute-attitude sensors out of their capture ranges. In a method embodiment, an operational process-noise covariance Q of a Kalman filter is temporarily replaced with a substantially greater interim process-noise covariance Q. This replacement increases the weight given to the most recent attitude measurements and hastens the reduction of attitude errors and gyroscope bias errors. The error effect of the substituted gyroscopes is reduced and the absolute-attitude sensors are not driven out of their capture range. In another method embodiment, this replacement is preceded by the temporary replacement of an operational measurement-noise variance R with a substantially larger interim measurement-noise variance R to reduce transients during the gyroscope substitutions.
Bryan, A D; Aiken, L S; West, S G
1996-09-01
A multicomponent intervention to increase condom use in sexually active young women was designed, implemented, and evaluated in a randomized experiment. Participants were 198 unmarried female college students (mean age = 18.6 years) who received a 1-session condom promotion intervention or a control (stress management) intervention. The condom promotion intervention led to increased self-reported condom use up to 6 months following intervention as well as positive changes in perceived benefits of condom use, affective attitudes toward condom use and condom users, perceived acceptance of sexuality, control over the sexual encounter, perceived self-efficacy for condom use, and intentions to use condoms. Mediational analysis illustrated the mechanisms of the condom promotion intervention effects, linking psychological constructs affected by the intervention (perceived benefits, acceptance of sexuality, control over the sexual encounter, attitudes toward condoms, and self-efficacy for condom use) to condom use intentions.
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Commander Ken Cockrell conducts window inspection, checking for leaks, in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- The STS-98 crew looks over components of the equipment already installed in the payload bay of orbiter Atlantis, which is in the Orbiter Processing Facility bay 3. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Pilot Mark Polansky inspects the window in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- The STS-98 crew looks over components of the equipment already installed in the payload bay of orbiter Atlantis, which is in the Orbiter Processing Facility bay 3. The crew is at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Commander Ken Cockrell conducts window inspection, checking for leaks, in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Working on the Orbiter Docking System of orbiter Atlantis are Mission Specialists Tom Jones (leaning over) and Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, STS-98 Pilot Mark Polansky inspects the window in the cockpit of Atlantis. He and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Working on the Orbiter Docking System of orbiter Atlantis are Mission Specialists Tom Jones (leaning over) and Robert Curbeam. They and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
Using marketing research methods to evaluate a stage-specific intervention.
Poscente, Neila; Rothstein, Marsha; Irvine, M Jane
2002-01-01
To show how marketing methods can be used to distribute and evaluate a health promotion intervention. Mass media promotion was used to communicate a physical activity resource. Brief telephone interviews were used to screen callers and recruit participants into a controlled trial. Follow-up was conducted 3 months later. Information was gained about the attitudes and motivation of callers. The majority of participants (study and control) made significant changes in their activity levels. The study demonstrated that even when mass media channels are used, market segmentation can be achieved and program evaluation conducted.
Knowledge, attitudes and practices on Schistosomiasis in sub-Saharan Africa: a systematic review.
Sacolo, Hlengiwe; Chimbari, Moses; Kalinda, Chester
2018-01-18
Schistosomiasis remains a global health problem with an estimated 250 million people in 78 countries infected, of whom 85% live in Sub-Saharan Africa. Preventive chemotherapy remains the key public health strategy to combat schistosomiasis worldwide. Recently the WHO emphasized on the use of integrative approaches in the control and elimination of schistosomiasis. However, a detailed understanding of sociocultural factors that may influence the uptake of the intended health activities and services is vital. Thus, our study sought to understand the knowledge, attitudes, perceptions, beliefs and practices about schistosomiasis in various communities in Sub-Saharan Africa. A systematic search of literature for the period 2006-2016 was done on Medline, PubMed, CINAHL, Psych info and Google Scholar using the following key words "Schistosomiasis, S. mansoni, S. haematobium, knowledge, attitudes, perceptions, beliefs and practices in Sub-Saharan Africa" in combination with Bolean operators (OR, AND). In this context, we reviewed studies conducted among school children, community members and caregivers of preschool children. Thematic analysis was utilised for the overall synthesis of the selected studies. This was done after reading the articles in depth. Themes were identified and examined for similarities, differences and contradictions. Gaps in schistosomiasis related knowledge and sociocultural barriers towards the uptake of preventive and treatment services among communities in Sub-Saharan Africa were identified. In addition to limited knowledge and negative attitudes, risky water related practices among community members, school children and caregivers of preschool children were identified as key factors promoting transmission of the disease. The study concluded that a comprehensive health education programme using contextual and standardised training tools may improve peoples' knowledge, attitudes and practices in relation to schistosomiasis prevention and control. Findings also highlight the significance of including caregivers in the planning and implementation schistosomiasis control programs targeting pre-school children.
Relative Attitude Determination of Earth Orbiting Formations Using GPS Receivers
NASA Technical Reports Server (NTRS)
Lightsey, E. Glenn
2004-01-01
Satellite formation missions require the precise determination of both the position and attitude of multiple vehicles to achieve the desired objectives. In order to support the mission requirements for these applications, it is necessary to develop techniques for representing and controlling the attitude of formations of vehicles. A generalized method for representing the attitude of a formation of vehicles has been developed. The representation may be applied to both absolute and relative formation attitude control problems. The technique is able to accommodate formations of arbitrarily large number of vehicles. To demonstrate the formation attitude problem, the method is applied to the attitude determination of a simple leader-follower along-track orbit formation. A multiplicative extended Kalman filter is employed to estimate vehicle attitude. In a simulation study using GPS receivers as the attitude sensors, the relative attitude between vehicles in the formation is determined 3 times more accurately than the absolute attitude.
On the generalization of attitude accessibility after repeated attitude expression
Spruyt, Adriaan; Fazio, Russell H.; Hermans, Dirk
2016-01-01
Abstract The more accessible an attitude is, the stronger is its influence on information processing and behavior. Accessibility can be increased through attitude rehearsal, but it remains unknown whether attitude rehearsal also affects the accessibility of related attitudes. To investigate this hypothesis, participants in an experimental condition repeatedly expressed their attitudes towards exemplars of several semantic categories during an evaluative categorization task. Participants in a control condition performed a non‐evaluative task with the same exemplars and evaluated unrelated attitude objects. After a 30‐minute interval, participants in the experimental condition were faster than controls to evaluate not only the original exemplars but also novel exemplars of the same categories. This finding suggests that the effect of attitude rehearsal on accessibility generalizes to attitudes towards untrained but semantically related attitude objects. © 2016 The Authors. European Journal of Social Psychology published by John Wiley & Sons, Ltd. PMID:28701803
Overview of the Miniature Sensor Technology Integration (MSTI) spacecraft attitude control system
NASA Technical Reports Server (NTRS)
Mcewen, Rob
1994-01-01
Msti2 is a small, 164 kg (362 lb), 3-axis stabilized, low-Earth-orbiting satellite whose mission is missile booster tracking. The spacecraft is actuated by 3 reaction wheels and 12 hot gas thrusters. It carries enough fuel for a projected life of 6 months. The sensor complement consists of a Horizon Sensor, a Sun Sensor, low-rate gyros, and a high rate gyro for despin. The total pointing control error allocation is 6 mRad (.34 Deg), and this is while tracking a target on the Earth's surface. This paper describes the Attitude Control System (ACS) algorithms which include the following: attitude acquisition (despin, Sun and Earth acquisition), attitude determination, attitude control, and linear stability analysis.
Tenenbaum, Harriet R; Capelos, Tereza; Lorimer, Jessica; Stocks, Thomas
2018-04-01
Inducing emotional reactions toward social groups can influence individuals' political tolerance. This study examines the influence of incidental fear and happiness on adolescents' tolerant attitudes and feelings toward young Muslim asylum seekers. In our experiment, 219 16- to 21-year-olds completed measures of prejudicial attitudes. After being induced to feel happiness, fear, or no emotion (control), participants reported their tolerant attitudes and feelings toward asylum-seeking young people. Participants assigned to the happiness condition demonstrated more tolerant attitudes toward asylum-seeking young people than did those assigned to the fear or control conditions. Participants in the control condition did not differ from participants in the fear condition. The participants in the happiness condition also had more positive feelings toward asylum-seeking young people than did participants in the control condition. The findings suggest that one way to increase positive attitudes toward asylum-seeking young people is to improve general emotional state.
Attributions and Attitudes of Mothers and Fathers in Sweden.
Sorbring, Emma; Gurdal, Sevtap
2011-07-01
OBJECTIVE: The present study examined mean level similarities and differences as well as correlations between mothers' and fathers' attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. DESIGN: Interviews were conducted with both mothers and fathers in 77 Swedish families. RESULTS: Fathers reported higher adult-controlled failure and child-controlled failure attributions than did mothers; these differences remained significant after controlling for parents' age, education, and possible social desirability bias. Significant positive correlations were found for mothers' and fathers' progressive attitudes, authoritarian attitudes, and modernity of attitudes after controlling for parents' age, education, and possible social desirability bias. CONCLUSIONS: We conclude that in Sweden fathers are more likely to attribute failures in caregiving situations both to themselves and to children than are mothers and that there is moderate concordance between fathers and mothers within the same family in progressive and authoritarian parenting attitudes.
IMP-J attitude control prelaunch analysis and operations plan
NASA Technical Reports Server (NTRS)
Hooper, H. L.; Mckendrew, J. B.; Repass, G. D.
1973-01-01
A description of the attitude control support being supplied for the Explorer 50 mission is given. Included in the document are descriptions of the computer programs being used to support attitude determination, prediction, and control for the mission and descriptions of the operating procedures that will be used to accomplish mission objectives.
The Relationship of Pupil Control Ideology to Students' Rights Attitudes.
ERIC Educational Resources Information Center
Jones, Lynn
As a result of increased court intervention in favor of students' rights, a review of a sample of teachers concerning their attitudes about student control was examined. Taking into consideration the teachers' attitudes concerning student rights, the Pupil Control Ideology test and the Students' Rights Acceptance Scale were used as measurement…
A design study for a simple-to-fly, constant attitude light aircraft
NASA Technical Reports Server (NTRS)
Smetana, F. O.; Humphreys, D. E.; Montoya, R. J.; Rickard, W. W.; Wilkinson, I. E.
1973-01-01
The activities during a four-year study by doctoral students to evolve in detail a design for a simple-to-fly, constant attitude light airplane are described. The study indicated that such aircraft could materially reduce the hazards to light airplane occupants which arise from the high pilot work load and poor visibility that occur during landing. Preliminary cost studies indicate that in volume production this system would increase the cost of the aircraft in roughly the same fashion that automatic transmission, power steering, power brakes, and cruise control increase the cost of a compact car.
La Paglia, Filippo; Rizzo, Rosalinda; La Barbera, Daniele
2011-01-01
The present study is aimed at analyzing the process of building and programming robots as a metacognitive tool of mathematics. Quantitative data from a study performed on a sample of students attending an Italian secondary school are described. Results showed that robotics activities may be used as a new metacognitive environment allowing students to improve their attitude towards mathematics, and to increase their attitude to reflect on themselves and on their own learning, and their higher-level control components, such as forecasting, planning, monitoring and evaluation exercises and problems related to implementation.
Spacecraft Hybrid (Mixed-Actuator) Attitude Control Experiences on NASA Science Missions
NASA Technical Reports Server (NTRS)
Dennehy, Cornelius J.
2014-01-01
There is a heightened interest within NASA for the design, development, and flight implementation of mixed-actuator hybrid attitude control systems for science spacecraft that have less than three functional reaction wheel actuators. This interest is driven by a number of recent reaction wheel failures on aging, but what could be still scientifically productive, NASA spacecraft if a successful hybrid attitude control mode can be implemented. Over the years, hybrid (mixed-actuator) control has been employed for contingency attitude control purposes on several NASA science mission spacecraft. This paper provides a historical perspective of NASA's previous engineering work on spacecraft mixed-actuator hybrid control approaches. An update of the current situation will also be provided emphasizing why NASA is now so interested in hybrid control. The results of the NASA Spacecraft Hybrid Attitude Control Workshop, held in April of 2013, will be highlighted. In particular, the lessons learned captured from that workshop will be shared in this paper. An update on the most recent experiences with hybrid control on the Kepler spacecraft will also be provided. This paper will close with some future considerations for hybrid spacecraft control.
Children's Attitudes toward Physical Activity and Self-Esteem.
ERIC Educational Resources Information Center
Ewy, Stan R.
This study was conducted to investigate attitudes toward physical activity and self-esteem of students (N=82) in grades three through five. The independent variables were gender, grade placement, and physical fitness. The dependent variables were scores from the Grade 3 Children's Attitudes Toward Physical Activity, the Revised Children's…
Attitudes toward Physical Activity among College Students.
ERIC Educational Resources Information Center
Mowatt, Marilyn; And Others
1988-01-01
Attitudes toward physical activity among 564 undergraduate and graduate students were primarily influenced by gender, year in school, activity class enrollment, and the passage of time. An experimental group, which received mini-lectures on the scientific bases of exercise, showed little significant change in attitude. The survey instrument is…
Parental Attitudes and Young People's Online Sexual Activities
ERIC Educational Resources Information Center
Sorbring, Emma; Hallberg, Jonas; Bohlin, Margareta; Skoog, Therése
2015-01-01
Parental attitudes towards young people's sexuality in traditional (i.e. non-online media) settings have been associated with young people's sexual activities. In this study, we explored the association between key parent and youth characteristics and parental attitudes towards young people's online sexual activities. We also examined the…
Inertia Estimation of Spacecraft Based on Modified Law of Conservation of Angular Momentum
NASA Astrophysics Data System (ADS)
Kim, Dong Hoon; Choi, Dae-Gyun; Oh, Hwa-Suk
2010-12-01
In general, the information of inertia properties is required to control a spacecraft. The inertia properties are changed by some activities such as consumption of propellant, deployment of solar panel, sloshing, etc. Extensive estimation methods have been investigated to obtain the precise inertia properties. The gyro-based attitude data including noise and bias needs to be compensated for improvement of attitude control accuracy. A modified estimation method based on the law of conservation of angular momentum is suggested to avoid inconvenience like filtering process for noiseeffect compensation. The conventional method is modified and beforehand estimated moment of inertia is applied to improve estimation efficiency of product of inertia. The performance of the suggested method has been verified for the case of STSAT-3, Korea Science Technology Satellite.
Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Woronowicz, M. S.
2011-05-20
The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cm{sup 3}. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may bemore » possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.« less
Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations
NASA Technical Reports Server (NTRS)
Woronowicz, M. S.
2010-01-01
The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cu cm. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may be possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.
ERIC Educational Resources Information Center
Kohler, Emmett T.; Christal, Melodie E.
Student and faculty attitudes about faculty evaluation and the relationship of the attitudes to the concept of locus of control were investigated. Student respondents consisted of 172 males and 256 females, and 108 faculty responses were received. The measure of locus of control closely resembles the Rotter Internal-External Control Scale. Student…
Comparison of Different Attitude Correction Models for ZY-3 Satellite Imagery
NASA Astrophysics Data System (ADS)
Song, Wenping; Liu, Shijie; Tong, Xiaohua; Niu, Changling; Ye, Zhen; Zhang, Han; Jin, Yanmin
2018-04-01
ZY-3 satellite, launched in 2012, is the first civilian high resolution stereo mapping satellite of China. This paper analyzed the positioning errors of ZY-3 satellite imagery and conducted compensation for geo-position accuracy improvement using different correction models, including attitude quaternion correction, attitude angle offset correction, and attitude angle linear correction. The experimental results revealed that there exist systematic errors with ZY-3 attitude observations and the positioning accuracy can be improved after attitude correction with aid of ground controls. There is no significant difference between the results of attitude quaternion correction method and the attitude angle correction method. However, the attitude angle offset correction model produced steady improvement than the linear correction model when limited ground control points are available for single scene.
Karadağ, Ayise; Hisar, Filiz; Göçmen Baykara, Zehra; Çalışkan, Nurcan; Karabulut, Hatice; Öztürk, Deniz
2015-01-01
The development of professional attitudes in nursing students is influenced by their learning experiences (knowledge, skills, and attitudes) and instructors' professional behaviors. Instructors can enhance students' professional attitude by organizing the training environment, being a role model, and providing counseling. This study was conducted as a tailoring intervention study over 4 years (2010-2013) examining 73 nursing students (34 intervention, 39 control) to determine the effect of training and counseling on nursing students' professional attitudes. Data were collected utilizing the Introductory Characteristics Form and the Instrument of Professional Attitude for Student Nurses. Intervention group students were provided training and counseling complementing their current education to develop their professional attitudes. Controls proceeded with their current education. Instrument for Professional Attitude for Student Nurses posttest scores of the intervention group were significantly higher than those of control group students. Furthermore, intervention group scores on all subscales other than "competence and continuous education" significantly increased after training. Controls showed no growth in professional attitudes, other than in "contribution to scientific knowledge." The training and counseling program had a positive influence on the professional attitudes of nursing students. Thus, providing tailored training and counseling associated to professionalism throughout the educational process at schools providing nursing training is recommended. Copyright © 2015 Elsevier Inc. All rights reserved.
The neural basis of implicit moral attitude--an IAT study using event-related fMRI.
Luo, Qian; Nakic, Marina; Wheatley, Thalia; Richell, Rebecca; Martin, Alex; Blair, R James R
2006-05-01
Recent models of morality have suggested the importance of affect-based automatic moral attitudes in moral reasoning. However, previous investigations of moral reasoning have frequently relied upon explicit measures that are susceptible to voluntary control. To investigate participant's automatic moral attitudes, we used a morality Implicit Association Test (IAT). Participants rated the legality of visually depicted legal and illegal behaviors of two different intensity levels (e.g., high intensity illegal = interpersonal violence; low intensity illegal = vandalism) both when the target concept (e.g., illegal) was behaviorally paired with an associated attribute (e.g., bad; congruent condition) or an unassociated attribute (e.g., good; incongruent condition). Behaviorally, an IAT effect was shown; RTs were faster in the congruent rather than incongruent conditions. At the neural level, implicit moral attitude, as indexed by increased BOLD response as a function of stimulus intensity, was associated with increased activation in the right amygdala and the ventromedial orbitofrontal cortex. In addition, performance on incongruent trials relative to congruent trials was associated with increased activity in the right ventrolateral prefrontal cortex (BA 47), left subgenual cingulate gyrus (BA 25), bilateral premotor cortex (BA 6) and the left caudate. The functional contributions of these regions in moral reasoning are discussed.
Hu, Chuanlai; Ye, Dongqing; Li, Yingchun; Huang, Yongling; Li, Li; Gao, Yongqing; Wang, Sufang
2010-02-01
To evaluate the impact of nutrition education in kindergartens and to promote healthy dietary habits in children. Prospective cohort study. Four kindergartens with 1252 children were randomized to the intervention group and three with 850 children to the control group. The personal nutritional knowledge, attitudes and dietary behaviours of the parents were also investigated. Each month, children and parents in the intervention group participated in nutrition education activities. The main outcome measures were anthropometrics and diet-related behaviours of the children and the nutritional knowledge and attitudes of the parents at baseline, 6 months (mid-term) and 1 year (post-test). Baseline demographic and socio-economic characteristics were also collected. Seven kindergartens from Hefei, the capital city of Anhui Province, eastern China. Two thousand one hundred and two 4- to 6-year-old pre-schoolers from seven kindergartens participated. The prevalence of children's unhealthy diet-related behaviours decreased significantly and good lifestyle behaviours increased in the group receiving nutrition education compared with controls. Parental eating habits and attitudes to planning their children's diets also changed appreciably in the intervention group compared with the control group (P < 0.05). However, there were no statistically significant differences in children's height, weight, height-for-age Z-score or weight-for-age Z-score between the two groups. Kindergarten-based nutrition education improves pre-schoolers' lifestyle behaviours and brings about beneficial changes in parents' attitudes to planning their children's diets and their own personal eating habits.
Attitude determination with three-axis accelerometer for emergency atmospheric entry
NASA Technical Reports Server (NTRS)
Garcia-Llama, Eduardo (Inventor)
2012-01-01
Two algorithms are disclosed that, with the use of a 3-axis accelerometer, will be able to determine the angles of attack, sideslip and roll of a capsule-type spacecraft prior to entry (at very high altitudes, where the atmospheric density is still very low) and during entry. The invention relates to emergency situations in which no reliable attitude and attitude rate are available. Provided that the spacecraft would not attempt a guided entry without reliable attitude information, the objective of the entry system in such case would be to attempt a safe ballistic entry. A ballistic entry requires three controlled phases to be executed in sequence: First, cancel initial rates in case the spacecraft is tumbling; second, maneuver the capsule to a heat-shield-forward attitude, preferably to the trim attitude, to counteract the heat rate and heat load build up; and third, impart a ballistic bank or roll rate to null the average lift vector in order to prevent prolonged lift down situations. Being able to know the attitude, hence the attitude rate, will allow the control system (nominal or backup, automatic or manual) to cancel any initial angular rates. Also, since a heat-shield forward attitude and the trim attitude can be specified in terms of the angles of attack and sideslip, being able to determine the current attitude in terms of these angles will allow the control system to maneuver the vehicle to the desired attitude. Finally, being able to determine the roll angle will allow for the control of the roll ballistic rate during entry.
Touchless attitude correction for satellite with constant magnetic moment
NASA Astrophysics Data System (ADS)
Ao, Hou-jun; Yang, Le-ping; Zhu, Yan-wei; Zhang, Yuan-wen; Huang, Huan
2017-09-01
Rescue of satellite with attitude fault is of great value. Satellite with improper injection attitude may lose contact with ground as the antenna points to the wrong direction, or encounter energy problems as solar arrays are not facing the sun. Improper uploaded command may set the attitude out of control, exemplified by Japanese Hitomi spacecraft. In engineering practice, traditional physical contact approaches have been applied, yet with a potential risk of collision and a lack of versatility since the mechanical systems are mission-specific. This paper puts forward a touchless attitude correction approach, in which three satellites are considered, one having constant dipole and two having magnetic coils to control attitude of the first. Particular correction configurations are designed and analyzed to maintain the target's orbit during the attitude correction process. A reference coordinate system is introduced to simplify the control process and avoid the singular value problem of Euler angles. Based on the spherical triangle basic relations, the accurate varying geomagnetic field is considered in the attitude dynamic mode. Sliding mode control method is utilized to design the correction law. Finally, numerical simulation is conducted to verify the theoretical derivation. It can be safely concluded that the no-contact attitude correction approach for the satellite with uniaxial constant magnetic moment is feasible and potentially applicable to on-orbit operations.
NASA Astrophysics Data System (ADS)
Gaston, Joseph Pickett
This quantitative study examined the effects of collaborative video production (CVP) on the attitudes and conceptual understanding of sixth-grade science students at a public middle school in the Southeastern United States. This study followed the nonequivalent control group design, as described by Campbell and Stanley (1963). The study involved four classes of sixth-grade students. The two control classes were taught the science concept by the cooperating teacher through direct instruction, and the two experimental classes learned the science concept through the CVP project. Pre- and posttests were administered to all students, as well as two pre- and post-surveys measuring student attitudes towards science and technology. Analysis of covariance (ANCOVA) with the pretest scores as the covariate (Xc) was conducted with the posttest and post-survey data to determine if a significant difference existed in scores between the two groups. In each case, no significant difference was found. The results of this study suggest that CVP was as effective at conveying conceptual understanding to sixth-grade science students as direct instruction. Although not significant, the study also showed that mean scores of students' attitudes towards science and technology increased from pre-surveys to post-surveys for those who participated in the CVP activity. These findings suggest that the treatment contributed to an increase in participants' attitudes and towards technology and the academic subject. No such increase in mean post-survey scores existed for students receiving direct instruction.
Sensor fault detection and recovery in satellite attitude control
NASA Astrophysics Data System (ADS)
Nasrolahi, Seiied Saeed; Abdollahi, Farzaneh
2018-04-01
This paper proposes an integrated sensor fault detection and recovery for the satellite attitude control system. By introducing a nonlinear observer, the healthy sensor measurements are provided. Considering attitude dynamics and kinematic, a novel observer is developed to detect the fault in angular rate as well as attitude sensors individually or simultaneously. There is no limit on type and configuration of attitude sensors. By designing a state feedback based control signal and Lyapunov stability criterion, the uniformly ultimately boundedness of tracking errors in the presence of sensor faults is guaranteed. Finally, simulation results are presented to illustrate the performance of the integrated scheme.
Autonomous spacecraft attitude control using magnetic torquing only
NASA Technical Reports Server (NTRS)
Musser, Keith L.; Ebert, Ward L.
1989-01-01
Magnetic torquing of spacecraft has been an important mechanism for attitude control since the earliest satellites were launched. Typically a magnetic control system has been used for precession/nutation damping for gravity-gradient stabilized satellites, momentum dumping for systems equipped with reaction wheels, or momentum-axis pointing for spinning and momentum-biased spacecraft. Although within the small satellite community there has always been interest in expensive, light-weight, and low-power attitude control systems, completely magnetic control systems have not been used for autonomous three-axis stabilized spacecraft due to the large computational requirements involved. As increasingly more powerful microprocessors have become available, this has become less of an impediment. These facts have motivated consideration of the all-magnetic attitude control system presented here. The problem of controlling spacecraft attitude using only magnetic torquing is cast into the form of the Linear Quadratic Regulator (LQR), resulting in a linear feedback control law. Since the geomagnetic field along a satellite trajectory is not constant, the system equations are time varying. As a result, the optimal feedback gains are time-varying. Orbit geometry is exploited to treat feedback gains as a function of position rather than time, making feasible the onboard solution of the optimal control problem. In simulations performed to date, the control laws have shown themselves to be fairly robust and a good candidate for an onboard attitude control system.
Doherty, Julie; Giles, Melanie; Gallagher, Alison M; Simpson, Ellen Elizabeth Anne
2018-03-01
Although physical activity guidelines recommend muscle-strengthening activities (MSA), public health initiatives tend to focus on increasing aerobic activity and fail to mention MSA. This study sought to identify the issues influencing pre-, peri- and post-menopausal women's intentions to perform MSA with a view to informing future interventions for these populations. Mixed methods guided by the Theory of Planned Behaviour (TPB) were used to explore factors that influence women's intentions to perform MSA. In stage one, 34 women participated in either a focus group or interview. Discussions were transcribed verbatim and analysed based on menopausal status using a deductive approach. In stage two, 186 women (M = 47 years, SD = 9) completed a questionnaire to assess participant demographics, levels of MSA, affective and instrumental attitudes, injunctive and descriptive norms, self-efficacy and perceived behavioural control. Quantitative data were analysed using descriptive statistics, bivariate correlations, regression analyses and analysis of variances. Behavioural beliefs were: improved muscular health; psychological benefits; improved body shape. Normative beliefs were: health professionals; family members; work colleagues. Control beliefs were: equipment; motivation; time constraints; knowledge; physical capability; fear of judgement. However, these beliefs were not well established. Self-efficacy was the strongest predictor of intentions (spc 2 = 0.11) followed by affective attitudes (spc 2 = 0.09), with no significant differences on TPB variables between groups. If rising rates of musculoskeletal conditions in women are to be prevented, there is an urgent need to increase women's knowledge of recommended levels of muscle strengthening, with a view to promoting positive attitudes and enhancing women's sense of self-efficacy across all menopausal phases. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.
Pace, Ugo; D'Urso, Giulio; Zappulla, Carla
2018-02-01
In the present study, we examined from a longitudinal perspective the relationship between parental (both maternal and paternal) psychological control, perceived peer support, and negative eating attitudes and behaviors, focusing on the moderating role that perceived peer support may play in the relationship between parental psychological control in early adolescence and negative eating attitudes and behaviors in late adolescence. In Wave 1, participants were 507 adolescents (249 boys and 258 girls) aged from 14 to 15 years (M = 14.76; SD = 0.63). Three years later (Wave 2), the same adolescents participated again in the study (M = 17.88 years; SD = 0.57). Regression analyses displayed that paternal, but not maternal, achievement-oriented psychological control during early adolescence positively predicted negative eating attitudes and behaviors in late adolescence, whereas perceived peer support negatively predicted negative eating attitudes and behaviors. Results also showed a moderator effect of perceived peer support in the relationship between father's psychological control and negative eating attitudes and behaviors, such that at higher levels of paternal achievement-oriented psychological control, negative eating attitudes and behaviors tended to be higher when perceived peer support was low and to be lower when perceived peer support was high. Copyright © 2017. Published by Elsevier Ltd.
Multivariable control theory applied to hierarchial attitude control for planetary spacecraft
NASA Technical Reports Server (NTRS)
Boland, J. S., III; Russell, D. W.
1972-01-01
Multivariable control theory is applied to the design of a hierarchial attitude control system for the CARD space vehicle. The system selected uses reaction control jets (RCJ) and control moment gyros (CMG). The RCJ system uses linear signal mixing and a no-fire region similar to that used on the Skylab program; the y-axis and z-axis systems which are coupled use a sum and difference feedback scheme. The CMG system uses the optimum steering law and the same feedback signals as the RCJ system. When both systems are active the design is such that the torques from each system are never in opposition. A state-space analysis was made of the CMG system to determine the general structure of the input matrices (steering law) and feedback matrices that will decouple the axes. It is shown that the optimum steering law and proportional-plus-rate feedback are special cases. A derivation of the disturbing torques on the space vehicle due to the motion of the on-board television camera is presented. A procedure for computing an upper bound on these torques (given the system parameters) is included.
ERIC Educational Resources Information Center
Allen, Rodney F.
This activity is one of a series of 17 teacher-developed instructional activities for geography at the secondary-grade level described in SO 009 140. The activity investigates the rationale and means for including attitudes, feelings, and emotions in the environmental education curriculum. Explanation is given about the role of attitudes and…
NASA Technical Reports Server (NTRS)
1976-01-01
The six themes identified by the Workshop have many common navigation guidance and control needs. All the earth orbit themes have a strong requirement for attitude, figure and stabilization control of large space structures, a requirement not currently being supported. All but the space transportation theme have need for precision pointing of spacecraft and instruments. In addition all the themes have requirements for increasing autonomous operations for such activities as spacecraft and experiment operations, onboard mission modification, rendezvous and docking, spacecraft assembly and maintenance, navigation and guidance, and self-checkout, test and repair. Major new efforts are required to conceptualize new approaches to large space antennas and arrays that are lightweight, readily deployable, and capable of precise attitude and figure control. Conventional approaches offer little hope of meeting these requirements. Functions that can benefit from increasing automation or autonomous operations are listed.
Singularity and steering logic for control moment gyros on flexible space structures
NASA Astrophysics Data System (ADS)
Hu, Quan; Guo, Chuandong; Zhang, Jun
2017-08-01
Control moment gyros (CMGs) are a widely used device for generating control torques for spacecraft attitude control without expending propellant. Because of its effectiveness and cleanness, it has been considered to be mounted on a space structure for active vibration suppression. The resultant system is the so-called gyroelastic body. Since CMGs could exert both torque and modal force to the structure, it can also be used to simultaneously achieve attitude maneuver and vibration reduction of a flexible spacecraft. In this paper, we consider the singularity problem in such application of CMGs. The dynamics of an unconstrained gyroelastic body is established, from which the output equations of the CMGs are extracted. Then, torque singular state and modal force singular state are defined and visualized to demonstrate the singularity. Numerical examples of several typical CMGs configurations on a gyroelastic body are given. Finally, a steering law allowing output error is designed and applied to the vibration suppression of a plate with distributed CMGs.
Boaz, Annette; Biri, Despina; McKevitt, Christopher
2016-06-01
The policy imperative to engage the public and patients in research can be seen as part of a wider shift in the research environment. This study addresses the question: Has there been a shift in attitudes to Patient and Public Involvement (PPI) and Public Engagement in Science (PES) amongst researchers? Attitudes to PPI and PES within a cluster of three NIHR supported Biomedical Research Centres were explored through in-depth interviews with 19 researchers. Participants distinguished PPI (as an activity involving patients and carers in research projects and programmes) from PES (as an activity that aims to communicate research findings to the public, engage the public with broader issues of science policy or promote a greater understanding of the role of science in society). While participants demonstrated a range of attitudes to these practices, they shared a resistance to sharing power and control of the research process with the public and patients. While researchers were prepared to engage with the public and patients and listed the advantages of engagement, the study revealed few differences in their underlying attitudes towards the role of society in science (and science in society) to those reported in previous studies. To the participants science remains the preserve of scientists, with patients and the public invited to 'tinker at the edges'. © 2014 The Authors Health Expectations Published by John Wiley & Sons Ltd.
Design and Stability of an On-Orbit Attitude Control System Using Reaction Control Thrusters
NASA Technical Reports Server (NTRS)
Hall, Robert A.; Hough, Steven; Orphee, Carolina; Clements, Keith
2016-01-01
NASA is providing preliminary design and requirements for the Space Launch System Exploration Upper Stage (EUS). The EUS will provide upper stage capability for vehicle ascent as well as on-orbit control capability. Requirements include performance of on-orbit burn to provide Orion vehicle with escape velocity. On-orbit attitude control is accommodated by a on-off Reaction Control System (RCS). Paper provides overview of approaches for design and stability of an attitude control system using a RCS.
NASA Astrophysics Data System (ADS)
Heron, Lory Elen
This study investigated the premise that the use of constructivist teaching strategies (independent variable) in high school science classrooms can cultivate positive attitudes toward science (dependent variable) in high school students. Data regarding the relationship between the use of constructivist strategies and change in student attitude toward science were collected using the Science Attitude Assessment Tool (SAAT) (Heron & Beauchamp, 1996). The format of this study used the pre-test, post-test, control group-experimental group design. The subjects in the study were high school students enrolled in biology, chemistry, or environmental science courses in two high schools in the western United States. Ten teachers and twenty-eight classes, involving a total of 249 students participated in the study. Six experimental group teachers and four control group teachers were each observed an average of six times using the Science Observation Guide (Chapman, 1995) to measure the frequency of observed constructivist behaviors. The mean for the control group teachers was 12.89 and the mean for experimental group teachers was 20.67; F(1, 8) = 16.2, p =.004, revealing teaching behaviors differed significantly between the two groups. After a four month experimental period, the pre-test and post-test SAAT scores were analyzed. Students received a score for their difference in positive attitude toward science. The null hypothesis stating there would be no change in attitude toward science as a subject, between students exposed to constructivist strategies, and students not exposed to constructivist strategies was rejected F(1, 247) = 8.04, p =.005. The control group had a generally higher reported grade in their last science class than the experimental group, yet the control group attitude toward science became more negative (-1.18) while attitude toward science in the experimental group became more positive (+1.34) after the four-month period. An analysis of positive attitude toward science vs. gender was undertaken. An initial significant difference in positive attitude toward science between females and males in the experimental group was established (p =.05). There was no significant difference in positive attitude toward science between those same females and males after the experimental period. Consistent with other results, attitudes toward science for both males and females in the control group became less positive after the study, while males and females in the experimental group had a more positive attitude toward science after four months of using constructivist strategies. Looking at females only, the control group started out with a significantly more positive attitude toward science (mean = 43.40) compared to the experimental group (mean = 39.26, p =.0261). Although a significant difference in positive attitude between females in both groups was not found after the treatment period, the mean attitude score for females in the experimental group increased 2.044, while the mean attitude score for females in the control group decreased by 1.750. Constructivist strategies and their relationship with fostering positive attitudes toward science, might prove a viable solution for addressing the major concern of gender equity and enrollment in higher level science and mathematics courses.
AE-C attitude determination and control prelaunch analysis and operations plan
NASA Technical Reports Server (NTRS)
Werking, R. D.; Headrick, R. D.; Manders, C. F.; Woolley, R. D.
1973-01-01
A description of attitude control support being supplied by the Mission and Data Operations Directorate is presented. Included are descriptions of the computer programs being used to support the missions for attitude determination, prediction, and control. In addition, descriptions of the operating procedures which will be used to accomplish mission objectives are provided.
Zou, An-Min; Dev Kumar, Krishna; Hou, Zeng-Guang
2010-09-01
This paper investigates the problem of output feedback attitude control of an uncertain spacecraft. Two robust adaptive output feedback controllers based on Chebyshev neural networks (CNN) termed adaptive neural networks (NN) controller-I and adaptive NN controller-II are proposed for the attitude tracking control of spacecraft. The four-parameter representations (quaternion) are employed to describe the spacecraft attitude for global representation without singularities. The nonlinear reduced-order observer is used to estimate the derivative of the spacecraft output, and the CNN is introduced to further improve the control performance through approximating the spacecraft attitude motion. The implementation of the basis functions of the CNN used in the proposed controllers depends only on the desired signals, and the smooth robust compensator using the hyperbolic tangent function is employed to counteract the CNN approximation errors and external disturbances. The adaptive NN controller-II can efficiently avoid the over-estimation problem (i.e., the bound of the CNNs output is much larger than that of the approximated unknown function, and hence, the control input may be very large) existing in the adaptive NN controller-I. Both adaptive output feedback controllers using CNN can guarantee that all signals in the resulting closed-loop system are uniformly ultimately bounded. For performance comparisons, the standard adaptive controller using the linear parameterization of spacecraft attitude motion is also developed. Simulation studies are presented to show the advantages of the proposed CNN-based output feedback approach over the standard adaptive output feedback approach.
Increasing Parent Involvement among Head Start Families: A Randomized Control Group Study
ERIC Educational Resources Information Center
DeLoatche, Kendall Jeffries; Bradley-Klug, Kathy L.; Ogg, Julia; Kromrey, Jeffrey D.; Sundman-Wheat, Ashley N.
2015-01-01
Parent involvement (PI) during preschool has been linked with strong pre-literacy skills, acquisition of mathematical skills, well-developed social skills, and positive attitudes toward school. Parents' active involvement in their children's learning is a recommended strategy in engaging families in children's education experiences. The purpose of…
A deorbiter CubeSat for active orbital debris removal
NASA Astrophysics Data System (ADS)
Hakima, Houman; Bazzocchi, Michael C. F.; Emami, M. Reza
2018-05-01
This paper introduces a mission concept for active removal of orbital debris based on the utilization of the CubeSat form factor. The CubeSat is deployed from a carrier spacecraft, known as a mothership, and is equipped with orbital and attitude control actuators to attach to the target debris, stabilize its attitude, and subsequently move the debris to a lower orbit where atmospheric drag is high enough for the bodies to burn up. The mass and orbit altitude of debris objects that are within the realms of the CubeSat's propulsion capabilities are identified. The attitude control schemes for the detumbling and deorbiting phases of the mission are specified. The objective of the deorbiting maneuver is to decrease the semi-major axis of the debris orbit, at the fastest rate, from its initial value to a final value of about 6471 km (i.e., 100 km above Earth considering a circular orbit) via a continuous low-thrust orbital transfer. Two case studies are investigated to verify the performance of the deorbiter CubeSat during the detumbling and deorbiting phases of the mission. The baseline target debris used in the study are the decommissioned KOMPSAT-1 satellite and the Pegasus rocket body. The results show that the deorbiting times for the target debris are reduced significantly, from several decades to one or two years.
Attitudes and beliefs as verbal behavior
Guerin, Bernard
1994-01-01
Attitudes and beliefs are analyzed as verbal behavior. It is argued that shaping by a verbal community is an essential part of the formation and maintenance of both attitudes and beliefs, and it is suggested that verbal communities mediate the important shift in control from events in the environment (attitudes and beliefs as tacts) to control by other words (attitudes and beliefs as intraverbals). It appears that both attitudes and beliefs are constantly being socially negotiated through autoclitic functions. That is, verbal communities reinforce (a) reporting general rather than specific attitudes and beliefs, (b) presentation of intraverbals as if they were tacts, and (c) presentation of beliefs as if they were attitudes. Consistency among and between attitudes, beliefs, and behavior is also contingent upon the reinforcing practices of verbal communities. Thus, attitudes and beliefs can be studied as social behavior rather than as private, cognitive processes. PMID:22478181
Gefeller, Olaf; Li, Jiang; Uter, Wolfgang; Pfahlberg, Annette B
2014-05-05
Public health campaigns have improved knowledge on UVR-associated skin cancer risk and increased sun protection awareness. However, tanned skin is still a common beauty ideal. The relationship between knowledge, attitudes and protective behavior is not fully understood yet. A population-based survey was thus performed in the district of Erlangen involving 2,619 parents of 3- to 6-year old children. By means of a self-administered standardized questionnaire parental knowledge about risk factors for skin cancer, their attitudes towards tanning and details of protective measures taken for their children were assessed. The study analyzed specifically the impact of parental tanning attitudes on sun-protective measures for their children while controlling for parental knowledge about skin cancer risk factors. While parental knowledge was significantly (inversely) associated with agreement to the statement "Tanned skin is healthy skin", this was not the case for "Tanning makes me look better". Overall, tanning affirmative attitudes were inversely associated with protective measures taken for the children, whereas parental knowledge had a positive impact on sun protection at the beach only. Multivariable analyses provided evidence for an effect of parental attitude on protective behavior independent of parental knowledge. Tanning attitudes and tanned skin as the misguided ideal of beauty need to be addressed in future public health campaigns to enhance the effectiveness of preventive activities in changing sun protective behavior.
Adolescents' Views on Active and Non-Active Videogames: A Focus Group Study.
Simons, Monique; de Vet, Emely; Hoornstra, Sjoukje; Brug, Johannes; Seidell, Jaap; Chinapaw, Mai
2012-06-01
Active games require whole-body movement and may be an innovative tool to substitute sedentary pastime with more active time and may therefore contribute to adolescents' health. To inform strategies aimed at reducing sedentary behavior by replacing non-active with active gaming, perceptions and context of active and non-active gaming are explored. Six focus groups were conducted with adolescents 12-16 years old representing a range of education levels. A semistructured question route was used containing questions about perceptions and the context of gaming. The adolescents had positive attitudes toward active gaming, especially the social interactive aspect, which was greatly appreciated. A substantial number of adolescents enjoyed non-active games more than active ones, mainly because of better game controls and more diversity in non-active games. Active games were primarily played when there was a social gathering. Few game-related rules and restrictions at home were reported. Given the positive attitudes of adolescents and the limited restrictions for gaming at home, active videogames may potentially be used in a home setting as a tool to reduce sedentary behavior. However, to make active games as appealing as non-active games, attention should be paid to the quality, diversity, and sustainability of active games, as these aspects are currently inferior to those of traditional non-active games.
Attitude coordination of multi-HUG formation based on multibody system theory
NASA Astrophysics Data System (ADS)
Xue, Dong-yang; Wu, Zhi-liang; Qi, Er-mai; Wang, Yan-hui; Wang, Shu-xin
2017-04-01
Application of multiple hybrid underwater gliders (HUGs) is a promising method for large scale, long-term ocean survey. Attitude coordination has become a requisite for task execution of multi-HUG formation. In this paper, a multibody model is presented for attitude coordination among agents in the HUG formation. The HUG formation is regarded as a multi-rigid body system. The interaction between agents in the formation is described by artificial potential field (APF) approach. Attitude control torque is composed of a conservative torque generated by orientation potential field and a dissipative term related with angular velocity. Dynamic modeling of the multibody system is presented to analyze the dynamic process of the HUG formation. Numerical calculation is carried out to simulate attitude synchronization with two kinds of formation topologies. Results show that attitude synchronization can be fulfilled based on the multibody method described in this paper. It is also indicated that different topologies affect attitude control quality with respect to energy consumption and adjusting time. Low level topology should be adopted during formation control scheme design to achieve a better control effect.
Adaptive attitude control and momentum management for large-angle spacecraft maneuvers
NASA Technical Reports Server (NTRS)
Parlos, Alexander G.; Sunkel, John W.
1992-01-01
The fully coupled equations of motion are systematically linearized around an equilibrium point of a gravity gradient stabilized spacecraft, controlled by momentum exchange devices. These equations are then used for attitude control system design of an early Space Station Freedom flight configuration, demonstrating the errors caused by the improper approximation of the spacecraft dynamics. A full state feedback controller, incorporating gain-scheduled adaptation of the attitude gains, is developed for use during spacecraft on-orbit assembly or operations characterized by significant mass properties variations. The feasibility of the gain adaptation is demonstrated via a Space Station Freedom assembly sequence case study. The attitude controller stability robustness and transient performance during gain adaptation appear satisfactory.
Tethered gravity laboratories study
NASA Technical Reports Server (NTRS)
Lucchetti, F.
1990-01-01
The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.
Damping SOFIA: passive and active damping for the Stratospheric Observatory for Infrared Astronomy
NASA Astrophysics Data System (ADS)
Maly, Joseph R.; Keas, Paul J.; Glaese, Roger M.
2001-07-01
The Stratospheric Observatory For Infrared Astronomy, SOFIA is being developed by NASA and the German space agency, Deutschen Zentrum fur Luft- und Raumfahrt (DLR), with an international contractor team. The 2.5-meter reflecting telescope of SOFIA will be the world's largest airborne telescope. Flying in an open cavity on a modified 747 aircraft, SOFIA will perform infrared astronomy while cruising at 41,000 feet and while being buffeted by a 550- mile-per-hour slipstream. A primary system requirement of SOFIA is tracking stability of 0.2 arc-seconds, and a 3-axis pointing control model has been used to evaluate the feasibility of achieving this kind of stability. The pointing control model shows that increased levels of damping in certain elastic modes of the telescope assembly will help achieve the tracking stability goal and also expand the bandwidth of the attitude controller. This paper describes the preliminary work that has been done to approximate the reduction in image motion yielded by various structure configurations that use reaction masses to attenuate the flexible motions of the telescope structure. Three approaches are considered: passive tuned-mass dampers, active-mass dampers, and attitude control with reaction-mass actuators. Expected performance improvements for each approach, and practical advantages and disadvantages associated with each are presented.
On-orbit experience with the HEAO attitude control subsystem
NASA Technical Reports Server (NTRS)
Hoffman, D. P.; Berkery, E. A.
1978-01-01
The first satellite (HEAO-1) in the High Energy Astronomy Observatory Program series was launched successfully on Aug. 12, 1977. To date it has completed over nine months of orbital operation in a science data gathering mode. During this period all attitude control modes have been exercised and all primary mission objectives have been achieved. This paper highlights the characteristics of the attitude control subsystem design and compares the predicted performance with the actual flight operations experience. Environmental disturbance modeling, component hardware/software characteristics, and overall attitude control performance are reviewed and are found to compare very well with the prelaunch analytical predictions. Brief comments are also included regarding the operations aspects of the attitude control subsystem. The experience in this regard demonstrates the effectiveness of the design flexibility afforded by the presence of a general purpose digital processor in the subsystem flight hardware implementation.
Implicit attitudes towards smoking predict long-term relapse in abstinent smokers.
Spruyt, Adriaan; Lemaigre, Valentine; Salhi, Bihiyga; Van Gucht, Dinska; Tibboel, Helen; Van Bockstaele, Bram; De Houwer, Jan; Van Meerbeeck, Jan; Nackaerts, Kristiaan
2015-07-01
It has previously been argued that implicit attitudes toward substance-related cues drive addictive behavior. Nevertheless, it remains an open question whether behavioral markers of implicit attitude activation can be used to predict long-term relapse. The main objective of this study was to examine the relationship between implicit attitudes toward smoking-related cues and long-term relapse in abstaining smokers. Implicit attitudes toward smoking-related cues were assessed by means of the Implicit Association Test (IAT) and the evaluative priming task (EPT). Both measures were completed by a group of smokers who volunteered to quit smoking (patient group) and a group of nonsmokers (control group). Participants in the patient group completed these measures twice: once prior to smoking cessation and once after smoking cessation. Relapse was assessed by means of short telephone survey, 6 months after completion of the second test session. EPT scores obtained prior to smoking cessation were related to long-term relapse and correlated with self-reported nicotine dependence as well as daily cigarette consumption. In contrast, none of the behavioral outcome measures were found to correlate with the IAT scores. These findings corroborate the idea that implicit attitudes toward substance-related cues are critically involved in long-term relapse. A potential explanation for the divergent findings obtained with the IAT and EPT is provided.
NASA Astrophysics Data System (ADS)
Tchernykh, Valerij; Dyblenko, Sergej; Janschek, Klaus; Seifart, Klaus; Harnisch, Bernd
2005-08-01
The cameras commonly used for Earth observation from satellites require high attitude stability during the image acquisition. For some types of cameras (high-resolution "pushbroom" scanners in particular), instantaneous attitude changes of even less than one arcsecond result in significant image distortion and blurring. Especially problematic are the effects of high-frequency attitude variations originating from micro-shocks and vibrations produced by the momentum and reaction wheels, mechanically activated coolers, and steering and deployment mechanisms on board. The resulting high attitude-stability requirements for Earth-observation satellites are one of the main reasons for their complexity and high cost. The novel SmartScan imaging concept, based on an opto-electronic system with no moving parts, offers the promise of high-quality imaging with only moderate satellite attitude stability. SmartScan uses real-time recording of the actual image motion in the focal plane of the camera during frame acquisition to correct the distortions in the image. Exceptional real-time performances with subpixel-accuracy image-motion measurement are provided by an innovative high-speed onboard opto-electronic correlation processor. SmartScan will therefore allow pushbroom scanners to be used for hyper-spectral imaging from satellites and other space platforms not primarily intended for imaging missions, such as micro- and nano-satellites with simplified attitude control, low-orbiting communications satellites, and manned space stations.
Hutchinson, Jayne; Christian, Meaghan Sarah; Evans, Charlotte Elizabeth Louise; Nykjaer, Camilla; Hancock, Neil; Cade, Janet Elizabeth
2015-08-01
Involvement of children in gardening has the potential to increase liking of fruit and vegetables (FV) and consequently, intake, but research results are mixed. School gardening led by external specialists such as the Royal Horticultural Society (RHS) could have more impact than teacher-led gardening on children's knowledge of, and attitudes towards, FV. Data from a cluster randomised controlled trial were used to compare a RHS-led school gardening intervention with a teacher-led gardening intervention amongst 7-10 year olds in 21 London schools. A short questionnaire was developed and used to identify children's knowledge and attitudes towards FV consumption before the garden intervention and 18 months afterwards. Results from multilevel regression models, both unadjusted and adjusted for baseline responses and socio-demographic factors, were reported. Attitudes to FV intake were compared between groups. Change in FV knowledge was used to predict change in FV consumption assessed using 24-hour food diaries. In comparison with the RHS-led group (n = 373), teacher-led children (n = 404) were more likely to agree they ate lots of fruit (p < 0.009) and tried new fruits (p = 0.045), but RHS-led gardening was associated with a greater increase in the total number of vegetables recognised (p = 0.031). No other differences in improvements in attitudes, or associations between change in FV recognition and intake were found. In relation to improvements in children's recognition and attitudes towards eating FV, this trial produced limited evidence that gardening activity packages led by external specialists (RHS-led) provide additional benefits over those led by teachers trained by the RHS. Indeed, the latter were potentially more effective. Copyright © 2015 Elsevier Ltd. All rights reserved.
Gold, Melanie A.; Bost, James E.; Adimora, Ada A.; Orr, Donald P.; Fortenberry, J. Dennis
2010-01-01
Purpose Little is known about how adolescent sexual behaviors develop and the influence of personal or perceived social attitudes. We sought to describe how personal, perceived peer and perceived family attitudes towards adolescent sexual activity influences adolescent females’ sexual behaviors over time. Methods Between 1999–2006, 358 English-speaking females, aged 14–17 were recruited from three urban adolescent clinics. Participants completed quarterly and annual questionnaires over 4 years. Primary outcomes were engagement in eight sexual behaviors: kissing, having breasts or genitals touched, touching partners’ genitals, and oral (giving or receiving), anal, or vaginal sex. Three attitudinal scales assessed personal importance of abstinence, perceived peer beliefs about when to have sex and perceived family beliefs that adolescent sex is negative.. We used generalized estimating equations to identify predictors of each sexual behavior and compared whether personal, perceived peer or perceived family attitudes predicted sexual behaviors over time. Results The odds of reporting each sexual behavior increased with age but were lower among those whose personal or perceived family attitudes were less positive. Participants’ personal attitudes towards adolescent sex were the strongest predictor of engagement in all eight sexual behaviors even after controlling for perceived peer and perceived family attitudes. Conclusions Female adolescent’s personal attitudes towards abstinence appear to be the strongest predictor of engagement in a variety of sexual behaviors. Efforts to influence adolescent attitudes towards abstinence may be an important approach to reducing sexual behaviors that increase the risk for pregnancy and sexually transmitted infections. PMID:21185529
JPRS Report, Soviet Union. Aviation & Cosmonautics, No. 6, June 1988
1988-12-12
squadron party organi- zation. Party members self -critically assessed their activ- ities, held violators and indifferent individuals strictly to account...courage, self -control, and decisiveness as well. These in-flight emergencies did not catch them napping. Maj A. Smir- nov safely brought his helicopter...this mood and attitude. We therefore consider everything which would help raise the level of all our pedagogic activities. I should note that this
Flight Dynamics Analysis Branch End of Fiscal Year 2004 Report
NASA Technical Reports Server (NTRS)
DeLion, Anne (Editor); Stengle, Thomas
2005-01-01
This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 595, in support of flight projects and technology development initiatives in Fiscal Year (FY) 2004. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics including spacecraft navigation (autonomous and ground based); spacecraft trajectory design and maneuver planning; attitude analysis; attitude determination and sensor calibration; and attitude control subsystem (ACS) analysis and design. The FDAB currently provides support for missions and technology development projects involving NASA, other government agencies, academia, and private industry.
Flight Dynamics Analysis Branch End of Fiscal Year 2005 Report
NASA Technical Reports Server (NTRS)
2006-01-01
This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 595, in support of flight projects and technology development initiatives in Fiscal Year (FY) 2005. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics including spacecraft navigation (autonomous and ground based), spacecraft trajectory design and maneuver planning, attitude analysis, attitude determination and sensor calibration, and attitude control subsystem (ACS) analysis and design. The FDAB currently provides support for missions and technology development projects involving NASA, other government agencies, academia, and private industry.
Racial/Ethnic Differences in Midlife Women’s Attitudes toward Physical Activity
Im, Eun-Ok; Ko, Young; Hwang, Hyenam; Chee, Wonshik; Stuifbergen, Alexa; Walker, Lorraine; Brown, Adama
2012-01-01
Introduction Women’s racial/ethnic-specific attitudes toward physical activity have been pointed out as a plausible reason for their low participation rates in physical activity. However, very little is actually known about racial/ethnic commonalties and differences in midlife women’s attitudes toward physical activity. The purpose of this study was to explore commonalities and differences in midlife women’s attitudes toward physical activity among four major racial/ethnic groups in the United States (whites, Hispanics, African Americans, and Asians). Methods This was a secondary analysis of the qualitative data from a larger study that explored midlife women’s attitudes toward physical activity. Qualitative data from four racial/ethnic-specific online forums among 90 midlife women were used for this study. The data were analyzed using thematic analysis, and themes reflecting commonalties and differences in the women’s attitudes toward physical activity across the racial/ethnic groups were extracted. Results The themes reflecting the commonalities were: (a) “physical activity is good for health”; (b) “not as active as I could be”; (c) “physical activity was not encouraged”; (d) “inherited diseases motivated participation in physical activity”; and (e) “lack of accessibility to physical activity.” The themes reflecting the differences were: (a) “physical activity as necessity or luxury”; (b) “organized versus natural physical activity”; (c) “individual versus family-oriented physical activity”; and (d) “beauty ideal or culturally accepted physical appearance.” Discussion Developing an intervention that could change the social influences and environmental factors and that could incorporate the women’s racial/ethnic-specific attitudes would be a priority in increasing physical activity of racial/ethnic minority midlife women. PMID:23931661
Attitude output feedback control for rigid spacecraft with finite-time convergence.
Hu, Qinglei; Niu, Guanglin
2017-09-01
The main problem addressed is the quaternion-based attitude stabilization control of rigid spacecraft without angular velocity measurements in the presence of external disturbances and reaction wheel friction as well. As a stepping stone, an angular velocity observer is proposed for the attitude control of a rigid body in the absence of angular velocity measurements. The observer design ensures finite-time convergence of angular velocity state estimation errors irrespective of the control torque or the initial attitude state of the spacecraft. Then, a novel finite-time control law is employed as the controller in which the estimate of the angular velocity is used directly. It is then shown that the observer and the controlled system form a cascaded structure, which allows the application of the finite-time stability theory of cascaded systems to prove the finite-time stability of the closed-loop system. A rigorous analysis of the proposed formulation is provided and numerical simulation studies are presented to help illustrate the effectiveness of the angular-velocity observer for rigid spacecraft attitude control. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Hepler, Justin; Albarracin, Dolores
2018-01-01
Dispositional attitudes are an individual difference in the tendency to form positive versus negative attitudes. As positive (negative) attitudes promote active (inactive) responses to stimuli, we predicted that dispositional attitudes would be positively correlated with patterns of general action. In Study 1, participants reported all activities they engaged in during a 1-week period using a structured time use survey. Dispositional attitudes were positively correlated with the number of unique behaviors participants engaged in and with the total number of behaviors reported for the entire week. Study 2 replicated Study 1 using a free response time use survey. Overall, the results demonstrated that dispositional attitudes predict general action, such that the tendency to form positive (negative) attitudes predicts the tendency to engage in many (few) behaviors in daily life. This pattern occurred for both low effort and high effort behaviors. Implications for understanding activity patterns are discussed. PMID:29375723
Precision Attitude Control for the BETTII Balloon-Borne Interferometer
NASA Technical Reports Server (NTRS)
Benford, Dominic J.; Fixsen, Dale J.; Rinehart. Stephen
2012-01-01
The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer to fly on a high altitude balloon. Operating at wavelengths of 30-90 microns, BETTII will obtain spatial and spectral information on science targets at angular resolutions down to less than half an arcsecond, a capability unmatched by other far-infrared facilities. This requires attitude control at a level ofless than a tenth of an arcsecond, a great challenge for a lightweight balloon-borne system. We have designed a precision attitude determination system to provide gondola attitude knowledge at a level of 2 milliarcseconds at rates up to 100Hz, with accurate absolute attitude determination at the half arcsecond level at rates of up to 10Hz. A mUlti-stage control system involving rigid body motion and tip-tilt-piston correction provides precision pointing stability to the level required for the far-infrared instrument to perform its spatial/spectral interferometry in an open-loop control. We present key aspects of the design of the attitude determination and control and its development status.
MSFC Skylab attitude and pointing control system mission evaluation
NASA Technical Reports Server (NTRS)
Chubb, W. B.
1974-01-01
The results of detailed performance analyses of the attitude and pointing control system in-orbit hardware and software on Skylab are reported. Performance is compared with requirements, test results, and prelaunch predictions. A brief history of the altitude and pointing control system evolution leading to the launch configuration is presented. The report states that the attitude and pointing system satisfied all requirements.
The MK VI - A second generation attitude control system
NASA Astrophysics Data System (ADS)
Meredith, P. J.
1986-10-01
The MK VI, a new multipurpose attitude control system for the exoatmospheric attitude control of sounding rocket payloads, is described. The system employs reprogrammable microcomputer memory for storage of basic control logic and for specific mission event control data. The paper includes descriptions of MK VI specifications and configuration; sensor characteristics; the electronic, analog, and digital sections; the pneumatic system; ground equipment; the system operation; and software. A review of the MK VI performance for the Comet Halley flight is presented. Block diagrams are included.
NASA Technical Reports Server (NTRS)
Roithmayr, Carlos M.; Karlgaard, Christopher D.; Kumar, Renjith R.; Seywald, Hans; Bose, David M.
2003-01-01
Several laws are designed for simultaneous control of the orientation of an Earth-pointing spacecraft, the energy stored by counter-rotating flywheels, and the angular momentum of the flywheels and control moment gyroscopes used together as an integrated set of actuators for attitude control. General, nonlinear equations of motion are presented in vector-dyadic form, and used to obtain approximate expressions which are then linearized in preparation for design of control laws that include feedback of flywheel kinetic energy error as a means of compensating for damping exerted by rotor bearings. Two flywheel steering laws are developed such that torque commanded by an attitude control law is achieved while energy is stored or discharged at the required rate. Using the International Space Station as an example, numerical simulations are performed to demonstrate control about a torque equilibrium attitude, and illustrate the benefits of kinetic energy error feedback. Control laws for attitude hold are also developed, and used to show the amount of propellant that can be saved when flywheels assist the CMGs. Nonlinear control laws for large-angle slew maneuvers perform well, but excessive momentum is required to reorient a vehicle like the International Space Station.
Hains, Carrie-Anne Marie; Hulbert-Williams, Nicholas J
2013-11-01
Public and healthcare professionals differ in their attitudes towards euthanasia and physician-assisted suicide (PAS), the legal status of which is currently in the spotlight in the UK. In addition to medical training and experience, religiosity, locus of control and patient characteristics (eg, patient age, pain levels, number of euthanasia requests) are known influencing factors. Previous research tends toward basic designs reporting on attitudes in the context of just one or two potentially influencing factors; we aimed to test the comparative importance of a larger range of variables in a sample of nursing trainees and non-nursing controls. One hundred and fifty-one undergraduate students (early-stage nursing training, late-stage nursing training and non-nursing controls) were approached on a UK university campus and asked to complete a self-report questionnaire. Participants were of mixed gender and were on average 25.5 years old. No significant differences in attitude were found between nursing and non-nursing students. There was a significant positive correlation between higher religiosity and positive attitude toward euthanasia (r=0.19, p<0.05) and a significant negative relationship between internal locus of control and positive attitude toward PAS (r=-0.263, p<0.01). Multivariate analyses revealed differing predictor models for attitudes towards euthanasia and PAS, and confirm the importance of individual differences in determining these attitudes. The unexpected direction of association between religiosity and attitudes may reflect a broader cultural shift in attitudes since earlier research in this area. Furthermore, these findings suggest it possible that experience, more than training itself, may be a bigger influence on attitudinal differences in healthcare professionals.
Sexual knowledge, attitudes and activity of older people in Taipei, Taiwan.
Wang, Tze-Fang; Lu, Chwen-Hwa; Chen, I-Ju; Yu, Shu
2008-02-01
We examined sexual activity and predictive factors among older people in Taipei, Taiwan. We aimed to characterize the older population engaged in sexual activity and determine influencing factors, exploring aspects of sexuality that may influence elders' health and quality of life (QOL). Studies of sexual attitudes and behaviour have found that sexual difficulties are common among mature adults worldwide, influenced in men and women by physical health, ageing, psychosocial and cultural factors. We conducted a community-based retrospective study involving a random sample of 412 men and 204 women over age 65. A questionnaire on demographics and social situations was administered, along with a Sexuality Knowledge and Attitudes Scale; 34 questions evaluated sexual knowledge and 18 evaluated sexual attitudes. Two-hundred and twenty participants were sexually active (35.7%), 185 mainly with spouses (84.1%); frequency was 21.4 (SD 16.9) times per year (range: 1-120). Multiple logistic regressions identified five significant predictors of sexual activity: gender, age, being with spouse, sexual knowledge and sexual attitudes. Sexual activity was significantly associated with higher education levels, lower stress and more self-reported daily activities. Our results agreed with Western studies linking sexual activity with better health and higher QOL in older adults. Older peoples' stress and daily activity levels are recognized quality-of-life measures; lower stress and more daily activities among sexually active older people suggests a connection between sexual activity and higher QOL. Increasing knowledge and improving attitudes about sexuality may help older people build healthier relationships and enhance health and QOL. Relevance to clinical practice. If healthcare professionals possess greater understanding of older peoples' sexuality, healthcare systems may find ways to increase sexual knowledge and foster healthier attitudes and relationships to improve older peoples' overall health and QOL.
Chinman, Matthew; Ebener, Patricia; Burkhart, Q; Osilla, Karen Chan; Imm, Pamela; Paddock, Susan M.; Wright, Patricia Ann
2017-01-01
Underage drinking is a significant problem facing US communities. Several environmental alcohol prevention (EAP) strategies (laws, regulations, responsible beverage service training and practices) successfully address underage drinking. Communities, however, face challenges carrying out these EAP strategies effectively. This small-scale, three-year, randomized controlled trial assessed whether providing prevention coalitions with Getting To Outcomes-Underage Drinking (GTO-UD), a tool kit and implementation support intervention, helped improve implementation of two common EAP strategies, responsible beverage service training (RBS) and Compliance Checks. Three coalitions in South Carolina and their RBS and Compliance Check programs received the 16 month GTO-UD intervention, including the GTO-UD manual, training, and onsite technical assistance, while another three in South Carolina maintained routine operations. The measures, collected at baseline and after the intervention, were a structured interview assessing how well coalitions carried out their work and a survey of merchant attitudes and practices in the six counties served by the participating coalitions. Over time, the quality of some RBS and Compliance Check activities improved more in GTO-UD coalitions than in the control sites. No changes in merchant practices or attitudes significantly differed between the GTO-UD and control groups, although merchants in the GTO-UD counties did significantly improve on refusing sales to minors while control merchants did not. PMID:23564504
Wammes, Birgitte; Breedveld, Boudewijn; Kremers, Stef; Brug, Johannes
2006-08-01
To help people prevent weight gain, the Netherlands Nutrition Centre initiated the 'balance intervention', which promotes moderation of food intake and/or increased physical activity in response to occasions of overeating. The aim of this study was to determine whether intervention materials were appreciated, encouraged information seeking and increased motivation and caloric compensatory behaviours. A three-group randomized trial with pre-intervention measures (n = 963, response 86%) and post-intervention measures (n = 857) using electronic questionnaires was conducted among participants aged 25-40 years, recruited from an Internet research panel. The first group received a printed brochure and electronic newsletters (print group), the second group was exposed to radio advertisements (radio group) and the third group was the control group. Multiple regression analyses were used to investigate the impact of the materials on self-reported prevalence of overeating, attitudes, perceived behavioural control, intentions and compensatory behaviours. At follow-up, we found significantly more positive attitudes, intentions and dietary action in the print and radio groups. However, participants who received the radio advertisement had a significantly lower perceived behavioural control. No effects were found on the prevalence of overeating. The results indicate that the intervention materials have potential for increasing people's attitudes, motivation and self-reported behaviour actions, with a possible negative side-effect on perceived behavioural control.
ERIC Educational Resources Information Center
Greensley, Roy J.; Gronbech, C. Eric
For this study, the physical performance levels of 73 children in grades 4-6 were assessed, and each individual was administered an adaptation of Kenyon's Attitude Toward Physical Activity (ATPA) survey. This instrument measured selected attitudes related to physical activities: social, health and fitness, risk, aesthetic, catharsis, ascetic,…
ERIC Educational Resources Information Center
Burney, Laurie; Zascavage, Victoria; Matherly, Michele
2017-01-01
Literature consistently documents a positive, direct effect of students' attitudes on learning (Lizzio, Wilson, & Simons, 2002). Hence, accounting studies describing active learning activities often report student attitudes as evidence of efficacy (e.g., Matherly & Burney, 2013), but rely on single-item instead of multi-item scales. This…
Alternative Attitude Commanding and Control for Precise Spacecraft Landing
NASA Technical Reports Server (NTRS)
Singh, Gurkirpal
2004-01-01
A report proposes an alternative method of control for precision landing on a remote planet. In the traditional method, the attitude of a spacecraft is required to track a commanded translational acceleration vector, which is generated at each time step by solving a two-point boundary value problem. No requirement of continuity is imposed on the acceleration. The translational acceleration does not necessarily vary smoothly. Tracking of a non-smooth acceleration causes the vehicle attitude to exhibit undesirable transients and poor pointing stability behavior. In the alternative method, the two-point boundary value problem is not solved at each time step. A smooth reference position profile is computed. The profile is recomputed only when the control errors get sufficiently large. The nominal attitude is still required to track the smooth reference acceleration command. A steering logic is proposed that controls the position and velocity errors about the reference profile by perturbing the attitude slightly about the nominal attitude. The overall pointing behavior is therefore smooth, greatly reducing the degree of pointing instability.
Beyond bipolar conceptualizations and measures: the case of attitudes and evaluative space.
Cacioppo, J T; Gardner, W L; Berntson, G G
1997-01-01
All organisms must be capable of differentiating hostile from hospitable stimuli to survive. Typically, this evaluative discrimination is conceptualized as being bipolar (hostile-hospitable). This conceptualization is certainly evident in the area of attitudes, where the ubiquitous bipolar attitude measure, by gauging the net affective predisposition toward a stimulus, treats positive and negative evaluative processes as equivalent, reciprocally activated, and interchangeable. Contrary to conceptualizations of this evaluative process as bipolar, recent evidence suggests that distinguishable motivational systems underlie assessments of the positive and negative significance of a stimulus. Thus, a stimulus may vary in terms of the strength of positive evaluative activation and the strength of negative evaluative activation it evokes. Low activation of positive and negative evaluative processes by a stimulus reflects attitude neutrality or indifference, whereas high activation of positive and negative evaluative processes reflects attitude ambivalence. As such, attitudes can be represented more completely within a bivariate space than along a bipolar continuum. Evidence is reviewed showing that the positive and negative evaluative processes underlying many attitudes are distinguishable (stochastically and functionally independent), are characterized by distinct activation functions (positivity offset and negativity bias principles), are related differentially to attitude ambivalence (corollary of ambivalence asymmetries), have distinguishable antecedents (heteroscedacity principle), and tend to gravitate from a bivariate toward a bipolar structure when the underlying beliefs are the target of deliberation or a guide for behavior (principle of motivational certainty). The implications for society phenomena such as political elections and democratic structures are discussed.
NASA Astrophysics Data System (ADS)
Kojima, Hirohisa; Hiraiwa, Kana; Yoshimura, Yasuhiro
2018-02-01
This paper presents the results of line-of-sight (LOS) attitude control using control moment gyros under a micro-gravity environment generated by parabolic flight. The W-Z parameters are used to describe the spacecraft attitude. In order to stabilize the current LOS to the target LOS, backstepping-based feedback control is considered using the W-Z parameters. Numerical simulations and experiments under a micro-gravity environment are carried out, and their results are compared in order to validate the proposed control methods.
Anderson, Peter; Kaner, Eileen; Keurhorst, Myrna; Bendtsen, Preben; van Steenkiste, Ben; Reynolds, Jillian; Segura, Lidia; Wojnar, Marcin; Kłoda, Karolina; Parkinson, Kathryn; Drummond, Colin; Okulicz-Kozaryn, Katarzyna; Mierzecki, Artur; Laurant, Miranda; Newbury-Birch, Dorothy; Gual, Antoni
2017-01-01
In this paper, we test path models that study the interrelations between primary health care provider attitudes towards working with drinkers, their screening and brief advice activity, and their receipt of training and support and financial reimbursement. Study participants were 756 primary health care providers from 120 primary health care units (PHCUs) in different locations throughout Catalonia, England, The Netherlands, Poland, and Sweden. Our interventions were training and support and financial reimbursement to providers. Our design was a randomized factorial trial with baseline measurement period, 12-week implementation period, and 9-month follow-up measurement period. Our outcome measures were: attitudes of individual providers in working with drinkers as measured by the Short Alcohol and Alcohol Problems Perception Questionnaire; and the proportion of consulting adult patients (age 18+ years) who screened positive and were given advice to reduce their alcohol consumption (intervention activity). We found that more positive attitudes were associated with higher intervention activity, and higher intervention activity was then associated with more positive attitudes. Training and support was associated with both positive changes in attitudes and higher intervention activity. Financial reimbursement was associated with more positive attitudes through its impact on higher intervention activity. We conclude that improving primary health care providers’ screening and brief advice activity for heavy drinking requires a combination of training and support and on-the-job experience of actually delivering screening and brief advice activity. PMID:28134783
Anderson, Peter; Kaner, Eileen; Keurhorst, Myrna; Bendtsen, Preben; Steenkiste, Ben van; Reynolds, Jillian; Segura, Lidia; Wojnar, Marcin; Kłoda, Karolina; Parkinson, Kathryn; Drummond, Colin; Okulicz-Kozaryn, Katarzyna; Mierzecki, Artur; Laurant, Miranda; Newbury-Birch, Dorothy; Gual, Antoni
2017-01-26
In this paper, we test path models that study the interrelations between primary health care provider attitudes towards working with drinkers, their screening and brief advice activity, and their receipt of training and support and financial reimbursement. Study participants were 756 primary health care providers from 120 primary health care units (PHCUs) in different locations throughout Catalonia, England, The Netherlands, Poland, and Sweden. Our interventions were training and support and financial reimbursement to providers. Our design was a randomized factorial trial with baseline measurement period, 12-week implementation period, and 9-month follow-up measurement period. Our outcome measures were: attitudes of individual providers in working with drinkers as measured by the Short Alcohol and Alcohol Problems Perception Questionnaire; and the proportion of consulting adult patients (age 18+ years) who screened positive and were given advice to reduce their alcohol consumption (intervention activity). We found that more positive attitudes were associated with higher intervention activity, and higher intervention activity was then associated with more positive attitudes. Training and support was associated with both positive changes in attitudes and higher intervention activity. Financial reimbursement was associated with more positive attitudes through its impact on higher intervention activity. We conclude that improving primary health care providers' screening and brief advice activity for heavy drinking requires a combination of training and support and on-the-job experience of actually delivering screening and brief advice activity.
Wong, Risa Liang; Fahs, Deborah Bain; Talwalkar, Jaideep S; Colson, Eve R; Desai, Mayur M; Kayingo, Gerald; Balanda, Matthew; Luczak, Anthony G; Rosenthal, Marjorie S
2016-01-01
Efforts to improve interprofessional education (IPE) are informed by attitudes of health professional students, yet there are limited US data on student characteristics and experiences associated with positive attitudes towards IPE. A cohort of US medical, nursing, and physician associate students was surveyed in their first and third years, using the Readiness for Interprofessional Learning Scale and Interdisciplinary Education Perception Scale. Information was also collected on demographics and experiences during training. Health professional students differed in their attitudes towards IPE; characteristics associated with having more positive attitudes at both time points included being a nursing student, female, older, and having more previous healthcare experience. Students who participated in interprofessional extracurricular activities (particularly patient-based activities) during training reported more positive attitudes in the third year than those who did not participate in such activities. Based on these findings, schools may consider how student characteristics and participation in interprofessional extracurricular activities can affect attitudes regarding IPE. Building on the positive elements of this interprofessional extracurricular experience, schools may also want to consider service-learning models of IPE where students work together on shared goals.
NASA Astrophysics Data System (ADS)
Zoller, Uri; Maymon, Tsipora
The effectiveness of a smoking-prevention program - incorporated within a traditional science curriculum - was assessed in terms of attitude modification in such categories as health, peer pressure, and social image as related to smoking. The study indicates that most relevant attitudes, the emotionally intense in particular, are modifiable in the desired direction, although the changes are small. Some gender differences in the recorded changes suggest a difference in the dynamics of the response to smoking intervention between male and female high school students. A desired change of attitude frequency distributions (e.g., from less extreme to more extreme responses) has also been found. In addition, the tendency of the experimental students to actively act against smoking within family circles increased, although not significantly. All the above was accompanied by a decrease in the number of smokers in the experimental group and a significant increase in the number of smokers in the control group. These results suggest that it is educationally possible to modify attitudes in health education in the desired direction by means of a properly designed interdisciplinary science curricular unit implemented within ongoing traditional science teaching.
NASA Technical Reports Server (NTRS)
Gerdes, R. M.
1980-01-01
A series of simulation and flight investigations were undertaken to evaluate helicopter flying qualities and the effects of control system augmentation for nap-of-the-Earth (NOE) agility and instrument flying tasks. Handling quality factors common to both tasks were identified. Precise attitude control was determined to be a key requirement for successful accomplishment of both tasks. Factors that degraded attitude controllability were improper levels of control sensitivity and damping, and rotor system cross coupling due to helicopter angular rate and collective pitch input. Application of rate command, attitude command, and control input decouple augmentation schemes enhanced attitude control and significantly improved handling qualities for both tasks. The NOE agility and instrument flying handling quality considerations, pilot rating philosophy, and supplemental flight evaluations are also discussed.
Velocity-free attitude coordinated tracking control for spacecraft formation flying.
Hu, Qinglei; Zhang, Jian; Zhang, Youmin
2018-02-01
This article investigates the velocity-free attitude coordinated tracking control scheme for a group of spacecraft with the assumption that the angular velocities of the formation members are not available in control feedback. Initially, an angular velocity observer is constructed based on each individual's attitude quarternion. Then, the distributed attitude coordinated control law is designed by using the observed states, in which adaptive control method is adopted to handle the external disturbances. Stability of the overall closed-loop system is analyzed theoretically, which shows the system trajectory converges to a small set around origin with fast convergence rate. Numerical simulations are performed to demonstrate fast convergence and improved tracking performance of the proposed control strategy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
A system for spacecraft attitude control and energy storage
NASA Technical Reports Server (NTRS)
Shaughnessy, J. D.
1974-01-01
A conceptual design for a double-gimbal reaction-wheel energy-wheel device which has three-axis attitude control and electrical energy storage capability is given. A mathematical model for the three-axis gyroscope (TAG) was developed, and a system of multiple units is proposed for attitude control and energy storage for a class of spacecraft. Control laws were derived to provide the required attitude-control torques and energy transfer while minimizing functions of TAG gimbal angles, gimbal rates, reaction-wheel speeds, and energy-wheel speed differences. A control law is also presented for a magnetic torquer desaturation system. A computer simulation of a three-TAG system for an orbiting telescope was used to evaluate the concept. The results of the study indicate that all control and power requirements can be satisfied by using the TAG concept.
Bhugra, D; King, M
1989-01-01
A controlled analysis of the attitudes of doctors and homosexual men to male homosexuality is reported. Not surprisingly the homosexual men held the most liberal attitudes which served as a yard-stick against which the doctors' attitudes could be assessed. The implications of these data, collected before the AIDS era, are discussed in terms of the current needs of homosexual patients. PMID:2810298
Analog neural network control method proposed for use in a backup satellite control mode
DOE Office of Scientific and Technical Information (OSTI.GOV)
Frigo, J.R.; Tilden, M.W.
1998-03-01
The authors propose to use an analog neural network controller implemented in hardware, independent of the active control system, for use in a satellite backup control mode. The controller uses coarse sun sensor inputs. The field of view of the sensors activate the neural controller, creating an analog dead band with respect to the direction of the sun on each axis. This network controls the orientation of the vehicle toward the sunlight to ensure adequate power for the system. The attitude of the spacecraft is stabilized with respect to the ambient magnetic field on orbit. This paper develops a modelmore » of the controller using real-time coarse sun sensor data and a dynamic model of a prototype system based on a satellite system. The simulation results and the feasibility of this control method for use in a satellite backup control mode are discussed.« less
Thomas, Beena; Priscilla Rebecca, B; Dhanalakshmi, A; Rani, S; Deepa Lakshmi, A; Watson, Basilea; Vijayalakshmi, R; Muniyandi, M; Karikalan, N
2016-12-01
The 'End TB strategy' has highlighted the importance of inter-sectoral collaboration and community mobilization for achieving zero TB deaths by 2020. The aim of the study was to develop and test a model TB sensitization programme involving self help groups (SHGs). This experimental study was conducted in two blocks (intervention and control), in Tiruvallur district. The intervention content included short-lecture, musical story telling activity, role play, short film on TB. The impact was compared at baseline, third and sixth months in terms of SHGs' awareness, promotion of awareness, identification and referral of presumptive TB cases and provision of TB treatment. A total of 764 vs 796 SHGs were enrolled in control and intervention groups, respectively. The knowledge attitude, and practice score (lower score indicated a better attitude and practice), from baseline to 6 months was significantly reduced (29 to 24) in the intervention group. Similarly, a significant difference was observed in identification and referral of chest symptomatics in the intervention group at 3 and 6 months. During the 3 month follow-up a significantly higher proportion of SHG members were involved in TB awareness activities in the intervention (623/748 [83.3%]) vs control group (471/728 [64.7%]; p<0.001). Findings from this study highlight the feasibility of involving SHGs through a model TB sensitization program for strengthening TB prevention and control activities. © The Author 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Feedback attitude sliding mode regulation control of spacecraft using arm motion
NASA Astrophysics Data System (ADS)
Shi, Ye; Liang, Bin; Xu, Dong; Wang, Xueqian; Xu, Wenfu
2013-09-01
The problem of spacecraft attitude regulation based on the reaction of arm motion has attracted extensive attentions from both engineering and academic fields. Most of the solutions of the manipulator’s motion tracking problem just achieve asymptotical stabilization performance, so that these controllers cannot realize precise attitude regulation because of the existence of non-holonomic constraints. Thus, sliding mode control algorithms are adopted to stabilize the tracking error with zero transient process. Due to the switching effects of the variable structure controller, once the tracking error reaches the designed hyper-plane, it will be restricted to this plane permanently even with the existence of external disturbances. Thus, precise attitude regulation can be achieved. Furthermore, taking the non-zero initial tracking errors and chattering phenomenon into consideration, saturation functions are used to replace sign functions to smooth the control torques. The relations between the upper bounds of tracking errors and the controller parameters are derived to reveal physical characteristic of the controller. Mathematical models of free-floating space manipulator are established and simulations are conducted in the end. The results show that the spacecraft’s attitude can be regulated to the position as desired by using the proposed algorithm, the steady state error is 0.000 2 rad. In addition, the joint tracking trajectory is smooth, the joint tracking errors converges to zero quickly with a satisfactory continuous joint control input. The proposed research provides a feasible solution for spacecraft attitude regulation by using arm motion, and improves the precision of the spacecraft attitude regulation.
Integrated Power and Attitude Control for a Spacecraft with Flywheels and Control Moment Gyroscopes
NASA Technical Reports Server (NTRS)
Roithmayr, Carlos M.; Karlgaard, Christopher D.; Kumar, Renjith R.; Bose, David M.
2003-01-01
A law is designed for simultaneous control of the orientation of an Earth-pointing spacecraft, the energy stored by counter-rotating flywheels, and the angular momentum of the flywheels and control moment gyroscopes used together as all integrated set of actuators for attitude control. General. nonlinear equations of motion are presented in vector-dyadic form, and used to obtain approximate expressions which are then linearized in preparation for design of control laws that include feedback of flywheel kinetic energy error as it means of compensating for damping exerted by rotor bearings. Two flywheel 'steering laws' are developed such that torque commanded by all attitude control law is achieved while energy is stored or discharged at the required rate. Using the International Space Station as an example, numerical simulations are performed to demonstrate control about a torque equilibrium attitude and illustrate the benefits of kinetic energy error feedback.
ERIC Educational Resources Information Center
Orcutt, James D.; Inmon, Rebecca R.
This paper focuses on two issues related to changing attitudes toward the female sex role among college students. First longitudinal analyses are presented in an attempt to document the fact that sex role attitude change has occurred during the past decade of student activism. A five-item scale of attitudes toward the female role used in 1961 by…
ERIC Educational Resources Information Center
Gökyürek, Belgin
2016-01-01
This study sought to explore the leisure attitudes of the individuals participating in the dance activities, to compare them on the basis of various variables and to contribute to the understanding of the relationship between these attitudes and the life satisfaction of the individual. The research sample includes 302 individuals participating in…
Affectionless control by the same-sex parents increases dysfunctional attitudes about achievement.
Otani, Koichi; Suzuki, Akihito; Matsumoto, Yoshihiko; Sadahiro, Ryoichi; Enokido, Masanori
2014-08-01
The affectionless control parenting has been associated with depression in recipients. The aim of this study was to examine the effect of this parenting style on dysfunctional attitudes predisposing to depression. The subjects were 666 Japanese volunteers. Perceived parental rearing was evaluated by the Parental Bonding Instrument, which has the care and protection subscales. Parental rearing was classified into four types, i.e., optimal parenting (high care/low protection), affectionate constraint (high care/high protection), neglectful parenting (low care/low protection), and affectionless control (low care/high protection). Dysfunctional attitudes were evaluated by the 24-item Dysfunctional Attitude Scale, which has the achievement, dependency and self-control subscales. Males with paternal affectionless control had higher achievement scores than those with paternal optimal parenting (P=.016). Similarly, females with maternal affectionless control had higher achievement scores than those with maternal optimal parenting (P=.016). The present study suggests that affectionless control by the same-sex parents increases dysfunctional attitudes about achievement. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
Attitude tracking control of flexible spacecraft with large amplitude slosh
NASA Astrophysics Data System (ADS)
Deng, Mingle; Yue, Baozeng
2017-12-01
This paper is focused on attitude tracking control of a spacecraft that is equipped with flexible appendage and partially filled liquid propellant tank. The large amplitude liquid slosh is included by using a moving pulsating ball model that is further improved to estimate the settling location of liquid in microgravity or a zero-g environment. The flexible appendage is modelled as a three-dimensional Bernoulli-Euler beam, and the assumed modal method is employed. A hybrid controller that combines sliding mode control with an adaptive algorithm is designed for spacecraft to perform attitude tracking. The proposed controller has proved to be asymptotically stable. A nonlinear model for the overall coupled system including spacecraft attitude dynamics, liquid slosh, structural vibration and control action is established. Numerical simulation results are presented to show the dynamic behaviors of the coupled system and to verify the effectiveness of the control approach when the spacecraft undergoes the disturbance produced by large amplitude slosh and appendage vibration. Lastly, the designed adaptive algorithm is found to be effective to improve the precision of attitude tracking.
Magnetic attitude control torque generation of a gravity gradient stabilized satellite
NASA Astrophysics Data System (ADS)
Suhadis, N. M.; Salleh, M. B.; Rajendran, P.
2018-05-01
Magnetic torquer is used to generate a magnetic dipole moment onboard satellites whereby a control torque for attitude control purposes is generated when it couples with the geomagnetic field. This technique has been considered very attractive for satellites operated in Low Earth Orbit (LEO) as the strength of the geomagnetic field is relatively high below the altitude of 1000 km. This paper presents the algorithm used to generate required magnetic dipole moment by 3 magnetic torquers mounted onboard a gravity gradient stabilized satellite operated at an altitude of 540 km with nadir pointing mission. As the geomagnetic field cannot be altered and its magnitude and direction vary with respect to the orbit altitude and inclination, a comparison study of attitude control torque generation performance with various orbit inclination is performed where the structured control algorithm is simulated for 13°, 33° and 53° orbit inclinations to see how the variation of the satellite orbit affects the satellite's attitude control torque generation. Results from simulation show that the higher orbit inclination generates optimum magnetic attitude control torque for accurate nadir pointing mission.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ojedokun, Oluyinka, E-mail: yinkaoje2004@yahoo.com
Highlights: > Independently, altruism and locus of control contributed significantly toward attitude towards littering. > Altruism and locus of control jointly contributed significantly to attitude towards littering. > The results further show a significant joint influence of altruism and locus of control on REB. > The independent contributions reveal that altruism and locus of control contribute significantly to REB. > Attitude towards littering mediates the relationship between locus of control and REB. - Abstract: The study tested whether attitude towards littering mediates the relationship between personality attributes (altruism and locus of control) and responsible environmental behavior (REB) among some residentsmore » of Ibadan metropolis, Nigeria. Using multistage sampling technique, measures of each construct were administered to 1360 participants. Results reveal significant independent and joint influence of personality attributes on attitude towards littering and responsible environmental behavior, respectively. Attitude towards littering also mediates the relationship between personality characteristics and REB. These findings imply that individuals who possess certain desirable personality characteristics and who have unfavorable attitude towards littering have more tendencies to engage in pro-environmental behavior. Therefore, stakeholders who have waste management as their priority should incorporate this information when guidelines for public education and litter prevention programs are being developed. It is suggested that psychologists should be involved in designing of litter prevention strategies. This will ensure the inclusion of behavioral issues in such strategies. An integrated approach to litter prevention that combines empowerment, cognitive, social, and technical solutions is recommended as the most effective tool of tackling the litter problem among residents of Ibadan metropolis.« less
Multiple Model Adaptive Attitude Control of LEO Satellite with Angular Velocity Constraints
NASA Astrophysics Data System (ADS)
Shahrooei, Abolfazl; Kazemi, Mohammad Hosein
2018-04-01
In this paper, the multiple model adaptive control is utilized to improve the transient response of attitude control system for a rigid spacecraft. An adaptive output feedback control law is proposed for attitude control under angular velocity constraints and its almost global asymptotic stability is proved. The multiple model adaptive control approach is employed to counteract large uncertainty in parameter space of the inertia matrix. The nonlinear dynamics of a low earth orbit satellite is simulated and the proposed control algorithm is implemented. The reported results show the effectiveness of the suggested scheme.
Space station systems technology study (add-on task). Volume 1: Executive summary
NASA Technical Reports Server (NTRS)
1985-01-01
System concepts were characterized in order to define cost versus benefits for autonomous functional control and for controls and displays for OMV, OTV, and spacecraft servicing and operation. The attitude control topic focused on characterizing the Space Station attitude control problem through simulation of control system responses to structural disturbances. The first two topics, mentioned above, focused on specific technology items that require advancement in order to support an early 1990s initial launch of a Space Station, while the attitude control study was an exploration of the capability of conventional controller techniques.
Study of tethered satellite active attitude control
NASA Technical Reports Server (NTRS)
Colombo, G.
1982-01-01
Existing software was adapted for the study of tethered subsatellite rotational dynamics, an analytic solution for a stable configuration of a tethered subsatellite was developed, the analytic and numerical integrator (computer) solutions for this "test case' was compared in a two mass tether model program (DUMBEL), the existing multiple mass tether model (SKYHOOK) was modified to include subsatellite rotational dynamics, the analytic "test case,' was verified, and the use of the SKYHOOK rotational dynamics capability with a computer run showing the effect of a single off axis thruster on the behavior of the subsatellite was demonstrated. Subroutines for specific attitude control systems are developed and applied to the study of the behavior of the tethered subsatellite under realistic on orbit conditions. The effect of all tether "inputs,' including pendular oscillations, air drag, and electrodynamic interactions, on the dynamic behavior of the tether are included.
White, Katherine M; Thomas, Ian; Johnston, Kim L; Hyde, Melissa K
2008-08-01
Using a prospective study of 77 1st-year psychology students' voluntary attendance at peer-assisted study sessions for statistics, the authors tested the addition of role identity to the theory of planned behavior. The authors used a revised set of role-identity items to capture the personal and social aspects of role identity within a specific behavioral context. At the commencement of the semester, the authors assessed the students' attitudes, subjective norm, perceived behavioral control, role identity, and intention. The authors examined the students' class attendance records 3 months later. Attitudes and perceived behavioral control predicted intention, with intention as the sole predictor of attendance. Role identity also predicted intention, reflecting the importance of the student role identity in influencing decision making related to supplementary academic activities.
A Flight Control Approach for Small Reentry Vehicles
NASA Technical Reports Server (NTRS)
Bevacqoa, Tim; Adams, Tony; Zhu. J. Jim; Rao, P. Prabhakara
2004-01-01
Flight control of small crew return vehicles during atmospheric reentry will be an important technology in any human space flight mission undertaken in the future. The control system presented in this paper is applicable to small crew return vehicles in which reaction control system (RCS) thrusters are the only actuators available for attitude control. The control system consists of two modules: (i) the attitude controller using the trajectory linearization control (TLC) technique, and (ii) the reaction control system (RCS) control allocation module using a dynamic table-lookup technique. This paper describes the design and implementation of the TLC attitude control and the dynamic table-lookup RCS control allocation for nonimal flight along with design verification test results.
NASA Astrophysics Data System (ADS)
Dawkins, Linda Mulderig
Science and technology are an integral part of everyday life. Therefore it is necessary that the general population have some understanding and appreciation for science. Participating in activities that are science-related is one way a person could enhance their understanding and appreciation for science. According to the Theory of Planned Behavior (TPB), the attitude and self-efficacy beliefs a person holds regarding an object or activity will influence behavioral intentions (Ajzen, 1991). Therefore, if science educators can have a positive influence on their students' attitude and sense of efficacy toward science, perhaps the result will be a populace who willingly participates in science-related activities, ultimately gaining a better understanding and appreciation for science. The present study examined the relationships between the classroom environment students experienced during a ten week period of introductory chemistry and their attitudes toward chemistry (and general science), chemistry self-efficacy, and intentions to participate in chemistry-related activities in the future. The participants of this study (N = 189) were Midwestern community college students enrolled in an introductory chemistry course. The efficacy scale of the Chemistry Attitude and Experiences Questionnaire (CAEQ) developed by Dalgety, Coll, and Jones (2003) was used to measure student chemistry self-efficacy. The attitude scale used in this study consisted of the attitude toward chemistry items of CAEQ and five additional items pertaining to general science attitude. The classroom environment scale was defined by two measures: (1) instructional pedagogies and (2) teacher immediacy behaviors. The items within the instructional pedagogies and teacher immediacy measures were based on previous research that focused on identifying teaching techniques and teacher attributes that were conducive to promoting an engaging, supportive classroom environment that would promote better attitude toward science and stronger science self-efficacy beliefs. Exploratory factor analysis of the attitude items revealed that students did not differentiate between general science attitude and chemistry attitude. Therefore, all twenty-six attitude items were combined into one attitude measure. Additionally, factor analysis revealed that the items designed to measure the separate dimensions of instructional pedagogies and teacher immediacy behavior both loaded highly on the same factor, resulting in the combing of these two sets of items into one measure of classroom environment. Structural equations modeling (SEM) analyses of the relationships between student perceptions of the classroom environment and their attitude, efficacy and intentions to participate in chemistry-related activities revealed that a positive classroom environment was associated with positive changes in both attitude toward chemistry/science and chemistry self-efficacy, as hypothesized. These analyses also supported the hypothesis that a positive change in chemistry self-efficacy beliefs mediated student intentions to participate in chemistry-related activities. However, the findings did not support the hypothesis that positive changes in attitude toward chemistry/science would mediate participation in chemistry-related activities.
Mariner Mars 1971 attitude control subsystem flight performance
NASA Technical Reports Server (NTRS)
Schumacher, L.
1973-01-01
The flight performance of the Mariner 71 attitude control subsystem is discussed. Each phase of the mission is delineated and the attitude control subsystem is evaluated within the observed operational environment. Performance anomalies are introduced and discussed within the context of general performance. Problems such as the sun sensor interface incompatibility, gas valve leaks, and scan platform dynamic coupling effects are given analytical considerations.
2000-10-23
STS-98 Mission Specialist Thomas Jones practices handling a piece of equipment on the U.S. Lab, Destiny, while wearing the gloves he will wear in space. Jones and other crew members are taking part in Crew Equipment Interface Test activities to become familiar with equipment they will be handling during the mission. With launch scheduled for Jan. 18, 2001, the STS-98 mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- STS-98 Mission Specialist Marsha Ivins takes a topsy-turvy look at the EVA hatch in the Orbiter Docking System, which is already installed in the payload bay of orbiter Atlantis. She and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-11-18
KENNEDY SPACE CENTER, FLA. -- STS-98 Mission Specialist Marsha Ivins takes a topsy-turvy look at the EVA hatch in the Orbiter Docking System, which is already installed in the payload bay of orbiter Atlantis. She and the rest of the crew are at KSC for Crew Equipment Interface Test activities. Launch on mission STS-98 is scheduled for Jan. 18, 2001. It will be transporting the U.S. Lab, Destiny, to the International Space Station with five system racks already installed inside of the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
Offu, Ogochukwu; Anetoh, Maureen; Okonta, Matthew; Ekwunife, Obinna
2015-01-01
The Nigerian health sector battles with control of infectious diseases and emerging non-communicable diseases. Number of healthcare personnel involved in public health programs need to be boosted to contain the health challenges of the country. Therefore, it is important to assess whether community pharmacists in Nigeria could be engaged in the promotion and delivery of various public health interventions. This study aimed to assess level of knowledge, attitude and practice of public health by community pharmacists. The cross sectional survey was carried out in Enugu metropolis. Questionnaire items were developed from expert literature. Percentage satisfactory knowledge and practice were obtained by determining the percentage of community pharmacists that were able to list more than 2 activities or that stated the correct answer. Attitude score represents the average score on the 5 point Likert scale for each item. Chi square and Fisher's exact test were used to test for statistically significant difference in knowledge, attitude and practice of public health between different groups of community pharmacists. Forty pharmacists participated in the survey. About one third of the participants had satisfactory knowledge of public health. With the exception of one item in attitude assessment, average item score ranged from 'agreed' to 'strongly agreed'. Study participants scored below satisfactory on practice of public health. Knowledge, attitude and practice of public health were not influenced by years of practice, qualification and prior public health experience. Reported barriers to the practice of public health include inadequate funds, lack of time, lack of space, cooperation of clients, inadequate staff, government regulation, insufficient knowledge, and remuneration. Level of knowledge and practice of public health by community pharmacists were not satisfactory although they had a positive attitude towards practice of public health. The findings highlight the importance of educational interventions targeted towards practicing community pharmacists to improve their knowledge level on public health issues. Providing incentives for public health services rendered could increase community pharmacists' engagement in public health activities.
Barrier Island Activity to Illustrate Hands-On Science
NASA Astrophysics Data System (ADS)
Griffin, Suzanne H.
The department of Physics of the University of Glasgow was concerned about losing students after the end of the level 1 Physics course. The current research project started as an attempt to find out the reasons for this, but moved to investigate attitudes towards Physics at several stages during secondary school and attitudes towards science with primary pupils. Analyses of factors, which influence students' intentions towards studying Physics, were performed against the background of the Theory of Planned Behaviour, which interprets people's behaviour by considering three factors: attitude towards behaviour (advantages or disadvantages of being involved in the behaviour, e.g. studying Physics for Honours); subjective norm (approval or disapproval of important people towards engaging in the behaviour, e.g. parents, teacher, general norms of the society); perceived behavioural control (skills, knowledge, cooperation of others, abilities, efforts required to perform the behaviour). Analysis of these factors revealed some reasons for students' withdrawal from Physics after level 1 and pointed to factors which may facilitate students' persistence in the subject. A general analysis of level 1 and level 2 students' attitudes towards different aspects of the university Physics course revealed that the level 1 students' attitudes towards their university course of lectures and course of laboratories tended to be negatively polarised. Recommendations were suggested on the basis of the gathered evidence about how to make students' experience in university Physics more satisfactory for them. The data obtained from the separate analyses of females' and males' attitudes towards university Physics course have showed that attitudes of females and males were similar. The only significant difference between level 1 females and males was found to be the perceived behavioural control factor (students' attitudes towards course difficulty, attitudes towards work load in the course), which was significantly lower for females than for males. Special attention in this work was given to the problem of university Physics laboratory practice. Possibilities to improve students' attitudes towards laboratory work were discussed. This could be done through introduction of pre-lab (aimed to consolidate students' grasp of the necessary background for performing the experiment) and post-lab (aimed to provide students with opportunity to apply the theory they have learned and skills they have obtained from doing laboratory work to solve everyday problems). Examples of pre- and post-labs that were designed for the first term of the level 1 university Physics laboratory practice are given in the Appendix T. The project was extended from the university to the school area where cross-age analyses (measurements at one time with pupils of different age) of pupils' attitudes towards Science/Physics lessons were performed. Pupils from upper Primary P6/P7 up to Higher S5/S6 were involved in the research. These analyses have shown that patterns of Scottish pupils' attitudes towards Science/Physics lessons are not linear with age: attitudes of pupils who were self-selected towards the subject were not always more positive than attitudes of lower level pupils: primary school pupils' attitudes towards science lessons were significantly more positive than attitudes of secondary S2 pupils; pupils doing Standard Grade Physics course were similar in their evaluations of Physics lessons at both S3 and S4 levels; at Higher Grade Physics pupils' attitudes towards science lessons were significantly less positive than attitudes of Standard Grade Physics pupils. Pupils' attitudes towards Science/Physics lessons can be considered as a good indicator of pupils' reactions towards existing syllabuses in Science and Physics. Special attention in this study was devoted to the so-called "problem of girls in Physics". Separate analyses of boys' and girls' interests towards Physics topics revealed that although boys and girls are equally interested in certain areas of the subject, there are areas in Physics where boys and girls interests are significantly different. No differences were found in intensity of boys' and girls' interests towards suggested Physics topics at primary P6/P7 level, S3 and S5/S6 levels. At S2 and S4 levels a significant decline of girls' interests relative to boys interests was observed. S2 and S4 stages are decision making ones when pupils have the opportunity to select courses for the future. It was also revealed that the ratio of boys to girls in Physics once established at S2 level remains unchanged through the years of Standard Grade and Higher Grade Physics courses. This may indicate that if the number of girls in Physics is an issue for concern then attention should be paid to the primary and, especially early secondary years to attract girls to Physics. School Physics courses in Scotland revealed a high retention rate of girls in Physics. Analyses of preferred activities revealed that practical work is the most enjoyable activity in Science/Physics lessons for both girls and boys at every stage of schooling and studying the theory was found to be the least enjoyable activity at school for both genders at every age. The picture was almost the reverse with university Physics students.
Flight Dynamics Analysis Branch
NASA Technical Reports Server (NTRS)
Stengle, Tom; Flores-Amaya, Felipe
2000-01-01
This report summarizes the major activities and accomplishments carried out by the Flight Dynamics Analysis Branch (FDAB), Code 572, in support of flight projects and technology development initiatives in fiscal year 2000. The report is intended to serve as a summary of the type of support carried out by the FDAB, as well as a concise reference of key accomplishments and mission experience derived from the various mission support roles. The primary focus of the FDAB is to provide expertise in the disciplines of flight dynamics, spacecraft trajectory, attitude analysis, and attitude determination and control. The FDAB currently provides support for missions and technology development projects involving NASA, government, university, and private industry.
Output Feedback Slewing Control of Flewible Spacecraft by
NASA Astrophysics Data System (ADS)
Kim, Daesik; Kim, Chun-Hwey; Bang, Hyochoong
1997-12-01
Slewing maneuver and vibration suppression control of flexible spacecraft model by Lyapunov stability theory are considered. The specific model considered in this paper consists of a rigid hub with an elastic appendage attached to the central hub and tip mass. Attitude control to point and stabilize single axis using reaction wheel type device is tested. To control all flexible modes is so critical to designing an active control law. We therefore considered an direct output feeback control design by using Lyapunov stability theory. It is shown that the ouput feedback control law design with proposed configuration gives satisfactory result in slewing performance and vibration suppression control.
Katz, Jennifer; Schneider, Monica E
2013-11-01
This study examined bidirectional relationships among emerging adults' involvement in casual hook up sex and attitudes about sex and love relationships. At the start and end of their first year in college, undergraduates (N = 163) responded to measures of sexual behavior, sexual attitudes, and attitudes about love relationships. In cross-sectional analyses, attitudes about sex and love both were associated with involvement in casual hook up sex. In prospective analyses, initial attitudes about sexual instrumentality uniquely predicted involvement in later hook up sex, even after controlling for past hook up sex. Furthermore, involvement in hook up sex during the first year of college predicted greater sexual permissiveness and comfort with casual genital contact, even after controlling for initial sexual attitudes and hook up behaviors. None of the associations between attitudes and behavior were qualified by gender. Experiences of causal hook up sex appear to have implications primarily for emerging adults' attitudes about sexual interactions rather than their attitudes about love relationships.
Parling, Thomas; Cernvall, Martin; Stewart, Ian; Barnes-Holmes, Dermot; Ghaderi, Ata
2012-01-01
Implicit pro-thin/anti-fat attitudes were investigated among a mixed group of patients with full and sub-threshold Anorexia Nervosa (n = 17), and a matched-age control group (n = 17). The Implicit Relational Assessment Procedure (IRAP) was employed to measure implicit pro-thin and anti-fat attitudes towards Self and Others in addition to "striving for thinness" and "avoidance of fatness." The clinical group showed an implicit pro-fat attitude towards Others and stronger anti-fat attitudes towards Self and avoidance of fatness compared with controls. The findings are discussed in relation to the over-evaluation of weight and shape in the clinical group.
Make a Move Intervention to Reduce Childhood Obesity
ERIC Educational Resources Information Center
Nerud, Kimberly; Samra, Haifa
2017-01-01
Guided by the social cognitive theory, this randomized controlled trial tested the "Make a Move," a provider-led intervention for Head Start parents aimed to produce changes in the outcomes of knowledge, attitude, and behavior of physical activity and healthy eating. Participants were parents of children ages 3-5 years enrolled in a Head…
Recognition of Values-Based Constructs in a Summer Physical Activity Program.
ERIC Educational Resources Information Center
Watson, Doris L.; Newton, Maria; Kim, Mi-Sook
2003-01-01
Examined the extent to which participants in a summer sports camp embraced values-based constructs, noting the relationship between perceptions of values-based constructs and affect and attitude. Data on ethnically diverse 10-13-year-olds indicated that care for others/goal setting, self-responsibility, and self-control/respect positively related…
Nudging Resisters Toward Change: Self-Persuasion Interventions for Reducing Attitude Certainty.
Greenberg, Spencer; Brand, Danielle; Pluta, Aislinn; Moore, Douglas; DeConti, Kirsten
2018-05-01
To identify effective self-persuasion protocols that could easily be adapted to face-to-face clinical sessions or health-related computer applications as a first step in breaking patient resistance. Two self-persuasion interventions were tested against 2 controls in a between-subject randomized control experiment. GuidedTrack-a web-based platform for social science experiments. Six hundred seventeen adult participants recruited via Mechanical Turk. The experimental interventions prompted participants for self-referenced pro- and counterattitudinal arguments to elicit attitude-related thought (ART) and subsequent doubt about the attitude. The hypothesis was that the self-persuasion interventions would elicit larger and more frequent attitude certainty decreases than the controls. In the experimental groups, we also predicted a correlation between the amount of ART and attitude certainty decreases. Changes in attitude certainty were measured by participants' pre- and post-ratio scale ratings; ART was measured by the number of words participants used to respond to the interventions. Analysis of variance (ANOVA), χ 2 , and correlation. A goodness-of-fit χ 2 showed that the number of participants who decreased their attitude certainty was not equally distributed between the combined experimental groups (n = 104) and the combined control groups (n = 39), χ 2 (1, n = 143) = 28.64, P < .001. Within each intervention, goodness-of-fit χ 2 with a Bonferroni correction ( P = .01 or .05/4) indicated there were significantly more "decreasers" than "increasers" in intervention 1, χ 2 (1, n = 86) = 6.16, P = .01, but not intervention 2, χ 2 (1, n = 84) = 2.02, P = .16, the nonsense control, χ 2 (1, n = 42) = .22, P = .64), or the distraction control, χ 2 (1, n = 34) = .02, P = .89. A 1-way ANOVA revealed a significant main effect for intervention on mean certainty change ( F 3,613 = 4.62, P = .003). Five post hoc comparisons using Tukey's honest significant difference (HSD) test indicated that the mean decrease in attitude certainty resulting from intervention 1 (M = -3.29) was significantly larger than the mean decrease in attitude certainty resulting from the nonsense control (M = -0.62, t = -2.72, P = .03), the distraction control (M = 0.11, t = 3.48, P = .003), but not intervention 2 (M = -0.87, t = -2.54, P = .06). Attitude-related thought was significantly correlated with attitude certainty change in intervention 1, r(158) = -.17, t = -4.28, P = .02, but not intervention 2, r(161) = -.002, t = -.03, P = .98. The implication for clinical practitioners and designers of health applications is that it may be worthwhile to let patients elaborate on their personal reasons for initially forming an unhealthy attitude to increase doubt about the strongly held attitude.
Gun Attitudes and Fear of Crime.
ERIC Educational Resources Information Center
Heath, Linda; Weeks, Kyle; Murphy, Marie Mackay
1997-01-01
Using three studies, examined the relationship between attitudes toward guns and fear of crime. Findings indicate a connection between fear of crime and attitudes toward guns: people higher in fear of crime favored gun control. Results also established a relationship between stereotypical beliefs about gun victims and support for gun control. (RJM)
Students' Attitudes towards Control Methods in Computer-Assisted Instruction.
ERIC Educational Resources Information Center
Hintze, Hanne; And Others
1988-01-01
Describes study designed to investigate dental students' attitudes toward computer-assisted teaching as applied in programs for oral radiology in Denmark. Programs using personal computers and slide projectors with varying degrees of learner and teacher control are described, and differences in attitudes between male and female students are…
“A Waste of Time”: Hispanic Women's Attitudes toward Physical Activity
Im, Eun-Ok; Lee, Bokim; Hwang, Hyenam; Yoo, Kyung Hee; Chee, Wonshik; Stuifbergen, Alexa; Walker, Lorraine; Brown, Adama; McPeek, Chelsea; Miro, Michelle; Chee, Eunice
2010-01-01
Despite a lack of studies on Hispanic midlife women's physical activity, the existing studies have indicated that Hispanics' ethnic-specific attitudes toward physical activity contributed to their lack of physical activity. However, little is still clearly known about Hispanic midlife women's attitudes toward physical activity. The purpose of this study was to explore Hispanic midlife women's attitudes toward physical activity using a feminist perspective. The study was a 6-month qualitative online forum among 23 Hispanic women who were recruited through Internet communities/groups. The data were collected using 17 online forum topics on attitudes toward physical activity and ethnic-specific contexts. The data were analyzed using thematic analysis. Three major themes emerged from the data analysis process: (a) “family first, no time for myself,” (b) “little exercise, but naturally healthy,” and (c) “dad died of heart attack.” Although some of the women perceived the importance of physical activity due to their family history of chronic diseases, the study participants thought that physical activity would be a waste of time in their busy daily schedules. These findings provided directions for future health care practice and research to increase physical activity among Hispanic midlife women. PMID:20981637
Banchonhattakit, Pannee; Tanasugarn, Chanuantong; Pradipasen, Mandhana; Miner, Kathleen R; Nityasuddhi, Dechavudh
2009-07-01
This research was designed to test the effectiveness of a school network for childhood obesity prevention (SNOCOP) in primary schools; a program that aimed to improve student behavior in terms of knowledge, attitude, intention towards obesity prevention, and their food consumption behavior. A quasi-experimental pretest-posttest time series study was conducted. By 2-stage stratified sampling selection 180 students from 6 schools were assigned to the intervention group and 195 students from 6 schools to the control group at Saraburi Province, Thailand in 2006- 2007. In addition, thirty-one participants being school administrators, teachers, parents, and community members from six schools formed the social network initiating the intervention. The schoolchildren in the intervention group improved their eating behavior, knowledge, attitude, intention towards obesity preventive behavior. The six schools of the intervention group changed school policies and school activities aiming to reduce the proportion of obesity among their student. No such activities could be observed in the control group. These findings suggest that the School-Social Network of Childhood Obesity Prevention program is an effective means to prevent childhood obesity.
NASA Technical Reports Server (NTRS)
Guglielmo, David; Omar, Sanny R.; Bevilacqua, Riccardo
2017-01-01
The increasing number of CubeSats being launched has raised concerns about orbital debris since most of these satellites have no means of active orbit control. Some technologies exist to increase the surface area of a CubeSat and expedite de-orbit due to aerodynamic drag in low Earth orbit, but most of these devices cannot be retracted and hence cannot be used for orbital maneuvering. This paper discusses the De-Orbit Drag Device (D3) module that is capable of de-orbiting a 12U, 15kg CubeSat from a 700 km circular orbit in under 25 years and can be deployed and retracted to modulate the aerodynamic drag force experienced by the satellite. This facilitates orbital maneuvering using aerodynamic drag and the active targeting of a de-orbit location. In addition, the geometry of this drag device provides 3-axis attitude stabilization of the host CubeSat using aerodynamic and gravity gradient torques which is useful for many missions and provides a predictable aerodynamic profile for use in orbital maneuvering algorithms.
O'Connell, Megan E; Dal Bello-Haas, Vanina; Crossley, Margaret; Morgan, Debra G
2015-01-01
Regular physical activity and exercise (PA&E) reduces cognitive aging, may delay dementia onset, and for persons with dementia, may slow progression and improve quality of life. Memory clinic patients and caregivers described their PA&E and completed the Older Persons' Attitudes Toward Physical Activity and Exercise Questionnaire (OPAPAEQ). Caregivers and patients differed in their PA&E attitudes: patients were less likely to believe in the importance of PA&E for health promotion. PA&E attitudes were explored as predictors of self-reported exercise habits. Belief in the importance of high intensity exercise for health maintenance was the only variable that significantly predicted engagement in regular PA&E. Moreover, caregivers' attitudes toward high intensity exercise predicted memory patients' participation in PA&E. These findings may aid in development of exercise interventions for people with memory problems, and suggest that modification of specific attitudes toward exercise is an important component to ensure maximum participation and engagement in PA&E.
NASA Astrophysics Data System (ADS)
Viswanathan, Sasi Prabhakaran
Design, dynamics, control and implementation of a novel spacecraft attitude control actuator called the "Adaptive Singularity-free Control Moment Gyroscope" (ASCMG) is presented in this dissertation. In order to construct a comprehensive attitude dynamics model of a spacecraft with internal actuators, the dynamics of a spacecraft with an ASCMG, is obtained in the framework of geometric mechanics using the principles of variational mechanics. The resulting dynamics is general and complete model, as it relaxes the simplifying assumptions made in prior literature on Control Moment Gyroscopes (CMGs) and it also addresses the adaptive parameters in the dynamics formulation. The simplifying assumptions include perfect axisymmetry of the rotor and gimbal structures, perfect alignment of the centers of mass of the gimbal and the rotor etc. These set of simplifying assumptions imposed on the design and dynamics of CMGs leads to adverse effects on their performance and results in high manufacturing cost. The dynamics so obtained shows the complex nonlinear coupling between the internal degrees of freedom associated with an ASCMG and the spacecraft bus's attitude motion. By default, the general ASCMG cluster can function as a Variable Speed Control Moment Gyroscope, and reduced to function in CMG mode by spinning the rotor at constant speed, and it is shown that even when operated in CMG mode, the cluster can be free from kinematic singularities. This dynamics model is then extended to include the effects of multiple ASCMGs placed in the spacecraft bus, and sufficient conditions for non-singular ASCMG cluster configurations are obtained to operate the cluster both in VSCMG and CMG modes. The general dynamics model of the ASCMG is then reduced to that of conventional VSCMGs and CMGs by imposing the standard set of simplifying assumptions used in prior literature. The adverse effects of the simplifying assumptions that lead to the complexities in conventional CMG design, and how they lead to CMG singularities, are described. General ideas on control of the angular momentum of the spacecraft using changes in the momentum variables of a finite number of ASCMGs, are provided. Control schemes for agile and precise attitude maneuvers using ASCMG cluster in the absence of external torques and when the total angular momentum of the spacecraft is zero, is presented for both constant speed and variable speed modes. A Geometric Variational Integrator (GVI) that preserves the geometry of the state space and the conserved norm of the total angular momentum is constructed for numerical simulation and microcontroller implementation of the control scheme. The GVI is obtained by discretizing the Lagrangian of the rnultibody systems, in which the rigid body attitude is globally represented on the Lie group of rigid body rotations. Hardware and software architecture of a novel spacecraft Attitude Determination and Control System (ADCS) based on commercial smartphones and a bare minimum hardware prototype of an ASCMG using low cost COTS components is also described. A lightweight, dynamics model-free Variational Attitude Estimator (VAE) suitable for smartphone implementation is employed for attitude determination and the attitude control is performed by ASCMG actuators. The VAE scheme presented here is implemented and validated onboard an Unmanned Aerial Vehicle (UAV) platform and the real time performance is analyzed. On-board sensing, data acquisition, data uplink/downlink, state estimation and real-time feedback control objectives can be performed using this novel spacecraft ADCS. The mechatronics realization of the attitude determination through variational attitude estimation scheme and control implementation using ASCMG actuators are presented here. Experimental results of the attitude estimation (filtering) scheme using smartphone sensors as an Inertial Measurement Unit (IMU) on the Hardware In the Loop (HIL) simulator testbed are given. These results, obtained in the Spacecraft Guidance, Navigation and Control Laboratory at New Mexico State University, demonstrate the performance of this estimation scheme with the noisy raw data from the smartphone sensors. Keywords: Spacecraft, momentum exchange devices, control moment gyroscope, variational mechanics, geometric mechanics, variational integrators, attitude determination, attitude control, ADCS, estimation, ASCMG, VSCMG, cubesat, mechatronics, smartphone, Android, MEMS sensor, embedded programming, microcontroller, brushless DC drives, HIL simulation.
Teaching science for public understanding: Developing decision-making abilities
NASA Astrophysics Data System (ADS)
Siegel, Marcelle A.
One of the most important challenges educators have is teaching students how to make decisions about complex issues. In this study, methods designed to enhance students' decision-making skills and attitudes were investigated. An issue-oriented science curriculum was partly replaced with activities designed by the experimenter. The first objective of the study was to examine the effects of an instructional method to increase students' use of relevant scientific evidence in their decisions. The second goal of the research was to test whether the instructional activities could promote students' beliefs that science is relevant to them, because attitudes have been shown to affect students' performance and persistence (Schommer, 1994). Third, the study was designed to determine whether the instructional activities would affect students' beliefs that their intelligence is not fixed but can grow; this question is based on Dweck and Leggett's (1988) definition of two orientations toward intelligence---entity theorists and incremental theorists (Dweck & Leggett, 1988; Dweck & Henderson, 1989). Two urban high-school classrooms participated in this study. Tenth graders examined scientific materials about current issues involving technology and society. Instructional materials on decision making were prepared for one class of students to enhance their regular issue-oriented course, Science and Sustainability. A computer program, called Convince Me (Schank, Ranney & Hoadley, 1996), provided scaffolding for making an evidence-based decision. The experimental group's activities also included pen-and-paper lessons on decision making and the effect of experience on the structure of the brain. The control class continued to engage in Science and Sustainability decision-making activities during the time the experimental class completed the treatment. The control group did not show significant improvement on decision-making tasks, and the experimental group showed marginally significant gains (p = .06) according to the Rasch analysis. A measure of students' understanding of coherent argumentation was correlated with higher decision posttest scores. Over time, both classes significantly regarded science as being more relevant to everyday life. Students' attitudes about ability showed insignificant changes.
Review of Research On Guidance for Recovery from Pitch Axis Upsets
NASA Technical Reports Server (NTRS)
Harrison, Stephanie J.
2016-01-01
A literature review was conducted to identify past efforts in providing control guidance for aircraft upset recovery including stall recovery. Because guidance is integrally linked to the intended function of aircraft attitude awareness and upset recognition, it is difficult, if not impossible, to consider these issues separately. This literature review covered the aspects of instrumentation and display symbologies for attitude awareness, aircraft upset recognition, upset and stall alerting, and control guidance. Many different forms of symbology have been investigated including, but not limited to, pitch scale depictions, attitude indicator icons, horizon symbology, attitude recovery arrows, and pitch trim indicators. Past research on different visual and alerting strategies that provide advisories, cautions, and warnings to pilots before entering an unusual attitude (UA) are also discussed. Finally, potential control guidance for recovery from upset or unusual attitudes, including approach-to-stall and stall conditions, are reviewed. Recommendations for future research are made.
ATTITUDES TOWARD SUICIDE: THE EFFECT OF SUICIDE DEATH IN THE FAMILY*
Zhang, Jie; Jia, Cun-Xian
2011-01-01
There have been few reports on the effect of suicide death on family members’ attitudes toward suicide. In order to estimate the extent to which suicide death affects attitudes toward suicide among family members of suicides, data of 264 informants from a case-control psychological autopsy study were analyzed. The results showed that there were no significant differences in attitudes toward suicide, measured by the General Social Survey’s (GSS) four questions, between informants of suicides and informants of living controls, between family members of suicides and family members of living controls, or between family members of suicides and non-family members of suicides. Our findings did not support the hypothesis that suicide death affects the attitudes toward suicide in suicides’ family members. However, some factors were found to be related to the pro-suicide attitudes measured by the four questions included in the GSS. PMID:20397616
Attitudes toward menstruation in females with schizophrenia or schizoaffective disorders in Taiwan.
Liang, H-Y; Lee, L-W; Kelsen, B A; Hsu, S-C; Liu, C-Y; Chen, C-Y
2013-12-01
The aims of this cross-sectional, case-controlled, observational study were to examine attitudes toward menstruation in female patients with schizophrenia or schizoaffective disorder and in a control group, and to explore the associations between attitudes toward menstruation and psychopathology, menstrual regularity during antipsychotic treatment, and menstrual distress symptoms. Fifty-eight patients treated with anti-psychotic medications for at least the previous 6 months were placed in irregular (irregular menstrual cycle) (n = 31) and regular (regular menstrual cycle) (n = 27) groups. Sixty-two, age-matched, healthy female participants with regular menstrual cycles were enrolled as a control group. Psychopathology was assessed by psychiatrists using the Positive and Negative Syndrome Scale (PANSS). The Menstrual Attitude Questionnaire (MAQ) was used to assess attitudes toward menstruation, and symptom checklists based on the Moos Menstruation Distress Questionnaire (MMDQ) were used to assess menstrual distress symptoms. Patients with psychotic disorders (both irregular and regular groups) had more negative attitudes toward menstruation than the control group. In the Schizophrenia group, there was no association between the severity of psychotic symptoms and their influence on attitudes toward menstruation. Moreover, regular menstrual cycles during antipsychotic treatment and fewer menstrual distress symptoms were the two main predictors for more positive attitudes toward menstruation in the patient group. This is one of the first studies to explore the relationship between psychotic symptoms and attitudes toward menstruation. The findings provide more support for the assumption that attitudes toward menstruation are derived from a woman's perception of her bodily experience rather than a psychiatric disorder.
A Micromechanical INS/GPS System for Small Satellites
NASA Technical Reports Server (NTRS)
Barbour, N.; Brand, T.; Haley, R.; Socha, M.; Stoll, J.; Ward, P.; Weinberg, M.
1995-01-01
The cost and complexity of large satellite space missions continue to escalate. To reduce costs, more attention is being directed toward small lightweight satellites where future demand is expected to grow dramatically. Specifically, micromechanical inertial systems and microstrip global positioning system (GPS) antennas incorporating flip-chip bonding, application specific integrated circuits (ASIC) and MCM technologies will be required. Traditional microsatellite pointing systems do not employ active control. Many systems allow the satellite to point coarsely using gravity gradient, then attempt to maintain the image on the focal plane with fast-steering mirrors. Draper's approach is to actively control the line of sight pointing by utilizing on-board attitude determination with micromechanical inertial sensors and reaction wheel control actuators. Draper has developed commercial and tactical-grade micromechanical inertial sensors, The small size, low weight, and low cost of these gyroscopes and accelerometers enable systems previously impractical because of size and cost. Evolving micromechanical inertial sensors can be applied to closed-loop, active control of small satellites for micro-radian precision-pointing missions. An inertial reference feedback control loop can be used to determine attitude and line of sight jitter to provide error information to the controller for correction. At low frequencies, the error signal is provided by GPS. At higher frequencies, feedback is provided by the micromechanical gyros. This blending of sensors provides wide-band sensing from dc to operational frequencies. First order simulation has shown that the performance of existing micromechanical gyros, with integrated GPS, is feasible for a pointing mission of 10 micro-radians of jitter stability and approximately 1 milli-radian absolute error, for a satellite with 1 meter antenna separation. Improved performance micromechanical sensors currently under development will be suitable for a range of micro-nano-satellite applications.
Physical activities and influencing factors among public health nurses: a cross-sectional study.
Lin, Miao-Ling; Huang, Joh-Jong; Chuang, Hung-Yi; Tsai, Hsiu-Min; Wang, Hsiu-Hung
2018-04-20
Public health nurses are responsible for promoting and managing the health of community members, and if they do not have enough physical activity or ignore their own health, not only will their own health decline but the quality of life of the public will also be affected. This study investigated the physical activity of public health nurses and analysed the effects of attitudes, subjective norms, perceived behavioural control and behavioural intention to engage in physical activity. This study adopted a cross-sectional research design, and convenience sampling was used to select the research subjects. 198 public health nurses were invited to participate, and 172 completed the questionnaire. Multiple linear regression was used to analyse the influencing factors of physical activity intention and physical activity. Attitudes towards physical activity and perceived behavioural control of physical activity affected physical activity intention. When they had higher behavioural intention, their physical activity behaviour also improved. The physical activity intention significantly influenced the number of days that they had engaged in vigorous physical activity (95% CI 0.1786 to 0.3060, p<0.0001), and significantly influenced the number of days that they walked daily for 10 min (95% CI 0.2158 to 0.4144, p<0.0001), and also significantly influenced their daily sedentary time (95% CI -0.3020 to 0.0560, p=0.0046). Encouraging public health nurses to heed their own health and motivating them to engage in physical activity warrants attention from policy-makers and government health agencies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Thermal design and simulation of an attitude-varied space camera
NASA Astrophysics Data System (ADS)
Wang, Chenjie; Yang, Wengang; Feng, Liangjie; Li, XuYang; Wang, Yinghao; Fan, Xuewu; Wen, Desheng
2015-10-01
An attitude-varied space camera changes attitude continually when it is working, its attitude changes with large angle in short time leads to the significant change of heat flux; Moreover, the complicated inner heat sources, other payloads and the satellite platform will also bring thermal coupling effects to the space camera. According to a space camera which is located on a two dimensional rotating platform, detailed thermal design is accomplished by means of thermal isolation, thermal transmission and temperature compensation, etc. Then the ultimate simulation cases of both high temperature and low temperature are chosen considering the obscuration of the satellite platform and other payloads, and also the heat flux analysis of light entrance and radiator surface of the camera. NEVEDA and SindaG are used to establish the simulation model of the camera and the analysis is carried out. The results indicate that, under both passive and active thermal control, the temperature of optical components is 20+/-1°C,both their radial and axial temperature gradient are less than 0.3°C, while the temperature of the main structural components is 20+/-2°C, and the temperature fluctuation of the focal plane assemblies is 3.0-9.5°C The simulation shows that the thermal control system can meet the need of the mission, and the thermal design is efficient and reasonable.
Hartman, Anne M; Thun, Michael J; Ballard-Barbash, Rachel
2008-09-01
State tobacco control programs provide an important laboratory for the development, implementation, and evaluation of comprehensive tobacco control interventions. Studies have shown that states and municipalities with aggressive tobacco control programs have experienced more rapid decreases in per capita cigarette sales, smoking prevalence, lung cancer, and heart disease than entities without such programs. Despite strong evidence that population-level interventions are critical in achieving large and sustained reductions in tobacco use, states do not fund tobacco control efforts at levels recommended by the Centers for Disease Control and Prevention. Research on the effectiveness and cost effectiveness of these activities is essential to inform and strengthen tobacco control at the state level. A workshop, co-organized by the American Cancer Society, the National Cancer Institute, the American Association for Cancer Research, and the Centers for Disease Control and Prevention, was held in Philadelphia in December, 2007, to discuss the topic "Linking tobacco control policies and practices to early cancer endpoints: surveillance as an agent for change." Participants represented three different disciplines. Tobacco surveillance researchers described the data currently collected on state-level tobacco control policies, protobacco countermeasures by the industry, public attitudes toward tobacco use, and measures of smoking prevalence and consumption. Cancer registry experts described the geographic coverage of high quality, population-based cancer registries. Mathematical modeling experts discussed various modeling approaches that can be used to relate upstream tobacco promotion and control activities to downstream measures such as public attitudes, changes in tobacco use, and trends in tobacco-related diseases. The most important recommendation of the Workshop was a call for national leadership to enhance the collection and integration of data from multiple sources as a resource to further study and strengthen the scientific basis for tobacco control.
Control measures to trace ≤ 15-year-old contacts of index cases of active pulmonary tuberculosis
Oliveira, Cláudia Di Lorenzo; de Melo, Angelita Cristine; de Oliveira, Lílian Ruth Silva; Froede, Emerson Lopes; Camargos, Paulo
2015-01-01
This was descriptive study carried out in a medium-sized Brazilian city. In ≤ 15-year-old contacts of index cases of active pulmonary tuberculosis, we assessed compliance with the Brazilian national guidelines for tuberculosis control. We interviewed 43 contacts and their legal guardians. Approximately 80% of the contacts were not assessed by the municipal public health care system, and only 21% underwent tuberculin skin testing. The results obtained with the Chi-square Automatic Interaction Detector method suggest that health care teams have a biased attitude toward assessing such contacts and underscore the need for training health professionals regarding tuberculosis control programs. PMID:26578137
Model predictive and reallocation problem for CubeSat fault recovery and attitude control
NASA Astrophysics Data System (ADS)
Franchi, Loris; Feruglio, Lorenzo; Mozzillo, Raffaele; Corpino, Sabrina
2018-01-01
In recent years, thanks to the increase of the know-how on machine-learning techniques and the advance of the computational capabilities of on-board processing, expensive computing algorithms, such as Model Predictive Control, have begun to spread in space applications even on small on-board processor. The paper presents an algorithm for an optimal fault recovery of a 3U CubeSat, developed in MathWorks Matlab & Simulink environment. This algorithm involves optimization techniques aiming at obtaining the optimal recovery solution, and involves a Model Predictive Control approach for the attitude control. The simulated system is a CubeSat in Low Earth Orbit: the attitude control is performed with three magnetic torquers and a single reaction wheel. The simulation neglects the errors in the attitude determination of the satellite, and focuses on the recovery approach and control method. The optimal recovery approach takes advantage of the properties of magnetic actuation, which gives the possibility of the redistribution of the control action when a fault occurs on a single magnetic torquer, even in absence of redundant actuators. In addition, the paper presents the results of the implementation of Model Predictive approach to control the attitude of the satellite.
NASA Technical Reports Server (NTRS)
Gerdes, R. M.
1980-01-01
Results from a series of simulation and flight investigations undertaken to evaluate helicopter flying qualities and the effects of control system augmentation for nap-of-the-earth (NOE) agility and instrument flying tasks were analyzed to assess handling-quality factors common to both tasks. Precise attitude control was determined to be a key requirement for successful accomplishment of both tasks. Factors that degraded attitude controllability were improper levels of control sensitivity and damping and rotor-system cross-coupling due to helicopter angular rate and collective pitch input. Application of rate-command, attitude-command, and control-input decouple augmentation schemes enhanced attitude control and significantly improved handling qualities for both tasks. NOE agility and instrument flying handling-quality considerations, pilot rating philosophy, and supplemental flight evaluations are also discussed.
Low drag attitude control for Skylab orbital lifetime extension
NASA Technical Reports Server (NTRS)
Glaese, J. R.; Kennel, H. F.
1981-01-01
In the fall of 1977 it was determined that Skylab had started to tumble and that the original orbit lifetime predictions were much too optimistic. A decision had to be made whether to accept an early uncontrolled reentry with its inherent risks or try to attempt to control Skylab to a lower drag attitude in the hope that there was enough time to develop a Teleoperator Retrieval System, bring it up on the Space Shuttle and then decide whether to boost Skylab to a higher longer life orbit or to reenter it in a controlled fashion. The end-on-velocity (EOVV) control method is documented, which was successfully applied for about half a year to keep Skylab in a low drag attitude with the aid of the control moment gyros and a minimal expenditure of attitude control gas.
NASA Astrophysics Data System (ADS)
Liang, Xin-xin; Zhang, Nai-min; Zhang, Yan
2016-07-01
For solid launch vehicle performance promotion, a modeling method of interior and exterior ballistics associated optimization with constraints of attitude control and mechanical-thermal condition is proposed. Firstly, the interior and external ballistic models of the solid launch vehicle are established, and the attitude control model of the high wind area and the stage of the separation is presented, and the load calculation model of the drag reduction device is presented, and thermal condition calculation model of flight is presented. Secondly, the optimization model is established to optimize the range, which has internal and external ballistic design parameters as variables selected by sensitivity analysis, and has attitude control and mechanical-thermal conditions as constraints. Finally, the method is applied to the optimal design of a three stage solid launch vehicle simulation with differential evolution algorithm. Simulation results are shown that range capability is improved by 10.8%, and both attitude control and mechanical-thermal conditions are satisfied.
Research on Robot Pose Control Technology Based on Kinematics Analysis Model
NASA Astrophysics Data System (ADS)
Liu, Dalong; Xu, Lijuan
2018-01-01
In order to improve the attitude stability of the robot, proposes an attitude control method of robot based on kinematics analysis model, solve the robot walking posture transformation, grasping and controlling the motion planning problem of robot kinematics. In Cartesian space analytical model, using three axis accelerometer, magnetometer and the three axis gyroscope for the combination of attitude measurement, the gyroscope data from Calman filter, using the four element method for robot attitude angle, according to the centroid of the moving parts of the robot corresponding to obtain stability inertia parameters, using random sampling RRT motion planning method, accurate operation to any position control of space robot, to ensure the end effector along a prescribed trajectory the implementation of attitude control. The accurate positioning of the experiment is taken using MT-R robot as the research object, the test robot. The simulation results show that the proposed method has better robustness, and higher positioning accuracy, and it improves the reliability and safety of robot operation.
Solar Sail Attitude Control Performance Comparison
NASA Technical Reports Server (NTRS)
Bladt, Jeff J.; Lawrence, Dale A.
2005-01-01
Performance of two solar sail attitude control implementations is evaluated. One implementation employs four articulated reflective vanes located at the periphery of the sail assembly to generate control torque about all three axes. A second attitude control configuration uses mass on a gimbaled boom to alter the center-of-mass location relative to the center-of-pressure producing roll and pitch torque along with a pair of articulated control vanes for yaw control. Command generation algorithms employ linearized dynamics with a feedback inversion loop to map desired vehicle attitude control torque into vane and/or gimbal articulation angle commands. We investigate the impact on actuator deflection angle behavior due to variations in how the Jacobian matrix is incorporated into the feedback inversion loop. Additionally, we compare how well each implementation tracks a commanded thrust profile, which has been generated to follow an orbit trajectory from the sun-earth L1 point to a sub-L1 station.
Psychological mechanisms underlying doping attitudes in sport: motivation and moral disengagement.
Hodge, Ken; Hargreaves, Elaine A; Gerrard, David; Lonsdale, Chris
2013-08-01
We examined whether constructs outlined in self-determination theory (Deci & Ryan, 2002), namely, autonomy-supportive and controlling motivational climates and autonomous and controlled motivation, were related to attitudes toward performance-enhancing drugs (PEDs) in sport and drug-taking susceptibility. We also investigated moral disengagement as a potential mediator. We surveyed a sample of 224 competitive athletes (59% female; M age = 20.3 years; M = 10.2 years of experience participating in their sport), including 81 elite athletes. Using structural equation modeling analyses, our hypothesis proposing positive relationships with controlling climates, controlled motivation, and PEDs attitudes and susceptibility was largely supported, whereas our hypothesis proposing negative relationships among autonomous climate, autonomous motivation, and PEDs attitudes and susceptibility was not supported. Moral disengagement was a strong predictor of positive attitudes toward PEDs, which, in turn, was a strong predictor of PEDs susceptibility. These findings are discussed from both motivational and moral disengagement viewpoints.
Adaptive control applied to Space Station attitude control system
NASA Technical Reports Server (NTRS)
Lam, Quang M.; Chipman, Richard; Hu, Tsay-Hsin G.; Holmes, Eric B.; Sunkel, John
1992-01-01
This paper presents an adaptive control approach to enhance the performance of current attitude control system used by the Space Station Freedom. The proposed control law was developed based on the direct adaptive control or model reference adaptive control scheme. Performance comparisons, subject to inertia variation, of the adaptive controller and the fixed-gain linear quadratic regulator currently implemented for the Space Station are conducted. Both the fixed-gain and the adaptive gain controllers are able to maintain the Station stability for inertia variations of up to 35 percent. However, when a 50 percent inertia variation is applied to the Station, only the adaptive controller is able to maintain the Station attitude.
Larsson, Maria E H; Kreuter, Margareta; Nordholm, Lena
2010-07-01
Musculoskeletal disorders are prevalent and a major burden on individuals and society. Information on relationships of patient involvement and responsibility to outcome is limited. This study aimed to explore relationships between self-reported outcome of physiotherapy treatment and attitudes toward responsibility for musculoskeletal disorders. A cross-sectional postal survey design was used. Patients (n=615) from an outpatient physiotherapy clinic, who had finished their physiotherapy treatment within the last 6 months were sent a questionnaire that included the Attitudes regarding Responsibility for Musculoskeletal disorders instrument (ARM), self-reported outcome of treatment and sociodemographic data. A total of 279 (45%) completed forms were returned. Multiple logistic regression analysis was used. The patients' scores on the four dimensions of ARM ("responsibility self active," "responsibility out of my hands," "responsibility employer," and "responsibility medical professionals"), controlled for age, sex, education, and physical activity as well as for number of treatments, main treatment, and physiotherapist, were associated with the patients' self-reported treatment outcome. Patients who attributed responsibility more to themselves were more likely (OR 2.37 and over) to report considerable improvement as the outcome of physiotherapy treatment. Because this study was conducted at only one physiotherapy outpatient clinic and had a cross-sectional design, the results should be replicated in other settings. Because patients' attitudes regarding responsibility for musculoskeletal disorders can possibly affect the outcome of physiotherapy treatment, it might be useful to decide whether to systematically try to influence the person's attitude toward responsibility for the management of the disorder or to match treatment to attitude.
NASA Astrophysics Data System (ADS)
Ferri, Paolo; Accomazzo, Andrea; Hubault, Armelle; Lodiot, Sylvain; Pellon-Bailon, Jose-Luis; Porta, Roberto
2012-10-01
The International Rosetta Mission was launched on 2nd March 2004 on its 10 years journey to comet 67P/Churyumov-Gerasimenko. Rosetta will reach the comet in 2014, orbit it for about 1.5 years down to distances of a few kilometres and deliver the Lander Philae onto its surface. Following the fly-by of Asteroid (21-)Lutetia in 2010, Rosetta continued its travel towards the planned comet encounter in 2014. In this phase Rosetta became the solar-powered spacecraft that reached the largest Sun distances in history of spaceflight, up to an aphelion at 5.3 AU in October 2012. At distances above 4.5 AU the spacecraft's solar generator power is not sufficient to keep all spacecraft systems active. Therefore in June 2011 the spacecraft was spun up to provide gyroscopic stabilisation, and most of its on-board units, including those used for attitude control and communications, were switched off. Over this "hibernation" phase of about 2.5 years the spacecraft will keep a minimum of autonomy active to ensure maintenance of safe thermal conditions. After Lutetia fly-by, flight controllers had to tackle two anomalies that had significant impacts on the mission operations. A leak in the reaction control subsystem was confirmed and led to the re-definition of the operational strategy to perform the comet rendezvous manoeuvres planned for 2011 and 2014. Anomalous jumps detected in the estimated friction torque of two of the four reaction wheels used for attitude control forced the rapid adoption of measures to slow down the wheels degradation. This included in-flight re-lubrication activities and changes in the wheels operational speed regime. Once the troubleshooting of the two anomalies was completed, and the related operational scenarios were implemented, the first large (790 m/s) comet rendezvous manoeuvre was executed, split into several long burns in January and February 2011. The second burn was unexpectedly interrupted due to the anomalous behaviour of two thrusters, causing attitude off-pointing. Flight controllers modified the thrusters operation parameters in the on-board software and managed to re-start the sequence of burns and successfully complete the manoeuvre. After the manoeuvre, preparation for the critical spin-up and hibernation entry activities, planned for June 2011, began. This paper presents the activities carried out on Rosetta in the final year before hibernation entry. The major anomalies and the related troubleshooting and workaround solutions are detailed. Lessons learned from the operation of the first spacecraft operating with solar power at Jupiter-like distances from the Sun are presented and discussed.
Xu, Xianglong; Leung, Doris Yin Ping; Li, Bing; Wang, Pengfei; Zhao, Yong
2015-01-19
Smoking has resulted in numerous deaths in China. Data indicate that 21% of college students in China are smokers. This study aimed to examine the smoking-related behaviors of undergraduates, as influenced by knowledge, attitude, social pressure, and environmental constraints. A convenience sampling of 412 fresh undergraduates from two universities in the University Town in Chongqing, China was recruited. Chi-square tests were used to compare the smoking-related variables between smokers and non-smokers. Moreover, logistic regression was used to examine the factors that associated with smoking status in undergraduates. Smokers and non-smokers differ in terms of knowledge, attitudes toward smoking, participation in tobacco promotional activities, and sources of social pressure. Logistic regression model identified that sex, living cost, five smoking-related attitudes of "Smoking is pleasurable, Smoking relaxes me, Smoking makes me look strong, Smoking is a waste of money, Smoking can help me study better", the social pressure "Smoking brings comfort during celebration", and the environmental constraints "How did you get your cigarettes in the past 30 days?" are significantly associated with smoking. The findings provide a better understanding of the epidemic of smoking among fresh undergraduates in Chongqing, China. This study provides more detailed consideration of the implications for the WHO Framework Convention on Tobacco Control (FCTC) policies, especially on restriction of retail sales outlets and tobacco promotion activities near universities in China.
Tesson, Stephanie; Sundaresan, Puma; Ager, Brittany; Butow, Phyllis; Kneebone, Andrew; Costa, Daniel; Woo, Henry; Pearse, Maria; Juraskova, Ilona; Turner, Sandra
2016-04-01
The RAVES (Trans-Tasman Radiation Oncology Group 08.03) randomised controlled trial (RCT), compares adjuvant radiotherapy with early salvage radiotherapy in men with high risk histopathological features at prostatectomy. The RAVES Decision Aid study evaluates the utility of a decision aid for men considering participation in the RAVES RCT. We report the RAVES Decision Aid study participants' attitudes and knowledge regarding RCTs, decision-making preferences and decisional-conflict. Baseline questionnaires assessed knowledge and attitudes towards RCTs and RAVES RCT. Sociodemographic and clinical predictors of knowledge were examined. Involvement in decision-making and difficulties with the decision-making process were assessed using validated tools. 127 men (median age=63years) were recruited through urologists (n=91) and radiation oncologists (n=36). Men preferred collaborative (35%) or semi-active (35%) decision-making roles. Most (>75%) felt the RAVES RCT was worthwhile and important with participation being wise. However, nearly half had high decisional-conflict regarding participation. Scores of objective knowledge regarding RCTs and RAVES RCT were low. Most men with high-risk histopathological features at prostatectomy desire active involvement in decision-making regarding further management. Despite positive attitudes towards RCTs and the RAVES RCT, there were gaps in knowledge and high decisional-conflict surrounding participation. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.
LQG/LTR Optimal Attitude Control of Small Flexible Spacecraft Using Free-Free Boundary Conditions
2006-08-03
particular on attitude control of flex- ible space structures. Croopnick et al .[50] present a literature survey in the areas of attitude control...modeling and control of space structures is compiled by Nurre et al .[161]. One important thing to note from the surveys listed above is the 21 focus on the...papers surveyed by Croopnick et al . in 1979, by Meirovitch in 1979, Balas in 1982, and Nurre et al . in 1984. The focus of the papers included in all
ERIC Educational Resources Information Center
Barrell, G. V.; Holt, D.
1982-01-01
A longitudinal investigation of the attitudes towards physical activity of specialist students of physical education was undertaken during a course of training teachers. Significant changes of attitude with time were noted, particularly in the Vertigo and Ascetic dimensions. (Author)
A preliminary 6 DOF attitude and translation control system design for Starprobe
NASA Technical Reports Server (NTRS)
Mak, P.; Mettler, E.; Vijayarahgavan, A.
1981-01-01
The extreme thermal environment near perihelion and the high-accuracy gravitational science experiments impose unique design requirements on various subsystems of Starprobe. This paper examines some of these requirements and their impact on the preliminary design of a six-degree-of-freedom attitude and translational control system. Attention is given to design considerations, the baseline attitude/translational control system, system modeling, and simulation studies.
NASA Astrophysics Data System (ADS)
Aleksandrov, A. Yu.; Aleksandrova, E. B.; Tikhonov, A. A.
2018-07-01
The paper deals with a dynamically symmetric satellite in a circular near-Earth orbit. The satellite is equipped with an electrodynamic attitude control system based on Lorentz and magnetic torque properties. The programmed satellite attitude motion is such that the satellite slowly rotates around the axis of its dynamical symmetry. Unlike previous publications, we consider more complex and practically more important case where the axis is fixed in the orbital frame in an inclined position with respect to the local vertical axis. The satellite stabilization in the programmed attitude motion is studied. The gravitational disturbing torque acting on the satellite attitude dynamics is taken into account since it is the largest disturbing torque. The novelty of the proposed approach is based on the usage of electrodynamic attitude control system. With the aid of original construction of a Lyapunov function, new conditions under which electrodynamic control solves the problem are obtained. Sufficient conditions for asymptotic stability of the programmed motion are found in terms of inequalities for the values of control parameters. The results of a numerical simulation are presented to demonstrate the effectiveness of the proposed approach.
Regolisti, Giuseppe; Maggiore, Umberto; Sabatino, Alice; Gandolfini, Ilaria; Pioli, Sarah; Torino, Claudia; Aucella, Filippo; Cupisti, Adamasco; Pistolesi, Valentina; Capitanini, Alessandro; Caloro, Giorgia; Gregorini, Mariacristina; Battaglia, Yuri; Mandreoli, Marcora; Dani, Lucia; Mosconi, Giovanni; Bellizzi, Vincenzo; Di Iorio, Biagio Raffaele; Conti, Paolo; Fiaccadori, Enrico
2018-01-01
In hemodialysis patients, sedentarism is a potentially modifiable mortality risk factor. We explored whether healthcare staff's attitude towards exercise interacts with patient-perceived barriers in modifying the level of physical activity in this population. In this prospective, cross-sectional, multicenter study we recruited 608 adult patients and 330 members of the healthcare staff in 16 hemodialysis units in Italy. We assessed patient-perceived barriers to, and healthcare staff's attitude towards, exercise by specific questionnaires. We fitted multilevel linear models to analyze the relationships of either barriers or staff's attitude, and their interaction, with a measure of patient self-reported physical activity (the Human Activity Profile-Adjusted Activity Score [HAP-AAS]), adjusting for multiple confounders. We also employed latent class analysis to dichotomize patients into those endorsing or not endorsing barriers. Most barriers were negatively associated with the HAP-AAS (adjusted change attributable to a given barrier ranging between -5.1 ["Feeling too old", 95% Confidence Interval: -9.4 to -0.8] and -15.6 ["Ulcers on legs and feet", 95%CI: -24.8 to -6.5]. We found a significant interaction between staff's attitude and barriers (adjusted P values ranging between 0.03 ["I do not believe that it is physician's or nurse's role providing advice on exercise to patients on dialysis"] and 0.001 ["I do not often ask patients about exercise"]). A beneficial effect of a proactive staff's attitude was evident only in patients not endorsing barriers. Barriers and non-proactive staff's attitude reduce physical activity in hemodialysis patients. Patients not endorsing barriers benefit the most from a proactive staff's attitude.
NASA Technical Reports Server (NTRS)
Wirzburger, John H.
2005-01-01
For f i h years, the science mission of the Hubble Space Telescope (HST) required using at least three of six rate gyros for attitude control. In the past, HST has mitigated gyro hardware failures by replacement of the failed units through Space Shuttle Servicing Missions. Following the tragic loss of Space Shuttle Columbia on STS-107, the desire to have a safe haven for astronauts during missions has resulted in the cancellation of all planned maxu14 missions to HST. While a robotic servicing mission is being currently being planned, controlling with alternate sensors to replace failed gyros can extend the HST Science mission until the robotic mission can be performed and extend science at HST s end of life. A two-gym control law has been designed and implemented using magnetometers (Magnetic Sensing System - MSS), fixed head star trackers (FHSTs), and Fine Guidance Sensors (FGSs) to control vehicle rate about the missing gyro axis. The three aforementioned sensors are used in succession to reduce HST boresight jitter to less than 7 milli-arcseconds rms and attitude error to less than 10 milli-arcseconds prior to science imaging. The MSS and 2-Gyro (M2G) control law is used for large angle maneuvers and attitude control during earth occultation of FHSTs and FGSs. The Tracker and 2-Gyro (T2G) control law dampens M2G rates and corrects the majority of attitude error in preparation for guide star acquisition with the FGSs. The Fine Guidance Sensor and 2-Gyro (F2G) control law d a m p T2G rates and controls HST attitude during science imaging. This paper describes the M2G control law. Details of M2G algorithms are presented, including computation of the HST 3-axis attitude error estimate, design of the M2G control law, SISO hear stability analyses, and restrictions on operations to maintain the h d t h and safety requirement of a 10degree maximum attitude error. Results of simulations performed in HSTSIM, a high-fidelity non-linear time domain simulation, are presented to predict HST on-orbit performance in attitude hold and maneuver modes. Simulation results are compared to on-orbit data from M2G flight tests performed in November and December 2004 and February 2005. Flight telemetry, using a currently available third gyro, shows that HST attitude error with the new M2G control law is maintained below the 10-degree requirement, and attitude errors are under 2 degrees for 95% of the time.
Blake, Kelly D; Viswanath, K; Blendon, Robert J; Vallone, Donna
2010-02-01
In August 2007, the President's Cancer Panel urged the leadership of the nation to "summon the political will to address the public health crisis caused by tobacco use" (President's Cancer Panel, N, 2007, Promoting healthy lifestyles: Policy, program, and personal recommendations for reducing cancer risk. http://deainfo.nci.nih.gov/advisory/pcp/pcp07rpt/pcp07rpt.pdf). While some research has examined predictors of public support for tobacco control measures, little research has examined modifiable factors that may influence public attitudes toward tobacco control. We used the American Legacy Foundation's 2003 American Smoking and Health Survey 2 to examine the contribution of smoking status, knowledge of the negative effects of tobacco, and tobacco-specific media exposure (antitobacco messages, news coverage of tobacco issues, and protobacco advertising) on U.S. adults' attitudes toward tobacco control. In addition, we assessed whether smoking status moderates the relationship between tobacco-specific media exposure and policy attitudes. Weighted multivariable logistic regression models were employed. Results suggest that knowledge of the negative effects of tobacco and smoking status are associated with attitudes toward tobacco control and that exposure to tobacco-specific information in the media plays a role only in some instances. We found no evidence of effect modification by smoking status on the impact of exposure to tobacco-specific media on attitudes toward tobacco control. Understanding the impact of readily modifiable factors that shape policy attitudes is essential if we are to target outreach and education in a way that is likely to sway public support for tobacco control.
Child and Caregiver Attitudes About Sports Drinks and Weekly Sports Drink Intake Among U.S. Youth.
Zytnick, Deena; Park, Sohyun; Onufrak, Stephen J
2016-01-01
To examine caregiver and youth attitudes about sports drinks (SDs) and the association of those attitudes with youth SD intake. Study design was cross-sectional. The online YouthStyles survey was sent to youth (ages 12-17 years) whose caregivers completed the online Summer ConsumerStyles survey for adults. The 2011 Styles survey data comprised the setting. The sample was composed of 815 U.S. caregiver-youth dyads. The outcome variable is youth SD consumption, and exposure variables are youth and caregivers' attitudes that SDs are healthy for children, and caregivers' attitude that children need SDs for hydration. Covariates are youth demographic and physical activity variables. Multivariable logistic regression was used to estimate adjusted odds ratios (ORs) for youth SD consumption one or more times per week after controlling for covariates. About one in five youth consumed SDs one or more times per week. Caregiver attitudes about the healthfulness of SDs and children's need of SDs for hydration both significantly differed by race and caregiver education level. The odds of youth SD consumption one or more times per week were significantly higher among youth of caregivers who agreed that SDs are good, healthy drinks for children (OR, 2.72 vs. disagreed) and among youth of caregivers who agreed that children need SDs for hydration (OR, 3.15 vs. disagreed). Youth attitude about SD healthfulness was not associated with intake. Caregivers, particularly minority and less educated caregivers, may need more education about SD use.
Zong, Qun; Shao, Shikai
2016-11-01
This paper investigates decentralized finite-time attitude synchronization for a group of rigid spacecraft by using quaternion with the consideration of environmental disturbances, inertia uncertainties and actuator saturation. Nonsingular terminal sliding mode (TSM) is used for controller design. Firstly, a theorem is proven that there always exists a kind of TSM that converges faster than fast terminal sliding mode (FTSM) for quaternion-descripted attitude control system. Controller with this kind of TSM has faster convergence and reduced computation than FTSM controller. Then, combining with an adaptive parameter estimation strategy, a novel terminal sliding mode disturbance observer is proposed. The proposed disturbance observer needs no upper bound information of the lumped uncertainties or their derivatives. On the basis of undirected topology and the disturbance observer, decentralized attitude synchronization control laws are designed and all attitude errors are ensured to converge to small regions in finite time. As for actuator saturation problem, an auxiliary variable is introduced and accommodated by the disturbance observer. Finally, simulation results are given and the effectiveness of the proposed control scheme is testified. Copyright © 2016. Published by Elsevier Ltd.
MEMS Reaction Control and Maneuvering for Picosat Beyond LEO
NASA Technical Reports Server (NTRS)
Alexeenko, Alina
2016-01-01
The MEMS Reaction Control and Maneuvering for Picosat Beyond LEO project will further develop a multi-functional small satellite technology for low-power attitude control, or orientation, of picosatellites beyond low Earth orbit (LEO). The Film-Evaporation MEMS Tunable Array (FEMTA) concept initially developed in 2013, is a thermal valving system which utilizes capillary forces in a microchannel to offset internal pressures in a bulk fluid. The local vapor pressure is increased by resistive film heating until it exceeds meniscus strength in a nozzle which induces vacuum boiling and provides a stagnation pressure equal to vapor pressure at that point which is used for propulsion. Interplanetary CubeSats can utilize FEMTA for high slew rate attitude corrections in addition to desaturating reaction wheels. The FEMTA in cooling mode can be used for thermal control during high-power communication events, which are likely to accompany the attitude correction. Current small satellite propulsion options are limited to orbit correction whereas picosatellites are lacking attitude control thrusters. The available attitude control systems are either quickly saturated reaction wheels or movable high drag surfaces with long response times.
Improving Primary Teachers' Attitudes toward Science by Attitude-Focused Professional Development
ERIC Educational Resources Information Center
van Aalderen-Smeets, Sandra I.; van der Molen, Juliette H. Walma
2015-01-01
This article provides a description of a novel, attitude-focused, professional development intervention, and presents the results of an experimental pretest-posttest control group study investigating the effects of this intervention on primary teachers' personal attitudes toward science, attitudes toward teaching science, and their science…
Two Axis Pointing System (TAPS) attitude acquisition, determination, and control
NASA Technical Reports Server (NTRS)
Azzolini, John D.; Mcglew, David E.
1990-01-01
The Two Axis Pointing System (TAPS) is a 2 axis gimbal system designed to provide fine pointing of Space Transportation System (STS) borne instruments. It features center-of-mass instrument mounting and will accommodate instruments of up to 1134 kg (2500 pounds) which fit within a 1.0 by 1.0 by 4.2 meter (40 by 40 by 166 inch) envelope. The TAPS system is controlled by a microcomputer based Control Electronics Assembly (CEA), a Power Distribution Unit (PDU), and a Servo Control Unit (SCU). A DRIRU-II inertial reference unit is used to provide incremental angles for attitude propagation. A Ball Brothers STRAP star tracker is used for attitude acquisition and update. The theory of the TAPS attitude determination and error computation for the Broad Band X-ray Telescope (BBXRT) are described. The attitude acquisition is based upon a 2 star geometric solution. The acquisition theory and quaternion algebra are presented. The attitude control combines classical position, integral and derivative (PID) control with techniques to compensate for coulomb friction (bias torque) and the cable harness crossing the gimbals (spring torque). Also presented is a technique for an adaptive bias torque compensation which adjusts to an ever changing frictional torque environment. The control stability margins are detailed, with the predicted pointing performance, based upon simulation studies. The TAPS user interface, which provides high level operations commands to facilitate science observations, is outlined.
NASA Astrophysics Data System (ADS)
TayyebTaher, M.; Esmaeilzadeh, S. Majid
2017-07-01
This article presents an application of Model Predictive Controller (MPC) to the attitude control of a geostationary flexible satellite. SIMO model has been used for the geostationary satellite, using the Lagrange equations. Flexibility is also included in the modelling equations. The state space equations are expressed in order to simplify the controller. Naturally there is no specific tuning rule to find the best parameters of an MPC controller which fits the desired controller. Being an intelligence method for optimizing problem, Genetic Algorithm has been used for optimizing the performance of MPC controller by tuning the controller parameter due to minimum rise time, settling time, overshoot of the target point of the flexible structure and its mode shape amplitudes to make large attitude maneuvers possible. The model included geosynchronous orbit environment and geostationary satellite parameters. The simulation results of the flexible satellite with attitude maneuver shows the efficiency of proposed optimization method in comparison with LQR optimal controller.
Ofan, Renana H; Rubin, Nava; Amodio, David M
2011-10-01
We examined the relation between neural activity reflecting early face perception processes and automatic and controlled responses to race. Participants completed a sequential evaluative priming task, in which two-tone images of Black faces, White faces, and cars appeared as primes, followed by target words categorized as pleasant or unpleasant, while encephalography was recorded. Half of these participants were alerted that the task assessed racial prejudice and could reveal their personal bias ("alerted" condition). To assess face perception processes, the N170 component of the ERP was examined. For all participants, stronger automatic pro-White bias was associated with larger N170 amplitudes to Black than White faces. For participants in the alerted condition only, larger N170 amplitudes to Black versus White faces were also associated with less controlled processing on the word categorization task. These findings suggest that preexisting racial attitudes affect early face processing and that situational factors moderate the link between early face processing and behavior.
1999 Flight Mechanics Symposium
NASA Technical Reports Server (NTRS)
Lynch, John P. (Editor)
1999-01-01
This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on May 18-20, 1999. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to orbit-attitude prediction, determination, and control; attitude sensor calibration; attitude determination error analysis; attitude dynamics; and orbit decay and maneuver strategy. Government, industry, and the academic community participated in the preparation and presentation of these papers.
Does Exonerating an Accused Researcher Restore the Researcher's Credibility?
Greitemeyer, Tobias; Sagioglou, Christina
2015-01-01
Scientific misconduct appears to be on the rise. However, an accused researcher may later be exonerated. The present research examines to what extent participants adhere to their attitude toward a researcher who allegedly committed academic misconduct after learning that the researcher is innocent. In two studies, participants in an exoneration and an uncorrected accusation condition learned that the ethics committee of a researcher's university demanded the retraction of one of the researcher's articles, whereas participants in a control condition did not receive this information. As intended, this manipulation led to a more favorable attitude toward the researcher in the control compared to the exoneration and the uncorrected accusation conditions (pre-exoneration attitude). Then, participants in the exoneration condition learned that the researcher was exonerated and that the article was not retracted. Participants in the uncorrected accusation and the control condition were not informed about the exoneration. Results revealed that the exoneration effectively worked, in that participants in the exoneration condition had a more favorable attitude (post-exoneration attitude) toward the researcher than did participants in the uncorrected accusation condition. Moreover, the post-exoneration attitude toward the researcher was similar in the exoneration and the control conditions. Finally, in the exoneration condition only, participants' post-exoneration attitude was more favorable than their pre-exoneration attitude. These findings suggest that an exoneration of an accused researcher restores the researcher's credibility.
Brabers, Anne E M; de Jong, Judith D; Groenewegen, Peter P; van Dijk, Liset
2016-09-21
There is a growing emphasis towards including patients in medical decision-making. However, not all patients are actively involved in such decisions. Research has so far focused mainly on the influence of patient characteristics on preferences for active involvement. However, it can be argued that a patient's social context has to be taken into account as well, because social norms and resources affect behaviour. This study aims to examine the role of social resources, in the form of the availability of informational and emotional support, on the attitude towards taking an active role in medical decision-making. A questionnaire was sent to members of the Dutch Health Care Consumer Panel (response 70 %; n = 1300) in June 2013. A regression model was then used to estimate the relation between medical and lay informational support and emotional support and the attitude towards taking an active role in medical decision-making. Availability of emotional support is positively related to the attitude towards taking an active role in medical decision-making only in people with a low level of education, not in persons with a middle and high level of education. The latter have a more positive attitude towards taking an active role in medical decision-making, irrespective of the level of emotional support available. People with better access to medical informational support have a more positive attitude towards taking an active role in medical decision-making; but no significant association was found for lay informational support. This study shows that social resources are associated with the attitude towards taking an active role in medical decision-making. Strategies aimed at increasing patient involvement have to address this.
Lipstein, Ellen A; Kronman, Matthew P; Richmond, Camilla; White, Kristin Nyweide; Shugerman, Richard P; McPhillips, Heather A
2011-01-01
Background Hospital quality improvement initiatives are becoming increasingly common. Little is known about the influence of these initiatives on resident learning and attitudes. Our objective was to assess whether training in a hospital committed to involving residents in hospital-initiated, continuous quality improvement (CQI), and to participation in such activities, would influence residents' attitudes toward CQI and engagement in the hospital community. Methods We surveyed Seattle Children's Hospital pediatric residents, from residency graduation years 2002–2009. We included questions about participation in quality improvement activities during residency and measures of attitude toward CQI and of workplace engagement. We used descriptive statistics to assess trends in resident participation in hospital CQI activities, attitudes toward CQI and workplace engagement. Results The overall response rate was 84% (162 of 194). Among graduated residents, there was a significant trend toward increased participation in CQI activities (P = .03). We found no difference in attitude toward CQI between those who had and those who had not participated in such activities nor between residents who began training before and those who began after the hospital formally committed to CQI. Sixty-three percent of residents (25 of 40) who participated in CQI activities were engaged in the hospital community compared with 53% (57 of 107) who did not participate in CQI activities (P = .21). Conclusions Training in a hospital committed to involving residents in CQI was associated with a high rate of participation in CQI activities. Although such training and participation in CQI were not associated with resident attitudes toward CQI or hospital engagement, it may allow residents to learn skills for practice-based learning and improvement and systems-based practice. PMID:22942955
Ferreira, Gabriela; Pereira, M Graça
2017-09-01
This study focused on the contribution of the extended theory of planned behavior regarding intention to perform physical activity, adherence to physical activity, and its mediator role in the relationship between trust in the physician and adherence to physical activity, in a sample of 120 patients with type 2 diabetes. The results revealed that positive attitudes and perception of control predicted a stronger intention to do physical activity. The intention to do physical activity was the only predictor of adherence to physical activity. Planning mediated the relationship between trust in the physician and adherence. Implications for patients with type 2 diabetes are discussed.
Parental attitudes and aggression in the Emo subculture.
Chęć, Magdalena; Potemkowski, Andrzej; Wąsik, Marta; Samochowiec, Agnieszka
2016-01-01
A better functioning of adolescents involves proper relationships with parents, whereas negative relationships lead to aggressive behaviour. Young members of Emo subculture, characterised by deep emotional sensitivity, are particularly vulnerable to parental influence. The aim was to specify a relationship between parental attitudes and aggression among adolescents from the Emo subculture in comparison with a control group. 3,800 lower secondary school students took part in the introductory research. A target group constituted 41 people from the Emo subculture as well as a control group involving 48 people. A screening survey, the Parental Attitudes Scale, the Aggression Questionnaire and the author's questionnaire including questions concerning the functioning in the Emo subculture were used in the study. The results obtained in the research study suggest that there is a relationship between the indicated improper parental attitudes and aggressive behaviour among adolescents from the Emo subculture in comparison with the control group. In the Emo subculture, teenagers'aggressive behaviour is related to improper parental attitudes. It has been stated that mother's attitudes, irrespective of subculture, are much more strongly associated with the aggression among adolescents than father's attitudes. Moreover, aggressive behaviour in the Emo subculture occurs when father displays an excessively demanding attitude. A reduction of the level of almost all kinds of aggression manifested among teenagers from the Emo subculture is associated with mothers' attitude of acceptance. Mothers' autonomous attitude leads to an increase in the aggression in this group, whereas an inconsistent attitude of mothers fosters an increase in aggression among all teenagers.
Cold Gas Reaction Control System for the Near Earth Asteroid Scout CubeSat
NASA Technical Reports Server (NTRS)
Stiltner, Brandon C.; Diedrich, Ben; Becker, Chris; Bertaska, Ivan; Heaton, Andrew; Orphee, Juan
2017-01-01
This paper describes the Attitude Control System (ACS) for the Near Earth Asteroid (NEA) Scout cubesat with particular focus on the Reaction Control System (RCS). NEA Scout is a 6-Unit cubesat with an 86-square-meter solar sail. NEA Scout will launch on Space Launch System (SLS) Exploration Mission 1 (EM-1), currently scheduled to launch in 2019. The spacecraft will rendezvous with an asteroid after a two year journey, and will conduct science imagery. The ACS consists of three major actuating subsystems: a Reaction Wheel (RW) control system, a Reaction Control System (RCS), and an Active Mass Translator (AMT) system. The three subsystems allow for a wide range of spacecraft attitude control capabilities, needed for the different phases of the NEA-Scout mission. The RCS performs a number of critical functions during NEA Scout’s mission. These requirements are described and the performance for achieving these requirements is shown. Moreover, NEA Scout employs a solar sail for long-duration propulsion. Solar sails are large, flexible structures that typically have low bending-mode frequencies. This paper demonstrates a robust performance while avoiding excitation of the sail’s structural modes.
NASA Technical Reports Server (NTRS)
Orphee, Juan; Heaton, Andrew; Diedrich, Ben; Stiltner, Brandon C.
2018-01-01
A novel mechanism, the Active Mass Translator (AMT), has been developed for the NASA Near Earth Asteroid (NEA) Scout mission to autonomously manage the spacecraft momentum. The NEA Scout CubeSat will launch as a secondary payload onboard Exploration Mission 1 of the Space Launch System. To accomplish its mission, the CubeSat will be propelled by an 86 square-meter solar sail during its two-year journey to reach asteroid 1991VG. NEA Scout's primary attitude control system uses reaction wheels for holding attitude and performing slew maneuvers, while a cold gas reaction control system performs the initial detumble and early trajectory correction maneuvers. The AMT control system requirements, feedback architecture, and control performance will be presented. The AMT reduces the amount of reaction control propellant needed for momentum management and allows for smaller capacity reaction wheels suitable for the limited 6U spacecraft volume. The reduced spacecraft mass allows higher in-space solar sail acceleration, thus reducing time-of-flight. The reduced time-of-flight opens the range of possible missions, which is limited by the lifetime of typical non-radiation tolerant CubeSat avionics exposed to the deep-space environment.
Cold Gas Reaction Control System for the Near Earth Asteroid Scout CubeSat
NASA Technical Reports Server (NTRS)
Stiltner, Brandon C.; Diedrich, Ben; Orphee, Juan; Heaton, Andrew; Becker, Chris; Bertaska, Ivan
2017-01-01
This paper describes the Attitude Control System (ACS) for the Near Earth Asteroid (NEA) Scout cubesat with particular focus on the Reaction Control System (RCS). NEA Scout is a 6U cubesat with an 86 square-meter solar sail. NEA Scout will launch on Space Launch System (SLS) Exploration Mission 1 (EM-1), currently scheduled to launch in 2018. The spacecraft will rendezvous with an asteroid after a two year journey, and will conduct science imagery. The ACS consists of three major actuating subsystems: a Reaction Wheel (RW) control system, a Reaction Control System (RCS), and an Active Mass Translator (AMT) system. The three subsystems allow for a wide range of spacecraft attitude control capabilities, needed for the different phases of the NEA-Scout mission. The RCS performs a number of critical functions during NEA Scout's mission. These requirements are described and the performance for achieving these requirements is shown. Moreover, NEA Scout employs a solar sail for long-duration propulsion. Solar sails are large, flexible structures that typically have low bending-mode frequencies. This paper demonstrates a robust performance while avoiding excitation of the sail's structural modes.
González-González, Ana Isabel; Orrego, Carola; Perestelo-Perez, Lilisbeth; Bermejo-Caja, Carlos Jesús; Mora, Nuria; Koatz, Débora; Ballester, Marta; Del Pino, Tasmania; Pérez-Ramos, Jeannet; Toledo-Chavarri, Ana; Robles, Noemí; Pérez-Rivas, Francisco Javier; Ramírez-Puerta, Ana Belén; Canellas-Criado, Yolanda; Del Rey-Granado, Yolanda; Muñoz-Balsa, Marcos José; Becerril-Rojas, Beatriz; Rodríguez-Morales, David; Sánchez-Perruca, Luis; Vázquez, José Ramón; Aguirre, Armando
2017-10-30
Communities of practice are based on the idea that learning involves a group of people exchanging experiences and knowledge. The e-MPODERA project aims to assess the effectiveness of a virtual community of practice aimed at improving primary healthcare professional attitudes to the empowerment of patients with chronic diseases. This paper describes the protocol for a cluster randomized controlled trial. We will randomly assign 18 primary-care practices per participating region of Spain (Catalonia, Madrid and Canary Islands) to a virtual community of practice or to usual training. The primary-care practice will be the randomization unit and the primary healthcare professional will be the unit of analysis. We will need a sample of 270 primary healthcare professionals (general practitioners and nurses) and 1382 patients. We will perform randomization after professionals and patients are selected. We will ask the intervention group to participate for 12 months in a virtual community of practice based on a web 2.0 platform. We will measure the primary outcome using the Patient-Provider Orientation Scale questionnaire administered at baseline and after 12 months. Secondary outcomes will be the sociodemographic characteristics of health professionals, sociodemographic and clinical characteristics of patients, the Patient Activation Measure questionnaire for patient activation and outcomes regarding use of the virtual community of practice. We will calculate a linear mixed-effects regression to estimate the effect of participating in the virtual community of practice. This cluster randomized controlled trial will show whether a virtual intervention for primary healthcare professionals improves attitudes to the empowerment of patients with chronic diseases. ClicalTrials.gov, NCT02757781 . Registered on 25 April 2016. Protocol Version. PI15.01 22 January 2016.
Dodd, Alyson L; Mansell, Warren; Sadhnani, Vaneeta; Morrison, Anthony P; Tai, Sara
2010-01-01
An integrative cognitive model proposed that ascribing extreme personal appraisals to changes in internal state is key to the development of the symptoms of bipolar disorder. The Hypomanic Attitudes and Positive Predictions Inventory (HAPPI) was developed to measure these appraisals. The aim of the current study was to validate an expanded 61-item version of the HAPPI. In a largely female student sample (N = 134), principal components analysis (PCA) was performed on the HAPPI. Associations between the HAPPI and analogue bipolar symptoms after 3 months were examined. PCA of the HAPPI revealed six categories of belief: Self Activation, Self-and-Other Critical, Catastrophic, Extreme Appraisals of Social Approval, Appraisals of Extreme Agitation, and Loss of Control. The HAPPI predicted all analogue measures of hypomanic symptoms after 3 months when controlling for baseline symptoms. In a more stringent test incorporating other psychological measures, the HAPPI was independently associated only with activation (e.g. thoughts racing) at 3 months. Dependent dysfunctional attitudes predicted greater conflict (e.g. irritability), depression and reduced well-being, hypomanic personality predicted self-reported diagnostic bipolar symptoms, and behavioural dysregulation predicted depression. Extreme beliefs about internal states show a modest independent association with prospective analogue bipolar symptoms, alongside other psychological factors. Further work will be required to improve the factor structure of the HAPPI and study its validity in clinical samples.
Bisallah, Chindo Ibrahim; Lye, Munn-Sann; Mohd Sidik, Sherina; Ibrahim, Normala; Iliyasu, Zubairu; Onyilo, Michael Ochigbo
2018-01-01
Introduction The risk of development of active TB in HIV-infected individuals is 20–37 times higher than those that are HIV negative. Poor knowledge of TB amongst people living with HIV has been associated with high transmission. Objectives To determine the effectiveness of a new health education intervention module in improving knowledge, attitude, and practice (KAP) regarding tuberculosis among HIV patients in General Hospital Minna, Nigeria. Methods A randomized control trial was carried out from July 2015 to June 2017. A random number generating program was used to allocate 226 respondents into 2 groups. The intervention group received health education regarding tuberculosis using the developed module. The control group received the normal services provided for HIV patients. Data were collected from December 2015 to September 2016 at baseline, immediate post intervention, three, six and nine months. The outcome measures were knowledge, attitude, and practice. Results There was no significant difference with respect to socio-demographic characteristics, KAP of the respondents in the intervention and control group at baseline. However, there was significant improvement in knowledge in the intervention group compared to the control group, group main effect (F = (1,218) = 665.889, p = 0.001, partial ἠ2 = 0.753, d = 5.4); time (F = (3.605, 218) = 52.046, p = 0.001, partial ἠ2 = 0.193, d = 1.52) and interaction between group with time (F = (3.605, 218) = 34.028, p = 0.001, partial ἠ2 = 0.135, d = 1.23). Likewise, there was significant improvement in attitude, group main effect (p = 0.001, d = 1.26) and time (p = 0.001, p, d = 0.65). Similarly, there was improvement in practice, group main effect, time, and interaction of group with time (p < 0.05). Conclusion The health education intervention program was effective in improving KAP regarding tuberculosis among HIV patients. PMID:29470530
Bisallah, Chindo Ibrahim; Rampal, Lekhraj; Lye, Munn-Sann; Mohd Sidik, Sherina; Ibrahim, Normala; Iliyasu, Zubairu; Onyilo, Michael Ochigbo
2018-01-01
The risk of development of active TB in HIV-infected individuals is 20-37 times higher than those that are HIV negative. Poor knowledge of TB amongst people living with HIV has been associated with high transmission. To determine the effectiveness of a new health education intervention module in improving knowledge, attitude, and practice (KAP) regarding tuberculosis among HIV patients in General Hospital Minna, Nigeria. A randomized control trial was carried out from July 2015 to June 2017. A random number generating program was used to allocate 226 respondents into 2 groups. The intervention group received health education regarding tuberculosis using the developed module. The control group received the normal services provided for HIV patients. Data were collected from December 2015 to September 2016 at baseline, immediate post intervention, three, six and nine months. The outcome measures were knowledge, attitude, and practice. There was no significant difference with respect to socio-demographic characteristics, KAP of the respondents in the intervention and control group at baseline. However, there was significant improvement in knowledge in the intervention group compared to the control group, group main effect (F = (1,218) = 665.889, p = 0.001, partial ἠ2 = 0.753, d = 5.4); time (F = (3.605, 218) = 52.046, p = 0.001, partial ἠ2 = 0.193, d = 1.52) and interaction between group with time (F = (3.605, 218) = 34.028, p = 0.001, partial ἠ2 = 0.135, d = 1.23). Likewise, there was significant improvement in attitude, group main effect (p = 0.001, d = 1.26) and time (p = 0.001, p, d = 0.65). Similarly, there was improvement in practice, group main effect, time, and interaction of group with time (p < 0.05). The health education intervention program was effective in improving KAP regarding tuberculosis among HIV patients.
X-33 Attitude Control Using the XRS-2200 Linear Aerospike Engine
NASA Technical Reports Server (NTRS)
Hall, Charles E.; Panossian, Hagop V.
1999-01-01
The Vehicle Control Systems Team at Marshall Space Flight Center, Structures and Dynamics Laboratory, Guidance and Control Systems Division is designing, under a cooperative agreement with Lockheed Martin Skunkworks, the Ascent, Transition, and Entry flight attitude control systems for the X-33 experimental vehicle. Test flights, while suborbital, will achieve sufficient altitudes and Mach numbers to test Single Stage To Orbit, Reusable Launch Vehicle technologies. Ascent flight control phase, the focus of this paper, begins at liftoff and ends at linear aerospike main engine cutoff (MECO). The X-33 attitude control system design is confronted by a myriad of design challenges: a short design cycle, the X-33 incremental test philosophy, the concurrent design philosophy chosen for the X-33 program, and the fact that the attitude control system design is, as usual, closely linked to many other subsystems and must deal with constraints and requirements from these subsystems. Additionally, however, and of special interest, the use of the linear aerospike engine is a departure from the gimbaled engines traditionally used for thrust vector control (TVC) in launch vehicles and poses certain design challenges. This paper discusses the unique problem of designing the X-33 attitude control system with the linear aerospike engine, requirements development, modeling and analyses that verify the design.
Novel approach to improve the attitude update rate of a star tracker.
Zhang, Shuo; Xing, Fei; Sun, Ting; You, Zheng; Wei, Minsong
2018-03-05
The star tracker is widely used in attitude control systems of spacecraft for attitude measurement. The attitude update rate of a star tracker is important to guarantee the attitude control performance. In this paper, we propose a novel approach to improve the attitude update rate of a star tracker. The electronic Rolling Shutter (RS) imaging mode of the complementary metal-oxide semiconductor (CMOS) image sensor in the star tracker is applied to acquire star images in which the star spots are exposed with row-to-row time offsets, thereby reflecting the rotation of star tracker at different times. The attitude estimation method with a single star spot is developed to realize the multiple attitude updates by a star image, so as to reach a high update rate. The simulation and experiment are performed to verify the proposed approaches. The test results demonstrate that the proposed approach is effective and the attitude update rate of a star tracker is increased significantly.
Application of GPS attitude determination to gravity gradient stabilized spacecraft
NASA Technical Reports Server (NTRS)
Lightsey, E. G.; Cohen, Clark E.; Parkinson, Bradford W.
1993-01-01
Recent advances in the Global Positioning System (GPS) technology have initiated a new era in aerospace navigation and control. GPS receivers have become increasingly compact and affordable, and new developments have made attitude determination using subcentimeter positioning among two or more antennas feasible for real-time applications. GPS-based attitude control systems will become highly portable packages which provide time, navigation, and attitude information of sufficient accuracy for many aerospace needs. A typical spacecraft application of GPS attitude determination is a gravity gradient stabilized satellite in low Earth orbit that employs a GPS receiver and four body mounted patch antennas. The coupled, linearized equations of motion enable complete position and attitude information to be extracted from only two antennas. A discussion of the various error sources for spaceborne GPS attitude measurement systems is included. Attitude determination of better than 0.3 degrees is possible for 1 meter antenna separation. Suggestions are provided to improve the accuracy of the attitude solution.
Huan, Liu; Ai-Xia, Wang; Yuan-Zhen, Li; Ming-Ming, Zhou
2017-02-22
To investigate the status of knowledge, attitude and behavior of schistosomiasis control of rural residents in Wanjiang River region after a flood, so as to provide the reference for targeted health education. The multistage sampling was applied to select the respondents in rural residents in Wanjiang River region, and the self-designed questionnaire was used to investigate the current situation of knowledge, attitude and behavior of schistosomiasis prevention and control of the rural residents. The total awareness rate of knowledge about the prevention and control of schistosomiasis was 47.92%. The age, education, family income, relatives and friends with medical background, and health education significantly influenced the awareness rate ( χ 2 = 12.76, 89.19, 18.19, 50.83 and 92.60 respectively, all P < 0.05). The accuracy rates of attitude and behavior in schistosomiasis control were 62.89% and 52.37% respectively. The awareness rate of knowledge about the prevention and control of schistosomiasis, and the accuracy rates of attitude and behavior in schistosomiasis control of the rural residents in Wanjiang River region are all inefficient, and therefore, the targeted health education should be strengthened to decrease the risk of schistosomiasis transmission.
Large scale static tests of a tilt-nacelle V/STOL propulsion/attitude control system
NASA Technical Reports Server (NTRS)
1978-01-01
The concept of a combined V/STOL propulsion and aircraft attitude control system was subjected to large scale engine tests. The tilt nacelle/attitude control vane package consisted of the T55 powered Hamilton Standard Q-Fan demonstrator. Vane forces, moments, thermal and acoustic characteristics as well as the effects on propulsion system performance were measured under conditions simulating hover in and out of ground effect.
Schröder, Johanna; Berger, Thomas; Meyer, Björn; Lutz, Wolfgang; Späth, Christina; Michel, Pia; Rose, Matthias; Hautzinger, Martin; Hohagen, Fritz; Klein, Jan Philipp; Moritz, Steffen
2018-05-01
Most individuals with depression do not receive adequate treatment. Internet interventions may help to bridge this gap. Research on attitudes toward Internet interventions might facilitate the dissemination of such interventions by identifying factors that help or hinder uptake and implementation, and by clarifying who is likely to benefit. This study examined whether attitudes toward Internet interventions moderate the effects of a depression-focused Internet intervention, and how attitudes change over the course of treatment among those who do or do not benefit. We recruited 1,004 adults with mild-to-moderate depression symptoms and investigated how attitudes toward Internet interventions are associated with the efficacy of the program deprexis, and how attitudes in the intervention group change from pre to post over a 3 months intervention period, compared to a control group (care as usual). This study consists of a subgroup analysis of the randomized controlled EVIDENT trial. Positive initial attitudes toward Internet interventions were associated with greater efficacy (η 2 p = .014) independent of usage time, whereas a negative attitude (perceived lack of personal contact) was associated with reduced efficacy (η 2 p = .012). Users' attitudes changed during the trial, and both the magnitude and direction of attitude change were associated with the efficacy of the program over time (η 2 p = .030). Internet interventions may be the most beneficial for individuals with positive attitudes toward them. Informing potential users about evidence-based Internet interventions might instill positive attitudes and thereby optimize the benefits such interventions can provide. Assessing attitudes prior to treatment might help identify suitable users. © 2018 Wiley Periodicals, Inc.
Crew exploration vehicle (CEV) attitude control using a neural-immunology/memory network
NASA Astrophysics Data System (ADS)
Weng, Liguo; Xia, Min; Wang, Wei; Liu, Qingshan
2015-01-01
This paper addresses the problem of the crew exploration vehicle (CEV) attitude control. CEVs are NASA's next-generation human spaceflight vehicles, and they use reaction control system (RCS) jet engines for attitude adjustment, which calls for control algorithms for firing the small propulsion engines mounted on vehicles. In this work, the resultant CEV dynamics combines both actuation and attitude dynamics. Therefore, it is highly nonlinear and even coupled with significant uncertainties. To cope with this situation, a neural-immunology/memory network is proposed. It is inspired by the human memory and immune systems. The control network does not rely on precise system dynamics information. Furthermore, the overall control scheme has a simple structure and demands much less computation as compared with most existing methods, making it attractive for real-time implementation. The effectiveness of this approach is also verified via simulation.
Attitude and vibration control of a large flexible space-based antenna
NASA Technical Reports Server (NTRS)
Joshi, S. M.
1982-01-01
Control systems synthesis is considered for controlling the rigid body attitude and elastic motion of a large deployable space-based antenna. Two methods for control systems synthesis are considered. The first method utilizes the stability and robustness properties of the controller consisting of torque actuators and collocated attitude and rate sensors. The second method is based on the linear-quadratic-Gaussian control theory. A combination of the two methods, which results in a two level hierarchical control system, is also briefly discussed. The performance of the controllers is analyzed by computing the variances of pointing errors, feed misalignment errors and surface contour errors in the presence of sensor and actuator noise.
NASA Astrophysics Data System (ADS)
Gutwill-Wise, Joshua P.
2001-05-01
This study evaluates new materials, "modules", for teaching introductory chemistry courses. The modules, under development by faculty from two NSF-funded consortia, employ real-world contexts and an interactive class format to foster conceptual understanding, scientific thinking, and improved attitudes toward science. The evaluation studies were conducted at two institutions, a small college and a large university. The experimental design at each school compared students in a course section taught with modules to those in a section that used a textbook and lecture format. At both schools, students in the modular section outperformed the control group on conceptual problems in chemistry and on scientific thinking problems. Modular section students at the large university also outperformed their peers on the first midterm exam in the subsequent organic chemistry course. Regarding attitudes, the modular section students were more positive about chemistry and the course than their peers in the control section at the small college. However, at the large school, the opposite attitudinal pattern was found. An analysis of informal focus group data provides insight into the negative attitudes in the modular section of the large course. Possible remedies for the issues raised are discussed.
International Space Station Attitude Motion Associated With Flywheel Energy Storage
NASA Technical Reports Server (NTRS)
Roithmayr, Carlos M.
1999-01-01
Flywheels can exert torque that alters the Station's attitude motion, either intentionally or unintentionally. A design is presented for a once planned experiment to contribute torque for Station attitude control, while storing or discharging energy. Two contingencies are studied: the abrupt stop of one rotor while another rotor continues to spin at high speed, and energy storage performed with one rotor instead of a counter rotating pair. Finally, the possible advantages to attitude control offered by a system of ninety-six flywheels are discussed.
2001 Flight Mechanics Symposium
NASA Technical Reports Server (NTRS)
Lynch, John P. (Editor)
2001-01-01
This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on June 19-21, 2001. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to attitude/orbit determination, prediction and control; attitude simulation; attitude sensor calibration; theoretical foundation of attitude computation; dynamics model improvements; autonomous navigation; constellation design and formation flying; estimation theory and computational techniques; Earth environment mission analysis and design; and, spacecraft re-entry mission design and operations.