NASA Technical Reports Server (NTRS)
Chamberlin, K.; Clagett, C.; Correll, T.; Gruner, T.; Quinn, T.; Shiflett, L.; Schnurr, R.; Wennersten, M.; Frederick, M.; Fox, S. M.
1993-01-01
The attitude Control Electronics (ACE) Box is the center of the Attitude Control Subsystem (ACS) for the Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX) satellite. This unit is the single point interface for all of the Attitude Control Subsystem (ACS) related sensors and actuators. Commands and telemetry between the SAMPEX flight computer and the ACE Box are routed via a MIL-STD-1773 bus interface, through the use of an 80C85 processor. The ACE Box consists of the flowing electronic elements: power supply, momentum wheel driver, electromagnet driver, coarse sun sensor interface, digital sun sensor interface, magnetometer interface, and satellite computer interface. In addition, the ACE Box also contains an independent Safehold electronics package capable of keeping the satellite pitch axis pointing towards the sun. The ACE Box has dimensions of 24 x 31 x 8 cm, a mass of 4.3 kg, and an average power consumption of 10.5 W. This set of electronics was completely designed, developed, integrated, and tested by personnel at NASA GSFC. SAMPEX was launched on July 3, 1992, and the initial attitude acquisition was successfully accomplished via the analog Safehold electronics in the ACE Box. This acquisition scenario removed the excess body rates via magnetic control and precessed the satellite pitch axis to within 10 deg of the sun line. The performance of the SAMPEX ACS in general and the ACE Box in particular has been quite satisfactory.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-12
...) associated with the Electronic Flight Control System that limits pitch and roll attitude functions. The... substantiate the pitch and roll attitude limiting functions and the appropriateness of the chosen limits. Type... attitudes greater than +30 degrees and less than -15 degrees, and roll angles greater than plus or minus 67...
Fault tolerant programmable digital attitude control electronics study
NASA Technical Reports Server (NTRS)
Sorensen, A. A.
1974-01-01
The attitude control electronics mechanization study to develop a fault tolerant autonomous concept for a three axis system is reported. Programmable digital electronics are compared to general purpose digital computers. The requirements, constraints, and tradeoffs are discussed. It is concluded that: (1) general fault tolerance can be achieved relatively economically, (2) recovery times of less than one second can be obtained, (3) the number of faulty behavior patterns must be limited, and (4) adjoined processes are the best indicators of faulty operation.
NASA Technical Reports Server (NTRS)
Peacock, W. M.
1973-01-01
The National Aeronautics and Space Administration (NASA), launched ITOS-D with an improved attitude control system. A Hall generator brushless dc torque motor replaced the brush dc torque motor on Tiros-M and ITOS-A. Two CO2 attitude horizon sensors and one mirror replaced the four wideband horizon sensors and two mirrors on ITOS-1 and NOAA-1. Redundant pitch-control electronic boxes containing additional electronic circuitry for earth-splitting and brushless motor electronics were used. A method of generating a spacecraft earth-facing side reference for comparison to the time occurrence of the earth-splitting pulse was used to automatically correct pitch-attitude error. A single rotating flywheel, supported by a single bearing, provided gyroscopic stability and the required momentum interchange to keep one side of the satellite facing the earth. Magnetic torquing against the earth's magnetic field eliminated the requirement for expendable propellants which would limit satellite life in orbit.
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-20
... flight characteristics associated with fixed attitude limits. Embraer S.A. will implement pitch and roll attitude protection functions through the normal modes of the electronic flight control system that will... pitch attitudes necessary for emergency maneuvering or roll angles up to 66 degrees with flaps up, or 60...
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.
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.
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.
NASA Astrophysics Data System (ADS)
Xu, Xing; Zhou, Kongkang; Zou, Nannan; Jiang, Hong; Cui, Xiaoli
2015-09-01
The current research of air suspension mainly focuses on the characteristics and design of the air spring. In fact, electronically controlled air suspension (ECAS) has excellent performance in flexible height adjustment during different driving conditions. However, the nonlinearity of the ride height adjusting system and the uneven distribution of payload affect the control accuracy of ride height and the body attitude. Firstly, the three-point measurement system of three height sensors is used to establish the mathematical model of the ride height adjusting system. The decentralized control of ride height and the centralized control of body attitude are presented to design the ride height control system for ECAS. The exact feedback linearization method is adopted for the nonlinear mathematical model of the ride height system. Secondly, according to the hierarchical control theory, the variable structure control (VSC) technique is used to design a controller that is able to adjust the ride height for the quarter-vehicle anywhere, and each quarter-vehicle height control system is independent. Meanwhile, the three-point height signals obtained by three height sensors are tracked to calculate the body pitch and roll attitude over time, and then by calculating the deviation of pitch and roll and its rates, the height control correction is reassigned based on the fuzzy algorithm. Finally, to verify the effectiveness and performance of the proposed combined control strategy, a validating test of ride height control system with and without road disturbance is carried out. Testing results show that the height adjusting time of both lifting and lowering is over 5 s, and the pitch angle and the roll angle of body attitude are less than 0.15°. This research proposes a hierarchical control method that can guarantee the attitude stability, as well as satisfy the ride height tracking system.
Design of a Solar Sail Mission to Mars
NASA Technical Reports Server (NTRS)
Eastridge, Richard; Funston, Kerry; Okia, Aminat; Waldrop, Joan; Zimmerman, Christopher
1989-01-01
An evaluation of the design of the solar sail includes key areas such as structures, sail deployment, space environmental effects, materials, power systems, telemetry, communications, attitude control, thermal control, and trajectory analysis. Deployment and material constraints determine the basic structure of the sail, while the trajectory of the sail influences the choice of telemetry, communications, and attitude control systems. The thermal control system of the sail for the structures and electronics takes into account the effects of the space environment. Included also are a cost and weight estimate for the sail.
Integrated Power and Attitude Control System (IPACS) technology developments
NASA Technical Reports Server (NTRS)
Eisenhaure, David B.; Bechtel, Robert; Hockney, Richard; Oglevie, Ron; Olszewski, Mitch
1990-01-01
Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of storing electrical energy in flywheels and utilizing the resulting angular momentum for spacecraft attitude control. Such a system has been shown to have numerous attractive features relative to more contemporary technology, and is appropriate to many applications (including high-performance slewing actuators). Technology advances over the last two decades in composite rotors, motor/generator/electronics, and magnetic bearings are found to support the use of IPACS for increasingly sophisticated applications. It is concluded that the concept offers potential performance advantages as well as savings in mass and life-cycle cost. Viewgraphs and discussion on IPACS are included.
Advanced Integrated Power and Attitude Control System (IPACS) study
NASA Technical Reports Server (NTRS)
Oglevie, R. E.; Eisenhaure, D. B.
1985-01-01
Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission.
Integrated Power and Attitude Control Systems for Space Station
NASA Technical Reports Server (NTRS)
Oglevie, R. E.; Eisenhaure, D. B.
1985-01-01
Integrated Power and Attitude Control Systems (IPACS) studies performed over a decade ago established the feasibility of simultaneously storing electrical energy in wheels and utilizing the resulting momentum for spacecraft attitude control. It was shown that such a system possessed many advantages over other contemporary energy storage and attitude control systems in many applications. More recent technology advances in composite rotors, magnetic bearings, and power control electronics have triggered new optimism regarding the feasibility and merits of such a system. The paper presents the results of a recent study whose focus was to define an advanced IPACS and to evaluate its merits for the Space Station application. A system and component design concept is developed to establish the system performance capability. A system level trade study, including life-cycle costing, is performed to define the merits of the system relative to two other candidate systems. It is concluded that an advanced IPACS concept is not only feasible, but offers substantial savings in mass, and life-cycle cost.
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.
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.
Mariner Mars 1971 attitude control subsystem
NASA Technical Reports Server (NTRS)
Edmunds, R. S.
1974-01-01
The Mariner Mars 1971 attitude control subsystem (ACS) is discussed. It is comprised of a sun sensor set, a Canopus tracker, an inertial reference unit, two cold gas reaction control assemblies, two rocket engine gimbal actuators, and an attitude control electronics unit. The subsystem has the following eight operating modes: (1) launch, (2) sun acquisition, (3) roll search, (4) celestial cruise, (5) all-axes inertial, (6) roll inertial, (7) commanded turn, and (8) thrust vector control. In the celestial cruise mode, the position control is held to plus or minus 0.25 deg. Commanded turn rates are plus or minus 0.18 deg/s. The attitude control logic in conjunction with command inputs from other spacecraft subsystems establishes the ACS operating mode. The logic utilizes Sun and Canopus acquisition signals generated within the ACS to perform automatic mode switching so that dependence of ground control is minimized when operating in the sun acquisition, roll search, and celestial cruise modes. The total ACS weight is 65.7 lb, and includes 5.4 lb of nitrogen gas. Total power requirements vary from 9 W for the celestial cruise mode to 54 W for the commanded turn mode.
Apollo Guidance, Navigation, and Control (GNC) Hardware Overview
NASA Technical Reports Server (NTRS)
Interbartolo, Michael
2009-01-01
This viewgraph presentation reviews basic guidance, navigation and control (GNC) concepts, examines the Command and Service Module (CSM) and Lunar Module (LM) GNC organization and discusses the primary GNC and the CSM Stabilization and Control System (SCS), as well as other CSM-specific hardware. The LM Abort Guidance System (AGS), Control Electronics System (CES) and other LM-specific hardware are also addressed. Three subsystems exist on each vehicle: the computer subsystem (CSS), the inertial subsystem (ISS) and the optical subsystem (OSS). The CSS and ISS are almost identical between CSM and LM and each is designed to operate independently. CSM SCS hardware are highlighted, including translation control, rotation controls, gyro assemblies, a gyro display coupler and flight director attitude indicators. The LM AGS hardware are also highlighted and include the abort electronics assembly and the abort sensor assembly; while the LM CES hardware includes the attitude controller assembly, thrust/translation controller assemblies and the ascent engine arming assemble. Other common hardware including the Orbital Rate Display - Earth and Lunar (ORDEAL) and the Crewman Optical Alignment Sight (COAS), a docking aid, are also highlighted.
Wheel configurations for combined energy storage and attitude control systems
NASA Technical Reports Server (NTRS)
Oglevie, R. E.
1985-01-01
Integrated power and attitude control system (IPACS) studies performed over a decade ago established the feasibility of simultaneously storing electrical energy in wheels and utilizing the resulting momentum for spacecraft attitude control. It was shown that such a system possessed many advantages over other contemporary energy storage and attitude control systems in many applications. More recent technology advances in composite rotors, magnetic bearings, and power control electronics have triggered new optimism regarding the feasibility and merits of such a system. This paper presents the results of a recent study whose focus was to define an advanced IPACS and to evaluate its merits for the Space Station application. Emphasis is given to the selection of the wheel configuration to perform the combined functions. A component design concept is developed to establish the system performance capability. A system-level trade study, including life-cycle costing, is performed to define the merits of the system relative to two other candidate systems. It is concluded that an advanced IPACS concept is not only feasible but offers substantial savings in mass and life-cycle cost.
NASA Technical Reports Server (NTRS)
Phenneger, M. C.; Singhal, S. P.; Lee, T. H.; Stengle, T. H.
1985-01-01
The work performed by the Attitude Determination and Control Section at the National Aeronautics and Space Administration/Goddard Space Flight Center in analyzing and evaluating the performance of infrared horizon sensors is presented. The results of studies performed during the 1960s are reviewed; several models for generating the Earth's infrared radiance profiles are presented; and the Horizon Radiance Modeling Utility, the software used to model the horizon sensor optics and electronics processing to computer radiance-dependent attitude errors, is briefly discussed. Also provided is mission experience from 12 spaceflight missions spanning the period from 1973 to 1984 and using a variety of horizon sensing hardware. Recommendations are presented for future directions for the infrared horizon sensing technology.
Armani, R; Mitchell, L E; Allen-Graham, J; Heriot, N R; Kotsimbos, T; Wilson, J W
2016-06-01
The current health system in Australia is comprised of both electronic- and paper-based medical records. The Federal Government has approved funding for the development of an individual health identifier and a universally adopted online health repository. To determine attitudes and beliefs of patients and healthcare workers regarding the use of stored medical information and the personally controlled electronic health record (PCEHR) in selected major hospitals in Victoria. Qualitative survey of patients and healthcare workers (n = 600 each group) conducted during 2014 across five major hospitals in Melbourne to measure the awareness, attitudes and barriers to electronic health and the PCEHR. Of the patients, 93.3% support the concept of a shared electronic healthcare record, 33.7% were aware of the PCEHR and only 11% had registered. The majority of healthcare workers believed that the presence of a shared health record would result in an increased appropriateness of care and patient safety by reducing adverse drug events and improving the timeliness of care provided. However, only 46% of healthcare workers were aware of the PCEHR. This study provides a baseline evaluation of perceptions surrounding eHealth and PCHER in acute health services in five metropolitan centres. While there appears to be a readiness for adoption of these strategies for healthcare documentation, patients require motivation to register for the PCEHR, and healthcare workers require more information on the potential benefits to them to achieve more timely and efficient care. © 2016 Royal Australasian College of Physicians.
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.
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.
Cassini at Saturn Proximal Orbits - Attitude Control Challenges
NASA Technical Reports Server (NTRS)
Burk, Thomas A.
2013-01-01
The Cassini mission at Saturn will come to an end in the spring and summer of 2017 with a series of 22 orbits that will dip inside the rings of Saturn. These are called proximal orbits and will conclude with spacecraft disposal into the atmosphere of the ringed world on September 15, 2017. These unique orbits that cross the ring plane only a few thousand kilometers above the cloud tops of the planet present new attitude control challenges for the Cassini operations team. Crossing the ring plane so close to the inner edge of the rings means that the Cassini orientation during the crossing will be tailored to protect the sensitive electronics bus of the spacecraft. This orientation will put the sun sensors at some extra risk so this paper discusses how the team prepares for dust hazards. Periapsis is so close to the planet that spacecraft controllability with RCS thrusters needs to be evaluated because of the predicted atmospheric torque near closest approach to Saturn. Radiation during the ring plane crossings will likely trigger single event transients in some attitude control sensors. This paper discusses how the attitude control team deals with radiation hazards. The angular size and unique geometry of the rings and Saturn near periapsis means that star identification will be interrupted and this paper discusses how the safe mode attitude is selected to best deal with these large bright bodies during the proximal orbits.
NASA Technical Reports Server (NTRS)
Stephenson, R. Rhoads
1985-01-01
The Galileo mission and spacecraft, consisting of a Jupiter-orbiter and an atmospheric entry probe, are discussed. Components will include: magnetometers and plasma-wave antennas on a boom, high-gain antenna, probe vehicle, two different bus electronics packages, and a radioisotope thermoelectric generator. Instruments, investigators and objectives are tabulated for both probe science and orbiter science investigations. Requirements in the design of the attitude and articulation control system are very stringent because of the complex dynamics, flexible body effects, the need for autonomy, and the severe radiation environment in the Jupiter nighborhood. Galileo was intended to be ready for launch via Space Shuttle in May of 1986.
Comparative study of MYSat attitude stability effect on power generation and lifetime
NASA Astrophysics Data System (ADS)
Amilia Ismail, Norilmi; Thaheer, Ahmad Shaqeer Mohamed; Izmir Yamin, Mohd.
2018-05-01
Universiti Sains Malaysia Space System Lab (USSL) is currently developing a 1U cubesat named MYSat. The satellite mission is to measure electron-density in the Ionosphere E-Layer. Power generation from a solar panel is limited due to a small area of the satellite. Apart from that, the satellite is expecting to continuously spinning and tumbling throughout the mission lifetime as the satellite will be launched without an attitude control system. This paper compares the effect on power generation and the lifetime of MYSat of two conditions; first is with attitude controll where satellite pointing to nadir and later is uncontrol attitude of the satellite. The analysis has been conducted using Analytical Graphics, Inc. (AGI) Systems Tool Kit (STK) software. This study assumed the satellite used a hexagonal solar cell with a theoretical efficiency of 29% identical to an Ultra Triple-Junction (UTJ) solar cell. The simulation is done in one year duration on different attitude configuration. The worst-case condition, where the Earth is positioned at apogee, has been chosen for the comparative study and the lifetime of the satellite is also simulated and compared.
Educational games in geriatric medicine education: a systematic review
2010-01-01
Objective To systematically review the medical literature to assess the effect of geriatric educational games on the satisfaction, knowledge, beliefs, attitudes and behaviors of health care professionals. Methods We conducted a systematic review following the Cochrane Collaboration methodology including an electronic search of 10 electronic databases. We included randomized controlled trials (RCT) and controlled clinical trials (CCT) and excluded single arm studies. Population of interests included members (practitioners or students) of the health care professions. Outcomes of interests were participants' satisfaction, knowledge, beliefs, attitude, and behaviors. Results We included 8 studies evaluating 5 geriatric role playing games, all conducted in United States. All studies suffered from one or more methodological limitations but the overall quality of evidence was acceptable. None of the studies assessed the effects of the games on beliefs or behaviors. None of the 8 studies reported a statistically significant difference between the 2 groups in terms of change in attitude. One study assessed the impact on knowledge and found non-statistically significant difference between the 2 groups. Two studies found levels of satisfaction among participants to be high. We did not conduct a planned meta-analysis because the included studies either reported no statistical data or reported different summary statistics. Conclusion The available evidence does not support the use of role playing interventions in geriatric medical education with the aim of improving the attitudes towards the elderly. PMID:20416055
ERIC Educational Resources Information Center
Nickles, Kenneth Patrick
2012-01-01
The impact of electronic health records on healthcare professional's beliefs and attitudes toward face to face communication during patient and provider interactions was examined. Quantitative survey research assessed user attitudes towards an electronic health record system and revealed that healthcare professionals from a wide range of…
NASA Technical Reports Server (NTRS)
Steinmetz, G. G.
1986-01-01
The development of an electronic primary flight display format aligned with the aircraft velocity vector, a simulation evaluation comparing this format with an electronic attitude-aligned primary flight display format, and a flight evaluation of the velocity-vector-aligned display format are described. Earlier tests in turbulent conditions with the electronic attitude-aligned display format had exhibited unsteadiness. A primary objective of aligning the display format with the velocity vector was to take advantage of a velocity-vector control-wheel steering system to provide steadiness of display during turbulent conditions. Better situational awareness under crosswind conditions was also achieved. The evaluation task was a curved, descending approach with turbulent and crosswind conditions. Primary flight display formats contained computer-drawn perspective runway images and flight-path angle information. The flight tests were conducted aboard the NASA Transport Systems Research Vehicle (TSRV). Comparative results of the simulation and flight tests were principally obtained from subjective commentary. Overall, the pilots preferred the display format aligned with the velocity vector.
NASA Astrophysics Data System (ADS)
Mathew, Nishi Mary
Preservice elementary teachers' science teaching efficacy and attitude towards science teaching are important determinants of whether and how they will teach science in their classrooms. Preservice teachers' understanding of science and science teaching experiences have an impact on their beliefs about their ability to teach science. This study had a quasi-experimental pretest-posttest control group design (N = 60). Preservice elementary teachers in this study were networked through the Internet (using e-mail, newsgroups, listserv, world wide web access and electronic mentoring) during their science methods class and student practicum. Electronic networking provides a social context in which to learn collaboratively, share and reflect upon science teaching experiences and practices, conduct tele-research effectively, and to meet the demands of student teaching through peer support. It was hoped that the activities over the electronic networks would provide them with positive and helpful science learning and teaching experiences. Self-efficacy was measured using a 23-item Likert scale instrument, the Science Teaching Efficacy Belief Instrument, Form-B (STEBI-B). Attitude towards science teaching was measured using the Revised Science Attitude Scale (RSAS). Analysis of covariance was used to analyze the data, with pretest scores as the covariate. Findings of this study revealed that prospective elementary teachers in the electronically networked group had better science teaching efficacy and personal science teaching efficacy as compared to the non-networked group of preservice elementary teachers. The science teaching outcome expectancy of prospective elementary teachers in the networked group was not greater than that of the prospective teachers in the non-networked group (at p < 0.05). Attitude towards science teaching was not significantly affected by networking. However, this is surmised to be related to the duration of the study. Information about the experiences of the participants in this study was also collected through interview, and inventories. Findings from the interview data revealed that prospective teachers benefited from the interactions with peers, science mentors, and science methods instructors during student teaching. Students who did not have access to computers noted that time was a constraint in the use of the electronic networks.
Visual attitude propagation for small satellites
NASA Astrophysics Data System (ADS)
Rawashdeh, Samir A.
As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation. The problem of visual attitude propagation as a small satellite attitude determination system is addressed from several aspects: related work, algorithm design, hardware and performance evaluation, possible applications, and on-orbit experimentation. These areas of consideration reflect the organization of this dissertation. A "stellar gyroscope" is developed, which is a visual star-based attitude propagator that uses relative motion of stars in an imager's field of view to infer the attitude changes. The device generates spacecraft relative attitude estimates in three degrees of freedom. Algorithms to perform the star detection, correspondence, and attitude propagation are presented. The Random Sample Consensus (RANSAC) approach is applied to the correspondence problem to successfully pair stars across frames while mitigating falsepositive and false-negative star detections. This approach provides tolerance to the noise levels expected in using miniature optics and no baffling, and the noise caused by radiation dose on orbit. The hardware design and algorithms are validated using test images of the night sky. The application of the stellar gyroscope as part of a CubeSat attitude determination and control system is described. The stellar gyroscope is used to augment a MEMS gyroscope attitude propagation algorithm to minimize drift in the absence of an absolute attitude sensor. The stellar gyroscope is a technology demonstration experiment on KySat-2, a 1-Unit CubeSat being developed in Kentucky that is in line to launch with the NASA ELaNa CubeSat Launch Initiative. It has also been adopted by industry as a sensor for CubeSat Attitude Determination and Control Systems (ADCS). KEYWORDS: Small Satellites, Attitude Determination, Egomotion Estimation, RANSAC, Image Processing.
14 CFR 23.1311 - Electronic display instrument systems.
Code of Federal Regulations, 2010 CFR
2010-01-01
... Continued Airworthiness required by § 23.1529. (3) Not inhibit the primary display of attitude, airspeed... indicator, and attitude instrument or individual electronic display indicators for the altitude, airspeed, and attitude that are independent from the airplane's primary electrical power system. These secondary...
ERIC Educational Resources Information Center
Wanchid, Raveewan; Charoensuk, Valaikorn
2015-01-01
The purposes of this study were to investigate the effects of the use of paper-based and weblog-based electronic portfolios on the writing achievement of limited English proficiency students, to survey the students' attitudes towards the use of the portfolio assessment, and to compare the viewpoints of the students in the control and experimental…
Evaluation of STOL navigation avionics
NASA Technical Reports Server (NTRS)
Dunn, W. R., Jr.
1977-01-01
Research projects, including work on a vector magnetometer for aircraft attitude measurement, are summarized. The earth's electric field phenomena was investigated in its application to aircraft control and navigation. Research on electronic aircraft cabin noise suppression is reviewed and strapdown inertial reference unit technical support is outlined.
76 FR 64813 - Electronic Prescriptions for Controlled Substances Clarification
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-19
... employees' laptop computers and employee's mobile devices.\\9\\ Numerous recent news articles describe...,'' Office of Applied Studies, 2010 (NSDUH Series H-38A, HHS Publication No. SMA 10-4856), http://www.oas..., ``2009 Parents and Teens Attitude Tracking Study Report'' March 2, 2010. Increased Security Breaches...
Albarracin, Dolores; Romer, Daniel; Jones, Christopher; Hall Jamieson, Kathleen; Jamieson, Patrick
2018-06-29
Recent content analyses of YouTube postings reveal a proliferation of user generated videos with misleading statements about the health consequences of various types of nontraditional tobacco use (eg, electronic cigarettes; e-cigarettes). This research was aimed at obtaining evidence about the potential effects of YouTube postings about tobacco products on viewers' attitudes toward these products. A sample of young adults recruited online (N=350) viewed one of four highly viewed YouTube videos containing misleading health statements about chewing tobacco, e-cigarettes, hookahs, and pipe smoking, as well as a control YouTube video unrelated to tobacco products. The videos about e-cigarettes and hookahs led to more positive attitudes toward the featured products than did control videos. However, these effects did not fully translate into attitudes toward combustive cigarette smoking, although the pipe video led to more positive attitudes toward combustive smoking than did the chewing and the hookah videos, and the e-cigarette video led to more positive attitudes toward combustive cigarette smoking than did the chewing video. This research revealed young people's reactions to misleading claims about tobacco products featured in popular YouTube videos. Policy implications are discussed. ©Dolores Albarracin, Daniel Romer, Christopher Jones, Kathleen Hall Jamieson, Patrick Jamieson. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 29.06.2018.
Shabani, Mahsa; Bezuidenhout, Louise; Borry, Pascal
2014-11-01
Introducing data sharing practices into the genomic research arena has challenged the current mechanisms established to protect rights of individuals and triggered policy considerations. To inform such policy deliberations, soliciting public and research participants' attitudes with respect to genomic data sharing is a necessity. The main electronic databases were searched in order to retrieve empirical studies, investigating the attitudes of research participants and the public towards genomic data sharing through public databases. In the 15 included studies, participants' attitudes towards genomic data sharing revealed the influence of a constellation of interrelated factors, including the personal perceptions of controllability and sensitivity of data, potential risks and benefits of data sharing at individual and social level and also governance level considerations. This analysis indicates that future policy responses and recruitment practices should be attentive to a wide variety of concerns in order to promote both responsible and progressive research.
NASA Technical Reports Server (NTRS)
Peacock, W. M.
1971-01-01
The ITOS with an improved attitude control system is described. A Hall generator brushless dc torque motor will replace the brush dc torque motor on ITOS-I and ITOS-A (NOAA-1). The four attitude horizon sensors will be replaced with two CO2 sensors for better horizon definition. An earth horizon splitting technique will be used to keep the earth facing side of the satellite toward earth even if the desired circular orbit is not achieved. The external appearance of the pitch control subsystem differs from TIROS-M (ITOS-1) and ITOS-A (NOAA-1) in that two instead of one pitch control electronics (PCE) boxes are used. Two instead of four horizon sensors will be used and one instead of two mirrors will be used for sensor scanning. The brushless motor will eliminate the requirement for brushes, strain gages and the telemetry for the brush wear. A single rotating flywheel, supported by a single bearing provides the gyroscopic stability and the required momentum interchange to keep one side of the satellite facing the earth. Magnetic torquing against the earth's magnetic field eliminates the requirement for expendable propellants which would limit satellite life in orbit.
TRMM On Orbit Attitude Control System Performance
NASA Technical Reports Server (NTRS)
Robertson, Brent; Placanica, Sam; Morgenstern, Wendy
1999-01-01
This paper presents an overview of the Tropical Rainfall Measuring Mission (TRMM) Attitude Control System (ACS) along with detailed in-flight performance results for each operational mode. The TRMM spacecraft is an Earth-pointed, zero momentum bias satellite launched on November 27, 1997 from Tanegashima Space Center, Japan. TRMM is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan designed to monitor and study tropical rainfall and the associated release of energy. Launched to provide a validation for poorly known rainfall data sets generated by global climate models, TRMM has demonstrated its utility by reducing uncertainties in global rainfall measurements by a factor of two. The ACS is comprised of Attitude Control Electronics (ACE), an Earth Sensor Assembly (ESA), Digital Sun Sensors (DSS), Inertial Reference Units (IRU), Three Axis Magnetometers (TAM), Coarse Sun Sensors (CSS), Magnetic Torquer Bars (MTB), Reaction Wheel Assemblies (RWA), Engine Valve Drivers (EVD) and thrusters. While in Mission Mode, the ESA provides roll and pitch axis attitude error measurements and the DSS provide yaw updates twice per orbit. In addition, the TAM in combination with the IRU and DSS can be used to provide pointing in a contingency attitude determination mode which does not rely on the ESA. Although the ACS performance to date has been highly successful, lessons were learned during checkout and initial on-orbit operation. This paper describes the design, on-orbit checkout, performance and lessons learned for the TRMM ACS.
Electronics design of the airborne stabilized platform attitude acquisition module
NASA Astrophysics Data System (ADS)
Xu, Jiang; Wei, Guiling; Cheng, Yong; Li, Baolin; Bu, Hongyi; Wang, Hao; Zhang, Zhanwei; Li, Xingni
2014-02-01
We present an attitude acquisition module electronics design for the airborne stabilized platform. The design scheme, which is based on Integrated MEMS sensor ADIS16405, develops the attitude information processing algorithms and the hardware circuit. The hardware circuits with a small volume of only 44.9 x 43.6 x 24.6 mm3, has the characteristics of lightweight, modularization and digitalization. The interface design of the PC software uses the combination plane chart with track line to receive the attitude information and display. Attitude calculation uses the Kalman filtering algorithm to improve the measurement accuracy of the module in the dynamic environment.
High-precision buffer circuit for suppression of regenerative oscillation
NASA Technical Reports Server (NTRS)
Tripp, John S.; Hare, David A.; Tcheng, Ping
1995-01-01
Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, stable, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative oscillation and consequent rectification bias errors. Oscillation suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior oscillation suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative oscillation occurring when typical shielded cable loads are driven.
Teen use of a patient portal: a qualitative study of parent and teen attitudes.
Bergman, David A; Brown, Nancy L; Wilson, Sandra
2008-01-01
We conducted a qualitative study of the attitudes of teens and parents toward the use of a patient portal. We conducted two teen and two parent focus groups, one teen electronic bulletin board, and one parent electronic bulletin board. Videotapes and transcripts from the groups were independently analyzed by two reviewers for significant themes, which were then validated by two other members of the research team. Twenty-eight teens and 23 parents participated in the groups. Significant themes included issues about teens' control of their own healthcare; enthusiasm about the use of a patient portal to access their providers, seek health information, and make appointments; and concerns about confidentiality. In summary, there was considerable support among teens and parents for a patient portal as well as concerns about confidentiality. The teen portal affords an opportunity to negotiate issues of confidentiality.
PhoneSat - The Smartphone Nanosatellite
NASA Technical Reports Server (NTRS)
Westley, Deborah; Yost, Bruce; Petro, Andrew
2013-01-01
PhoneSat 2.4, carried into space on November 19, 2013 aboard a Minotaur I rocket from the Mid-Atlantic Regional Spaceport at NASAs Wallops Flight Facility in Virginia, is the first of the PhoneSat family to use a two-way S-band radio to allow engineers to command the satellite from Earth. This mission also serves as a technology demonstration for a novel attitude determination and control system (ADCS) that establishes and stabilizes the satellites attitude relative to Earth. Unlike the earlier PhoneSats that used a Nexus One, PhoneSat 2.4 uses the Nexus S smartphone, which runs Googles Android operating system, and is made by Samsung Electronics Co., Suwon, So. Korea. The smartphone provides many of the functions needed by the satellite such as a central computer, data memory, ready-made interfaces for communications, navigation and power all pre-assembled in a rugged electronics package.
The MGS Avionics System Architecture: Exploring the Limits of Inheritance
NASA Technical Reports Server (NTRS)
Bunker, R.
1994-01-01
Mars Global Surveyor (MGS) avionics system architecture comprises much of the electronics on board the spacecraft: electrical power, attitude and articulation control, command and data handling, telecommunications, and flight software. Schedule and cost constraints dictated a mix of new and inherited designs, especially hardware upgrades based on findings of the Mars Observer failure review boards.
Perioperative nurses' attitudes toward the electronic health record.
Yontz, Laura S; Zinn, Jennifer L; Schumacher, Edward J
2015-02-01
The adoption of an electronic health record (EHR) is mandated under current health care legislation reform. The EHR provides data that are patient centered and improves patient safety. There are limited data; however, regarding the attitudes of perioperative nurses toward the use of the EHR. The purpose of this project was to identify perioperative nurses' attitudes toward the use of the EHR. Quantitative descriptive survey was used to determine attitudes toward the electronic health record. Perioperative nurses in a southeastern health system completed an online survey to determine their attitudes toward the EHR in providing patient care. Overall, respondents felt the EHR was beneficial, did not add to the workload, improved documentation, and would not eliminate any nursing jobs. Nursing acceptance and the utilization of the EHR are necessary for the successful integration of an EHR and to support the goal of patient-centered care. Identification of attitudes and potential barriers of perioperative nurses in using the EHR will improve patient safety, communication, reduce costs, and empower those who implement an EHR. Copyright © 2015 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.
The mediating role of facebook fan pages.
Chih, Wen-Hai; Hsu, Li-Chun; Wang, Kai-Yu; Lin, Kuan-Yu
2014-01-01
Using the dual mediation hypothesis, this study investigates the role of interestingness (the power of attracting or holding one's attention) attitude towards the news, in the formation of Facebook Fan Page users' electronic word-of-mouth intentions. A total of 599 Facebook fan page users in Taiwan were recruited and structural equation modeling (SEM) was used to test the research hypotheses. The results show that both perceived news entertainment and informativeness positively influence interestingness attitude towards the news. Interestingness attitude towards the news subsequently influences hedonism and utilitarianism attitudes towards the Fan Page, which then influence eWOM intentions. Interestingness attitude towards the news plays a more important role than hedonism and utilitarianism attitudes in generating electronic word-of-mouth intentions. Based on the findings, the implications and future research suggestions are provided.
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
Space Weather Influence on Relative Motion Control using the Touchless Electrostatic Tractor
NASA Astrophysics Data System (ADS)
Hogan, Erik A.; Schaub, Hanspeter
2016-09-01
With recent interest in the use of electrostatic forces for contactless tugging and attitude control of noncooperative objects for orbital servicing and active debris mitigation, the need for a method of remote charge control arises. In this paper, the use of a directed electron beam for remote charge control is considered in conjunction with the relative motion control. A tug vehicle emits an electron beam onto a deputy object, charging it negatively. At the same time, the tug is charged positively due to beam emission, resulting in an attractive electrostatic force. The relative position feedback control between the tug and the passive debris object is studied subject to the charging being created through an electron beam. Employing the nominal variations of the GEO space weather conditions across longitude slots, two electrostatic tugging strategies are considered. First, the electron beam current is adjusted throughout the orbit in order to maximize this resulting electrostatic force. This open-loop control strategy compensates for changes in the nominally expected local space weather environment in the GEO region to adjust for fluctuations in the local plasma return currents. Second, the performance impact of using a fixed electron beam current on the electrostatic tractor is studied if the same natural space weather variations are assumed. The fixed electron beam current shows a minor performance penalty (<5 %) while providing a much simpler implementation that does not require any knowledge of local space weather conditions.
Three axis pulsed plasma thruster with angled cathode and anode strip lines
NASA Technical Reports Server (NTRS)
Cassady, R. Joseph (Inventor); Myers, Roger M. (Inventor); Osborne, Robert D. (Inventor)
2001-01-01
A spacecraft attitude and altitude control system utilizes sets of three pulsed plasma thrusters connected to a single controller. The single controller controls the operation of each thruster in the set. The control of a set of three thrusters in the set makes it possible to provide a component of thrust along any one of three desired axes. This configuration reduces the total weight of a spacecraft since only one controller and its associated electronics is required for each set of thrusters rather than a controller for each thruster. The thrusters are positioned about the spacecraft such that the effect of the thrusters is balanced.
Comparison of consumers’ views on electronic data sharing for healthcare and research
Joseph, Jill G; Ohno-Machado, Lucila
2015-01-01
New models of healthcare delivery such as accountable care organizations and patient-centered medical homes seek to improve quality, access, and cost. They rely on a robust, secure technology infrastructure provided by health information exchanges (HIEs) and distributed research networks and the willingness of patients to share their data. There are few large, in-depth studies of US consumers’ views on privacy, security, and consent in electronic data sharing for healthcare and research together. Objective This paper addresses this gap, reporting on a survey which asks about California consumers’ views of data sharing for healthcare and research together. Materials and Methods The survey conducted was a representative, random-digit dial telephone survey of 800 Californians, performed in Spanish and English. Results There is a great deal of concern that HIEs will worsen privacy (40.3%) and security (42.5%). Consumers are in favor of electronic data sharing but elements of transparency are important: individual control, who has access, and the purpose for use of data. Respondents were more likely to agree to share deidentified information for research than to share identified information for healthcare (76.2% vs 57.3%, p < .001). Discussion While consumers show willingness to share health information electronically, they value individual control and privacy. Responsiveness to these needs, rather than mere reliance on Health Insurance Portability and Accountability Act (HIPAA), may improve support of data networks. Conclusion Responsiveness to the public’s concerns regarding their health information is a pre-requisite for patient-centeredness. This is one of the first in-depth studies of attitudes about electronic data sharing that compares attitudes of the same individual towards healthcare and research. PMID:25829461
Trust and Privacy in Healthcare
NASA Astrophysics Data System (ADS)
Singleton, Peter; Kalra, Dipak
This paper considers issues of trust and privacy in healthcare around increased data-sharing through Electronic Health Records (EHRs). It uses a model structured around different aspects of trust in the healthcare organisation’s reasons for greater data-sharing and their ability to execute EHR projects, particularly any associated confidentiality controls. It reflects the individual’s personal circumstances and attitude to use of health records.
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.
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
2001-01-03
KENNEDY SPACE CENTER, Fla. -- Under wispy white morning clouds, Space Shuttle Atlantis nears the Rotating Service Structure on Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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
The Effects of Propellant Slosh Dynamics on the Solar Dynamics Observatory
NASA Technical Reports Server (NTRS)
Mason, Paul; Starin, Scott R.
2011-01-01
The Solar Dynamics Observatory (SDO) mission, which is part of the Living With a Star program, was successfully launched and deployed from its Atlas V launch vehicle on February 11, 2010. SDO is an Explorer-class mission now operating in a geosynchronous orbit (GEO). The basic mission is to observe the Sun for a very high percentage of the 5-year mission (10-year goal) with long stretches of uninterrupted observations and with constant, high-data-rate transmission to a dedicated ground station located in White Sands, New Mexico. A significant portion of SDO's launch mass was propellant, contained in two large tanks. To ensure performance with this level of propellant, a slosh analysis was performed. This paper provides an overview of the SDO slosh analysis, the on-orbit experience, and the lessons learned. SDO is a three-axis controlled, single fault tolerant spacecraft. The attitude sensor complement includes sixteen coarse Sun sensors, a digital Sun sensor, three two-axis inertial reference units, two star trackers, and four guide telescopes. Attitude actuation is performed either using four reaction wheels or eight thrusters, depending on the control mode, along with single main engine which nominally provides velocity-change thrust. The attitude control software has five nominal control modes: three wheel-based modes and two thruster-based modes. A wheel-based Safehold running in the Attitude Control Electronics (ACE) 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. To achieve and maintain a geosynchronous orbit for a 2974-kilogram spacecraft in a cost effective manner, the SDO team designed a high-efficiency propulsive system. This bi-propellant design includes a 100-pound-force main engine and eight 5-pound-force attitude control thrusters. The main engine provides high specific impulse for the maneuvers to attain GEO, while the smaller Attitude Control System (ACS) thrusters manage the disturbance torques of the larger main engine and provide the capability for much smaller orbit adjustment burns. SDO's large solar profile produces a large solar torque disturbance and momentum buildup. This buildup drives the frequency of momentum unloads via ACS thrusters. SDO requires 1409 kilograms (which is approximately half the launch mass) of propellant to achieve and maintain the GEO orbit while performing the momentum unloads for 10 years.
Attitude Determination Using a MEMS-Based Flight Information Measurement Unit
Ma, Der-Ming; Shiau, Jaw-Kuen; Wang, I.-Chiang; Lin, Yu-Heng
2012-01-01
Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design. PMID:22368455
Attitude determination using a MEMS-based flight information measurement unit.
Ma, Der-Ming; Shiau, Jaw-Kuen; Wang, I-Chiang; Lin, Yu-Heng
2012-01-01
Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design.
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.
ERIC Educational Resources Information Center
Hwang, Alvin; Arbaugh, J. B.
2006-01-01
The electronic medium continues to play an increasingly important role in the delivery of management education despite a paucity of empirical studies on its impact and efficacy. Results from a study of competitive attitudes and feedback-seeking behaviors across seven "hybrid" electronic cum live classes showed that…
Organizational Learning and Large-Scale Change: Adoption of Electronic Medical Records
ERIC Educational Resources Information Center
Chavis, Virginia D.
2010-01-01
Despite implementation of electronic medical record (EMR) systems in the United States and other countries, there is no organizational development model that addresses medical professionals' attitudes toward technology adoption in a learning organization. The purpose of this study was to assess whether a model would change those attitudes toward…
Using spaced education to teach interns about teaching skills.
Pernar, Luise I M; Corso, Katherine; Lipsitz, Stuart R; Breen, Elizabeth
2013-07-01
Despite limited preparation and knowledge base, surgical interns have important teaching responsibilities. Nevertheless, few faculty development programs are aimed at interns. Succinct teaching skill content was electronically distributed over time (spaced education) to interns in academic year 2010/2011. The interns in the previous year served as historic controls. Electronic surveys were distributed for program evaluation. Fifteen of 24 (62.5%) interns and 35 of 49 (71.4%) students responded to the surveys in academic year 2009/2010 and 16 of 27 (59.3%) interns and 38 of 52 (73%) students responded in academic year 2010/2011. Surveys showed improved attitudes toward teaching by interns as well as a higher estimation of interns' teaching skills as rated by students for those interns who received the spaced education program. Using spaced education to improve interns' teaching skills is a potentially powerful intervention that improves interns' enthusiasm for teaching and teaching effectiveness. The changes are mirrored in students' ratings of interns' teaching skills and interns' attitudes toward teaching. Copyright © 2013 Elsevier Inc. All rights reserved.
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
Solar Dynamics Observatory Guidance, Navigation, and Control System Overview
NASA Technical Reports Server (NTRS)
Morgenstern, Wendy M.; Bourkland, Kristin L.; Hsu, Oscar C.; Liu, Kuo-Chia; Mason, Paul A. C.; O'Donnell, James R., Jr.; Russo, Angela M.; Starin, Scott R.; Vess, Melissa F.
2011-01-01
The Solar Dynamics Observatory (SDO) was designed and built at the Goddard Space Flight Center, launched from Cape Canaveral on February 11, 2010, and reached its final geosynchronous science orbit on March 16, 2010. The purpose of SDO is to observe the Sun and continuously relay data to a dedicated ground station. SDO remains Sun-pointing throughout most of its mission for the instruments to take measurements of the Sun. The SDO attitude control system (ACS) is a single-fault tolerant design. Its fully redundant attitude sensor complement includes sixteen coarse Sun sensors (CSSs), a digital Sun sensor (DSS), three two-axis inertial reference units (IRUs), and two star trackers (STs). The ACS also makes use of the four guide telescopes included as a part of one of the science instruments. Attitude actuation is performed using four reaction wheels assemblies (RWAs) and eight thrusters, with a single main engine used to provide velocity-change thrust for orbit raising. The attitude control software has five nominal control modes, three wheel-based modes and two 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. This paper details the final overall design of the SDO guidance, navigation, and control (GN&C) system and how it was used in practice during SDO launch, commissioning, and nominal operations. This overview will include the ACS control modes, attitude determination and sensor calibration, the high gain antenna (HGA) calibration, and jitter mitigation operation. The Solar Dynamics Observatory mission is part of the NASA Living With a Star program, which seeks to understand the changing Sun and its effects on the Solar System, life, and society. To this end, the SDO spacecraft carries three Sun-observing instruments: Helioseismic and Magnetic Imager (HMI), led by Stanford University; Atmospheric Imaging Assembly (AIA), led by Lockheed Martin Space and Astrophysics Laboratory; and Extreme Ultraviolet Variability Experiment (EVE), led by the University of Colorado. The basic mission is to observe the Sun for a very high percentage of the 5-year mission (10-year goal) with long stretches of uninterrupted observations and with constant, high-data-rate transmission to a dedicated ground station to be located in White Sands, New Mexico. These goals guided the design of the spacecraft bus that will carry and service the three-instrument payload. Overarching design goals for the bus are geosynchronous orbit, near-constant Sun observations with the ability to fly through eclipses, and constant HGA contact with the dedicated ground station. A three-axis stabilized ACS is needed both to point at the Sun accurately and to keep the roll about the Sun vector correctly positioned with respect to the solar north pole. This roll control is especially important for the magnetic field imaging of HM I. The mission requirements have several general impacts on the ACS design. Both the AIA and HMI instruments are very sensitive to the blurring caused by jitter. Each has an image stabilization system (ISS) with some ability to filter out high frequency motion, but below the bandwidth of the ISS the control system must compensate for disturbances within the ACS bandwidth or avoid exciting jitter at higher frequencies. Within the ACS bandwidth, the control requirement imposed by AIA is to place the center of the solar disk no more than 2 arc sec, 3 , from a body-defined target based on one of the GTs that accompany the instrument. This body-defined target, called the science reference boresight (SRB), was determined from the postlaunch orientation of the GTs by averaging the bounding telescope boresights for pitch to get a pitch SRB coordinate, and by averaging the bounding boresights for yaw toet the yaw SRB coordinate. The location of this SRB in the 0.5-deg field-of-view for each GT then becomes the central target for each telescope; one GT is selected for use as the ACS controlling guide telescope (CGT) at any given time. Fine Sun-pointing is effected based on this SRB for all three instruments when the Sun is within the linear range of the CGT. In addition to limiting jitter, HMI science requires averaging several observations, making the instrument sensitive to low frequency motion that induces differential motion between each observation. This requires the spacecraft attitude to be stable about the roll axis to approximately 10 arcsec over a ten-minute period. Instrument calibrations require that the spacecraft point the SRB up to 2.5 degrees in pitch and yaw away from the center of the Sun, placing the Sun outside the field-of-view of the guide telescopes. In such instances, when the GTs cannot provide the definitive target for the ACS, on-board attitude determination combined with ephemeris prediction of the Sun direction must provide the definitive target. EVE is capable of observing the Sun with less dependence on attitude control. However, the ground data processing needs for calibrations result in the most strict attitude knowledge requirements for the mission: [35,70,70] arcsec, 3 , of knowledge with respect to the center of the solar disk. In addition to driving the ACS sensor selection, the knowledge requirements, which have their effect primarily during Inertial mode calibrations, drive the accuracy requirements for the solar ephemeris. The need to achieve and maintain geosynchronous orbit (GEO) drove the need for high-efficiency propulsive systems and appropriate attitude control. The main engine provided high specific impulse for the maneuvers to attain GEO, while the smaller ACS thrusters managed the disturbance torques of the larger engine and provided the capability for much smaller adjustment burns on orbit. SDO s large solar profile means that solar radiation pressure is a large torque disturbance, and the momentum buildup from this disturbance and the GEO altitude drives the ACS to use thrusters to manage vehicle momentum. The demanding data capture budget for the mission, however, requires SDO to avoid frequent thruster maneuvers, while concerns about on-orbit jitter restrict the maximum desired wheel speeds desired from the RWAs. The plan for on-orbit wheel speed and momentum management will be discussed as well as what is now being done in operation after the jitter environment was characterized. The SDO ACS hardware complement is single-fault tolerant. Two main processors carry virtually identical copies of the command and data handling and ACS software, and two identical attitude control electronics (ACE) boxes carry Coldfire processors with contingency ACS software and other hardware interface cards; the ACE structure allows reaction wheels to be commanded by the Sun-pointing Safehold independent of the Mil Std 1553 data bus. The sixteen Adcole CSSs are grouped into primary and backup sets of eight sensors, each set providing the ability to calculate a sun vector. Each set of eight eyes provides full 4 -steradian coverage. The Adcole DSS comprises an optics head and a separate electronics box providing a 1553 data interface. The electronics box is mounted inside the Faraday cage created by the spacecraft bus module. The DSS head with its 32- deg square FOV is mounted on the instrument module with its boresight along the spacecraft X axis, nearly aligned with the Sun during observations. Adcole has designed the DSS calibration parameters so that the accuracy is 0.24 arcminutes within 10 deg of the boresight, and diminishes to 3 arcminutes as the Sun moves towards the edges of its FOV . This DSS calibration scheme provides higher accuracy attitude determination over the range of the instrument calibration maneuvers.
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.
Effects of an E-Learning Module on Students' Attitudes in an Electronics Class
ERIC Educational Resources Information Center
Getuno, Daniel M.; Kiboss, Joel K.; Changeiywo, Johnson M.; Ogola, Leo B.
2015-01-01
Research has shown that students exhibit negative attitudes towards Electronics especially when they are taught using the conventional method. This is in addition to poor instructional methods that do not promote individualization of instruction or make learning interesting. The purpose of this study was to design an e-learning module in…
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.
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
2001-01-02
KENNEDY SPACE CENTER, FLA. -- Space Shuttle Atlantis moves through the doors of the Vehicle Assembly Building on its rollout to Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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
2001-01-03
KENNEDY SPACE CENTER, Fla. -- At the top of the incline to Launch Pad 39A, Space Shuttle Atlantis nears the Rotating Service Structure (left). Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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
2001-01-02
KENNEDY SPACE CENTER, FLA. -- Space Shuttle Atlantis moves back inside the Vehicle Assembly Building after an aborted rollout to Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
1998 IEEE Aerospace Conference. Proceedings.
NASA Astrophysics Data System (ADS)
The following topics were covered: science frontiers and aerospace; flight systems technologies; spacecraft attitude determination and control; space power systems; smart structures and dynamics; military avionics; electronic packaging; MEMS; hyperspectral remote sensing for GVP; space laser technology; pointing, control, tracking and stabilization technologies; payload support technologies; protection technologies; 21st century space mission management and design; aircraft flight testing; aerospace test and evaluation; small satellites and enabling technologies; systems design optimisation; advanced launch vehicles; GPS applications and technologies; antennas and radar; software and systems engineering; scalable systems; communications; target tracking applications; remote sensing; advanced sensors; and optoelectronics.
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.
Frandes, Mirela; Deiac, Anca V; Timar, Bogdan; Lungeanu, Diana
2017-01-01
Nowadays, mobile technologies are part of everyday life, but the lack of instruments to assess their acceptability for the management of chronic diseases makes their actual adoption for this purpose slow. The objective of this study was to develop a survey instrument for assessing patients' attitude toward and intention to use mobile technology for diabetes mellitus (DM) self-management, as well as to identify sociodemographic characteristics and quality of life factors that affect them. We first conducted the documentation and instrument design phases, which were subsequently followed by the pilot study and instrument validation. Afterward, the instrument was administered 103 patients (median age: 37 years; range: 18-65 years) diagnosed with type 1 or type 2 DM, who accepted to participate in the study. The reliability and construct validity were assessed by computing Cronbach's alpha and using factor analysis, respectively. The instrument included statements about the actual use of electronic devices for DM management, interaction between patient and physician, attitude toward using mobile technology, and quality of life evaluation. Cronbach's alpha was 0.9 for attitude toward using mobile technology and 0.97 for attitude toward using mobile device applications for DM self-management. Younger patients (Spearman's ρ =-0.429; P <0.001) with better glycemic control (Spearman's ρ =-0.322; P <0.001) and higher education level (Kendall's τ =0.51; P <0.001) had significantly more favorable attitude toward using mobile assistive applications for DM control. Moreover, patients with a higher quality of life presented a significantly more positive attitude toward using modern technology (Spearman's ρ =0.466; P <0.001). The instrument showed good reliability and internal consistency, making it suitable for measuring the acceptability of mobile technology for DM self-management. Additionally, we found that even if most of the patients showed positive attitude toward mobile applications, only a moderate level of intention to indeed use them was observed. Moreover, the study indicated that barriers were truthfulness and easiness to use.
Flywheels Upgraded for Systems Research
NASA Technical Reports Server (NTRS)
Jansen, Ralph H.
2003-01-01
With the advent of high-strength composite materials and microelectronics, flywheels are becoming attractive as a means of storing electrical energy. In addition to the high energy density that flywheels provide, other advantages over conventional electrochemical batteries include long life, high reliability, high efficiency, greater operational flexibility, and higher depths of discharge. High pulse energy is another capability that flywheels can provide. These attributes are favorable for satellites as well as terrestrial energy storage applications. In addition to energy storage for satellites, the several flywheels operating concurrently can provide attitude control, thus combine two functions into one system. This translates into significant weight savings. The NASA Glenn Research Center is involved in the development of this technology for space and terrestrial applications. Glenn is well suited for this research because of its world-class expertise in power electronics design, rotor dynamics, composite material research, magnetic bearings, and motor design and control. Several Glenn organizations are working together on this program. The Structural Mechanics and Dynamics Branch is providing magnetic bearing, controls, and mechanical engineering skills. It is working with the Electrical Systems Development Branch, which has expertise in motors and generators, controls, and avionics systems. Facility support is being provided by the Space Electronic Test Engineering Branch, and the program is being managed by the Space Flight Project Branch. NASA is funding an Aerospace Flywheel Technology Development Program to design, fabricate, and test the Attitude Control/Energy Storage Experiment (ACESE). Two flywheels will be integrated onto a single power bus and run simultaneously to demonstrate a combined energy storage and 1-degree-of-freedom momentum control system. An algorithm that independently regulates direct-current bus voltage and net torque output will be experimentally demonstrated.
Chisholm, Alison; Price, David B; Pinnock, Hilary; Lee, Tan Tze; Roa, Camilo; Cho, Sang-Heon; David-Wang, Aileen; Wong, Gary; van der Molen, Thys; Ryan, Dermot; Castillo-Carandang, Nina; Yong, Yee Vern
2017-01-05
REALISE Asia-an online questionnaire-based study of Asian asthma patients-identified five patient clusters defined in terms of their control status and attitude towards their asthma (categorised as: 'Well-adjusted and at least partly controlled'; 'In denial about symptoms'; 'Tolerating with poor control'; 'Adrift and poorly controlled'; 'Worried with multiple symptoms'). We developed consensus recommendations for tailoring management of these attitudinal-control clusters. An expert panel undertook a three-round electronic Delphi (e-Delphi): Round 1: panellists received descriptions of the attitudinal-control clusters and provided free text recommendations for their assessment and management. Round 2: panellists prioritised Round 1 recommendations and met (or joined a teleconference) to consolidate the recommendations. Round 3: panellists voted and prioritised the remaining recommendations. Consensus was defined as Round 3 recommendations endorsed by >50% of panellists. Highest priority recommendations were those receiving the highest score. The multidisciplinary panellists (9 clinicians, 1 pharmacist and 1 health social scientist; 7 from Asia) identified consensus recommendations for all clusters. Recommended pharmacological (e.g., step-up/down; self-management; simplified regimen) and non-pharmacological approaches (e.g., trigger management, education, social support; inhaler technique) varied substantially according to each cluster's attitude to asthma and associated psychosocial drivers of behaviour. The attitudinal-control clusters defined by REALISE Asia resonated with the international panel. Consensus was reached on appropriate tailored management approaches for all clusters. Summarised and incorporated into a structured management pathway, these recommendations could facilitate personalised care. Generalisability of these patient clusters should be assessed in other socio-economic, cultural and literacy groups and nationalities in Asia.
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.
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.
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.
ERIC Educational Resources Information Center
Omidian, Faranak; Nedayeh Ali, Farzaneh
2015-01-01
The aim of this study was to investigate the attitudes of students, instructors, and educational principals to electronic administration of final-semester examinations at undergraduate and post- graduate levels in Payame Noor University in Khuzestan. The statistical population of this study consisted of all educational principals, instructors, of…
A survey of current solid state star tracker technology
NASA Astrophysics Data System (ADS)
Armstrong, R. W.; Staley, D. A.
1985-12-01
This paper is a survey of the current state of the art in design of star trackers for spacecraft attitude determination systems. Specific areas discussed are sensor technology, including the current state-of-the-art solid state sensors and techniques of mounting and cooling the sensor, analog image preprocessing electronics performance, and digital processing hardware and software. Three examples of area array solid state star tracker development are presented - ASTROS, developed by the Jet Propulsion Laboratory, the Retroreflector Field Tracker (RFT) by Ball Aerospace, and TRW's MADAN. Finally, a discussion of solid state line arrays explores the possibilities for one-dimensional imagers which offer simplified scan control electronics.
Social Media and eBusiness: Cultural Impacts on the Influence Process in Consumer Communities
NASA Astrophysics Data System (ADS)
Chen, Yong; Chen, Hong; Xu, Li
2016-08-01
Social media has been used as an important tool by firms to influence consumers’ attitude and behavior. Influence occurs in consumer communities in social media because community members have the control of discovering, producing, sharing, and distributing information and because the spread out of their experiences and opinions in the format of electronic word-of-mouth forms emerging conformance. Prior research has explored how the influence occurring in online social media communities impacts consumers’ attitude and behavior (e.g., product attitude and purchase decision, effectual thinking and behavior, brand trust and brand loyalty). But because social media has the ability of global reach, cross-border factors should not be neglected in studying the influence process. As such, this paper adopts national cultural dimensions identified by Hofstede (1984), individualism/collectivism and power distance particularly, the index of cultural distance, and the social influence theory to explore how culture impacts the influence occurring in consumer communities in social media.
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.
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...
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,
Electrospray Thrusters for Attitude Control of a 1-U CubeSat
NASA Astrophysics Data System (ADS)
Timilsina, Navin
With a rapid increase in the interest in use of nanosatellites in the past decade, finding a precise and low-power-consuming attitude control system for these satellites has been a real challenge. In this thesis, it is intended to design and test an electrospray thruster system that could perform the attitude control of a 1-unit CubeSat. Firstly, an experimental setup is built to calculate the conductivity of different liquids that could be used as propellants for the CubeSat. Secondly, a Time-Of-Flight experiment is performed to find out the thrust and specific impulse given by these liquids and hence selecting the optimum propellant. On the other hand, a colloidal thruster system for a 1-U CubeSat is designed in Solidworks and fabricated using Lathe and CNC Milling Machine. Afterwards, passive propellant feeding is tested in this thruster system. Finally, the electronic circuit and wireless control system necessary to remotely control the CubeSat is designed and the final testing is performed. Among the propellants studied, Ethyl ammonium nitrate (EAN) was selected as the best propellant for the CubeSat. Theoretical design and fabrication of the thruster system was performed successfully and so was the passive propellant feeding test. The satellite was assembled for the final experiment but unfortunately the microcontroller broke down during the first test and no promising results were found out. However, after proving that one thruster works with passive feeding, it could be said that the ACS testing would have worked if we had performed vacuum compatibility tests for other components beforehand.
Panoramic attitude sensor for Radio Astronomy Explorer B
NASA Technical Reports Server (NTRS)
Thomsen, R.
1973-01-01
An instrument system to acquire attitude determination data for the RAE-B spacecraft was designed and built. The system consists of an electronics module and two optical scanner heads. Each scanner head has an optical scanner with a field of view of 0.7 degrees diameter which scans the sky and measures the position of the moon, earth and sun relative to the spacecraft. This scanning is accomplished in either of two modes. When the spacecraft is spinning, the scanner operates in spherical mode, with the spacecraft spin providing the slow sweep of lattitude to scan the entire sky. After the spacecraft is placed in lunar orbit and despun, the scanner will operate in planar mode, advancing at a rate of 5.12 seconds per revolution in a fixed plane parallel to the spacecraft Z axis. This scan will cross and measure the moon horizons with every revolution. Each scanner head also has a sun slit which is aligned parallel to the spin axis of the spacecraft and which provides a sun pulse each revolution of the spacecraft. The electronics module provides the command and control, data processing and housekeeping functions.
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.
ERIC Educational Resources Information Center
Romi, Shlomo; Hansenson, Gabriel; Hansenson, Arie
2002-01-01
Describes a study in Israel that was conducted to examine the attitudes of dropout adolescents to electronic learning and to compare these to the attitudes of normative 10th graders. Considers demographic differences, including parents' education and computer ownership; motivation; enjoyment; cognition; and accessibility of computers. (LRW)
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.
Horizon sensors attitude errors simulation for the Brazilian Remote Sensing Satellite
NASA Astrophysics Data System (ADS)
Vicente de Brum, Antonio Gil; Ricci, Mario Cesar
Remote sensing, meteorological and other types of satellites require an increasingly better Earth related positioning. From the past experience it is well known that the thermal horizon in the 15 micrometer band provides conditions of determining the local vertical at any time. This detection is done by horizon sensors which are accurate instruments for Earth referred attitude sensing and control whose performance is limited by systematic and random errors amounting about 0.5 deg. Using the computer programs OBLATE, SEASON, ELECTRO and MISALIGN, developed at INPE to simulate four distinct facets of conical scanning horizon sensors, attitude errors are obtained for the Brazilian Remote Sensing Satellite (the first one, SSR-1, is scheduled to fly in 1996). These errors are due to the oblate shape of the Earth, seasonal and latitudinal variations of the 15 micrometer infrared radiation, electronic processing time delay and misalignment of sensor axis. The sensor related attitude errors are thus properly quantified in this work and will, together with other systematic errors (for instance, ambient temperature variation) take part in the pre-launch analysis of the Brazilian Remote Sensing Satellite, with respect to the horizon sensor performance.
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.
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.
Dynamic Control System Mode Performance of the Space Technology-7 Disturbance Reduction System
NASA Technical Reports Server (NTRS)
O'Donnell, James R., Jr.; Hsu, Oscar; Maghami, Peiman
2017-01-01
The Space Technology-7 (ST-7) Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft, launched on December 3, 2015. DRS consists of three primary components: Colloidal MicroNewton Thrusters (CMNTs), an Integrated Avionics Unit (IAU), and flight-software implementing the Command and Data Handling (C&DH) and Dynamic Control System (DCS) algorithms. The CMNTs were designed to provide thrust from 5 to 30 micro Newton, with thrust controllability and resolution of 0.1 micro Newton and thrust noise of 0.1 micro Newton/(square root of (Hz)) in the measurement band from 1-30 mHz. The IAU hosts the C&DH and DCS flight software, as well as interfaces with both the CMNT electronics and the LISA Pathfinder spacecraft. When in control, the DCS uses star tracker attitude data and capacitive or optically-measured position and attitude information from LISA Pathfinder and the LISA Technology Package (LTP) to control the attitude and position of the spacecraft and the two test masses inside the LTP. After completion of the nominal ESA LISA Pathfinder mission, the DRS experiment was commissioned followed by its nominal mission. DRS operations extended over the next five months, interspersed with station keeping, anomaly resolution, and periods where control was handed back to LISA Pathfinder for them to conduct further experiments. The primary DRS mission ended on December 6, 2016, with the experiment meeting all of its Level 1 requirements. The DCS, developed at the NASA Goddard Space Flight Center, consists of five spacecraft control modes and six test mass control modes, combined into six 'DRS Mission Modes'. Attitude Control and Zero-G were primarily used to control the spacecraft during initial handover and during many of the CMNT characterization experiments. The other Mission Modes, Drag Free Low Force, 18-DOF Transitional, and 18-DOF, were used to provide drag-free control of the spacecraft about the test masses. This paper will discuss the performance of these DCS spacecraft and test mass control modes. Flight data will be shown from each mode throughout the mission, both from nominal operations and during various flight experiments. The DCS team also made some changes to controller, filter, and limit parameters during operations; the motivation and results of these changes will be shown and discussed.
ERIC Educational Resources Information Center
Aljaser, Afaf M.
2017-01-01
The present study aimed to identify the effect of using electronic Mind Maps on the academic achievement of the fifth-grade primary female students in the English language curriculum compared to the traditional teaching method adopted in the teacher's guide. It also aimed to indicate the attitudes of the fifth-grade female students towards the use…
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…
NASA Technical Reports Server (NTRS)
Martin, William Campbell
2011-01-01
The Jet Propulsion Laboratory (JPL) is developing the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) to assist in manned space missions. One of the proposed targets for this robotic vehicle is a near-Earth asteroid (NEA), which typically exhibit a surface gravity of only a few micro-g. In order to properly test ATHLETE in such an environment, the development team has constructed an inverted Stewart platform testbed that acts as a robotic motion simulator. This project focused on creating physical simulation software that is able to predict how ATHLETE will function on and around a NEA. The corresponding platform configurations are calculated and then passed to the testbed to control ATHLETE's motion. In addition, imitation attitude, imitation attitude control thrusters were designed and fabricated for use on ATHLETE. These utilize a combination of high power LEDs and audio amplifiers to provide visual and auditory cues that correspond to the physics simulation.
Vehicle charging and potential on the STS-3 mission
NASA Technical Reports Server (NTRS)
Williamson, R.
1983-01-01
An electron gun with fast pulse capability was used in the vehicle charging and potential experiment carried on the OSS-1 pallet to study dielectric charging, return current mechanisms, and the techniques required to manage the electrical charging of the orbiter. Return currents and charging of the dielectrics were measured during electron beam emission and plasma characteristics in the payload bay were determined in the absence of electron beam emission. The fast pulse electron generator, charge current probes, spherical retarding potential analyzer, and the digital control interface unit which comprise the experiment are described. Results show that the thrusters produce disturbances which are variable in character and magnitude. Strong ram/wake effects were seen in the ion densities in the bay. Vehicle potentials are variable with respect to the plasma and depend upon location on the vehicle relative to the main engine nozzles, the vehicle attitude, and the direction of the geomagnetic field.
Ma, Chen-Chung; Kuo, Kuang-Ming; Alexander, Judith W
2016-02-02
The purpose of this study is to investigate factors that motivate nurses to protect privacy in electronic medical records, based on the Decomposed Theory of Planned Behavior. This cross-sectional study used questionnaires to collect data from nurses in a large tertiary care military hospital in Taiwan. The three hundred two (302) valid questionnaires returned resulted in a response rate of 63.7 %. Structural equation modeling identified that the factors of attitude, subjective norm, and perceived behavioral control of the nurses significantly predicted the nurses' intention to protect the privacy of electronic medical records. Further, perceived usefulness and compatibility, peer and superior influence, self-efficacy and facilitating conditions, respectively predicted these three factors. The results of our study may provide valuable information for education and practice in predicting nurses' intention to protect privacy of electronic medical records.
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
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
2001-01-02
KENNEDY SPACE CENTER, FLA. -- Viewed from inside the Vehicle Assembly Building, Space Shuttle Atlantis moves back inside after an aborted rollout to Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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. -- 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
2001-01-02
KENNEDY SPACE CENTER, FLA. -- Seen from outside, Space Shuttle Atlantis moves back inside the Vehicle Assembly Building after an aborted rollout to Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
2001-01-02
KENNEDY SPACE CENTER, FLA. -- In the Vehicle Assembly Building, Space Shuttle Atlantis is viewed from overhead just before beginning rollout to Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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. -- 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
2001-01-03
KENNEDY SPACE CENTER, Fla. -- Under wispy white clouds, Space Shuttle Atlantis slowly moves toward the Rotating and Fixed Service Structures on Launch Pad 39A. The 80-foot-tall white lighting mast is seen atop the FSS. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
Spacecraft attitude control using a smart control system
NASA Technical Reports Server (NTRS)
Buckley, Brian; Wheatcraft, Louis
1992-01-01
Traditionally, spacecraft attitude control has been implemented using control loops written in native code for a space hardened processor. The Naval Research Lab has taken this approach during the development of the Attitude Control Electronics (ACE) package. After the system was developed and delivered, NRL decided to explore alternate technologies to accomplish this same task more efficiently. The approach taken by NRL was to implement the ACE control loops using systems technologies. The purpose of this effort was to: (1) research capabilities required of an expert system in processing a classic closed-loop control algorithm; (2) research the development environment required to design and test an embedded expert systems environment; (3) research the complexity of design and development of expert systems versus a conventional approach; and (4) test the resulting systems against the flight acceptance test software for both response and accuracy. Two expert systems were selected to implement the control loops. Criteria used for the selection of the expert systems included that they had to run in both embedded systems and ground based environments. Using two different expert systems allowed a comparison of the real-time capabilities, inferencing capabilities, and the ground-based development environment. The two expert systems chosen for the evaluation were Spacecraft Command Language (SCL), and NEXTPERT Object. SCL is a smart control system produced for the NRL by Interface and Control Systems (ICS). SCL was developed to be used for real-time command, control, and monitoring of a new generation of spacecraft. NEXPERT Object is a commercially available product developed by Neuron Data. Results of the effort were evaluated using the ACE test bed. The ACE test bed had been developed and used to test the original flight hardware and software using simulators and flight-like interfaces. The test bed was used for testing the expert systems in a 'near-flight' environment. The technical approach, the system architecture, the development environments, knowledge base development, and results of this effort are detailed.
The Juno Magnetic Field Investigation
NASA Astrophysics Data System (ADS)
Connerney, J. E. P.; Benn, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.; Murphy, S.; Odom, J.; Oliversen, R.; Schnurr, R.; Sheppard, D.; Smith, E. J.
2017-11-01
The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to ˜20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 × 106 nT per axis) with a resolution of ˜0.05 nT in the most sensitive dynamic range (±1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of view and also provides a continuous record of radiation exposure. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors, and residual spacecraft fields and/or sensor offsets are monitored in flight taking advantage of Juno's spin (nominally 2 rpm) to separate environmental fields from those that rotate with the spacecraft.
The Juno Magnetic Field Investigation
NASA Technical Reports Server (NTRS)
Connerney, J. E. P.; Benna, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.;
2017-01-01
The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to approx. 20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 x 10(exp. 6) nT per axis) with a resolution of approx. 0.05 nT in the most sensitive dynamic range (+/-1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of view and also provides a continuous record of radiation exposure. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors, and residual spacecraft fields andor sensor offsets are monitored in flight taking advantage of Juno's spin (nominally 2 rpm) to separate environmental fields from those that rotate with the spacecraft.
Employee Attitudes Regarding Electronic Mail Policies: A Case Study.
ERIC Educational Resources Information Center
Hacker, Kenneth L.; Goss, Blaine; Townley, Charles; Horton, Valerie J.
1998-01-01
Investigates attitudes toward e-mail and e-mail policies through a case study of e-mail users at a university library. Indicates those who use e-mail frequently have more favorable attitudes to it than less frequent users and are more opposed to policies regulating e-mail communication. Notes that employees prefer guidelines to restrictive…
ERIC Educational Resources Information Center
Da'asin, Khaled Awad
2016-01-01
This study aimed to investigate the attitude of Ash-Shobak university college students concerning the electronic exam for intermediate university degree in Jordan, and identify the impact of gender and grade point average (GPA) variables on students' attitudes. To achieve this objective, a questionnaire consisting of (26) items was used, and…
ERIC Educational Resources Information Center
Alkaria, Ahmed; Alhassan, Riyadh
2017-01-01
This study was conducted to examine the effect of in-service training of computer science teachers in Scratch language using an electronic learning platform on acquiring programming skills and attitudes towards teaching programming. The sample of this study consisted of 40 middle school computer science teachers. They were assigned into two…
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…
ERIC Educational Resources Information Center
Altawallbeh, Manal; Soon, Fong; Thiam, Wun; Alshourah, Sultan
2015-01-01
The purpose of this study is to examine the factors that determine intention to adopt e-learning in Jordanian universities. Two models of e-learning that are observed among adopting institutions: E-learning as a supplement to traditional classroom mode, and total electronic learning. The respondents in this research have just been introduced to…
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.
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.
Radar Attitude Sensing System (RASS)
NASA Technical Reports Server (NTRS)
1971-01-01
The initial design and fabrication efforts for a radar attitude sensing system (RASS) are covered. The design and fabrication of the RASS system is being undertaken in two phases, 1B1 and 1B2. The RASS system as configured under phase 1B1 contains the solid state transmitter and local oscillator, the antenna system, the receiving system, and the altitude electronics. RASS employs a pseudo-random coded cw signal and receiver correlation techniques to measure range. The antenna is a planar, phased array, monopulse type, whose beam is electronically steerable using diode phase shifters. The beam steering computer and attitude sensing circuitry are to be included in Phase 1B2 of the program.
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).
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 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.
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.
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
Frandes, Mirela; Deiac, Anca V; Timar, Bogdan; Lungeanu, Diana
2017-01-01
Background Nowadays, mobile technologies are part of everyday life, but the lack of instruments to assess their acceptability for the management of chronic diseases makes their actual adoption for this purpose slow. Objective The objective of this study was to develop a survey instrument for assessing patients’ attitude toward and intention to use mobile technology for diabetes mellitus (DM) self-management, as well as to identify sociodemographic characteristics and quality of life factors that affect them. Methods We first conducted the documentation and instrument design phases, which were subsequently followed by the pilot study and instrument validation. Afterward, the instrument was administered 103 patients (median age: 37 years; range: 18–65 years) diagnosed with type 1 or type 2 DM, who accepted to participate in the study. The reliability and construct validity were assessed by computing Cronbach’s alpha and using factor analysis, respectively. Results The instrument included statements about the actual use of electronic devices for DM management, interaction between patient and physician, attitude toward using mobile technology, and quality of life evaluation. Cronbach’s alpha was 0.9 for attitude toward using mobile technology and 0.97 for attitude toward using mobile device applications for DM self-management. Younger patients (Spearman’s ρ=−0.429; P<0.001) with better glycemic control (Spearman’s ρ=−0.322; P<0.001) and higher education level (Kendall’s τ=0.51; P<0.001) had significantly more favorable attitude toward using mobile assistive applications for DM control. Moreover, patients with a higher quality of life presented a significantly more positive attitude toward using modern technology (Spearman’s ρ=0.466; P<0.001). Conclusion The instrument showed good reliability and internal consistency, making it suitable for measuring the acceptability of mobile technology for DM self-management. Additionally, we found that even if most of the patients showed positive attitude toward mobile applications, only a moderate level of intention to indeed use them was observed. Moreover, the study indicated that barriers were truthfulness and easiness to use. PMID:28243069
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…
Goldzweig, Caroline Lubick; Orshansky, Greg; Paige, Neil M; Towfigh, Ali Alexander; Haggstrom, David A; Miake-Lye, Isomi; Beroes, Jessica M; Shekelle, Paul G
2013-11-19
Patient portals tied to provider electronic health record (EHR) systems are increasingly popular. To systematically review the literature reporting the effect of patient portals on clinical care. PubMed and Web of Science searches from 1 January 1990 to 24 January 2013. Hypothesis-testing or quantitative studies of patient portals tethered to a provider EHR that addressed patient outcomes, satisfaction, adherence, efficiency, utilization, attitudes, and patient characteristics, as well as qualitative studies of barriers or facilitators, were included. Two reviewers independently extracted data and addressed discrepancies through consensus discussion. From 6508 titles, 14 randomized, controlled trials; 21 observational, hypothesis-testing studies; 5 quantitative, descriptive studies; and 6 qualitative studies were included. Evidence is mixed about the effect of portals on patient outcomes and satisfaction, although they may be more effective when used with case management. The effect of portals on utilization and efficiency is unclear, although patient race and ethnicity, education level or literacy, and degree of comorbid conditions may influence use. Limited data for most outcomes and an absence of reporting on organizational and provider context and implementation processes. Evidence that patient portals improve health outcomes, cost, or utilization is insufficient. Patient attitudes are generally positive, but more widespread use may require efforts to overcome racial, ethnic, and literacy barriers. Portals represent a new technology with benefits that are still unclear. Better understanding requires studies that include details about context, implementation factors, and cost.
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.
Beeckman, Dimitri; Clays, Els; Van Hecke, Ann; Vanderwee, Katrien; Schoonhoven, Lisette; Verhaeghe, Sofie
2013-04-01
Frail older people admitted to nursing homes are at risk of a range of adverse outcomes, including pressure ulcers. Clinical decision support systems are believed to have the potential to improve care and to change the behaviour of healthcare professionals. To determine whether a multi-faceted tailored strategy to implement an electronic clinical decision support system for pressure ulcer prevention improves adherence to recommendations for pressure ulcer prevention in nursing homes. Two-armed randomized controlled trial in a nursing home setting in Belgium. The trial consisted of a 16-week implementation intervention between February and June 2010, including one baseline, four intermediate, and one post-testing measurement. Primary outcome was the adherence to guideline-based care recommendations (in terms of allocating adequate pressure ulcer prevention in residents at risk). Secondary outcomes were the change in resident outcomes (pressure ulcer prevalence) and intermediate outcomes (knowledge and attitudes of healthcare professionals). Random sample of 11 wards (6 experimental; 5 control) in a convenience sample of 4 nursing homes in Belgium. In total, 464 nursing home residents and 118 healthcare professionals participated. The experimental arm was involved in a multi-faceted tailored implementation intervention of a clinical decision support system, including interactive education, reminders, monitoring, feedback and leadership. The control arm received a hard-copy of the pressure ulcer prevention protocol, supported by standardized 30 min group lecture. Patients in the intervention arm were significantly more likely to receive fully adequate pressure ulcer prevention when seated in a chair (F=16.4, P=0.003). No significant improvement was observed on pressure ulcer prevalence and knowledge of the professionals. While baseline attitude scores were comparable between both groups [exp. 74.3% vs. contr. 74.5% (P=0.92)], the mean score after the intervention was 83.5% in the experimental group vs. 72.1% in the control group (F=15.12, P<0.001). The intervention was only partially successful to improve the primary outcome. Attitudes improved significantly while the knowledge of the healthcare workers remained unsatisfactorily low. Further research should focus on the underlying reasons for these findings. Copyright © 2012 Elsevier Ltd. All rights reserved.
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.
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
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.
Health Risks Awareness of Electronic Waste Workers in the Informal Sector in Nigeria.
Ohajinwa, Chimere M; Van Bodegom, Peter M; Vijver, Martina G; Peijnenburg, Willie J G M
2017-08-13
Insight into the health risk awareness levels of e-waste workers is important as it may offer opportunities for better e-waste recycling management strategies to reduce the health effects of informal e-waste recycling. Therefore, this study assessed the knowledge, attitude, and practices associated with occupational health risk awareness of e-waste workers compared with a control group (butchers) in the informal sector in Nigeria. A cross-sectional study was used to assess health risk awareness of 279 e-waste workers (repairers and dismantlers) and 221 butchers from the informal sector in three locations in Nigeria in 2015. A questionnaire was used to obtain information on socio-demographic backgrounds, occupational history, knowledge, attitude, and work practices. The data was analysed using Analysis of Variance. The three job designations had significantly different knowledge, attitude, and practice mean scores ( p = 0.000), with butchers consistently having the highest mean scores. Only 43% of e-waste workers could mention one or more Personal Protective Equipment needed for their job compared with 70% of the butchers. The health risk awareness level of the e-waste workers was significantly lower compared with their counterparts in the same informal sector. A positive correlation existed between the workers' knowledge and their attitude and practice. Therefore, increasing the workers' knowledge may decrease risky practices.
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.
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.
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.
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.
Lee, Young-Shin
2015-03-01
To identify attitudes and bias toward aging between Asian and White students and identify factors affecting attitudes toward aging. A cross-sectional sample of 308 students in a nursing program completed the measure of Attitudes Toward Older People and Aging Quiz electronically. There were no differences in positive attitudes and pro-aged bias between Asian and White groups, but Asian students had significantly more negative attitudes and anti-aged bias toward older people than White students. Multiple regression analysis showed ethnicity/race was the strongest variable to explain negative attitudes toward older people. Feeling uneasy about talking to older adults was the most significant factor to explain all attitudinal concepts. Asian students were uneasy about talking with older people and had negative attitudes toward older adults. To become competent in cross-cultural care and communication in nursing, educational strategies to reduce negative attitudes on aging are necessary. © The Author(s) 2014.
Lim, Fidelindo A; Hsu, Richard
2016-01-01
The aim of this study was to critically appraise and synthesize findings from studies on the attitudes of nursing students toward lesbian, gay, bisexual, and transgender (LGBT) persons. There is paucity of research to assess the attitudes of nursing students toward LGBT persons. An electronic search was conducted using PubMed, Medline, Web of Science, EbscoHost, PsycInfo, and the Cumulative Index to Nursing and Allied Health Literature using medical subject headings terminologies. Search terms used included gay, lesbian, transgender, bisexual, LGBT, nursing students, baccalaureate nursing, undergraduate nursing, homophobia, homosexuality, sexual minority, attitudes, discrimination, and prejudice. Less than 50 percent of the studies (5 out of 12) suggested positively leaning attitudes of nursing students toward LGBT persons; six studies reported negative attitudes, and one study reported neutral attitudes. There are some indications that student attitudes may be moving toward positively leaning. Studies published before 2000 reported a preponderance of negative attitudes.
2000-12-04
Atlantis rolls into the transfer aisle of the Vehicle Assembly Building where it will be raised to vertical and lifted into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew (center of the photo) look over part of the payload. From left are Mission Specialists Robert Curbeam, Tom Jones and Marsha Ivins. 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, the STS-98 crew talks with United Space Alliance worker Larry Oshein (right). Standing left to right are Mission Specialist Robert Curbeam, Commander Ken Cockrell, Mission Specialist Tom Jones, and Mission Specialists Mark Polansky and Marsha Ivins. 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
2001-01-03
KENNEDY SPACE CENTER, Fla. -- At the top of Launch Pad 39A, Space Shuttle Atlantis closes in on the Rotating Service Structure (left). On the RSS, the payload canister can be seen half way up the structure as it is lifted to the Payload Changeout Room. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
2000-11-18
KENNEDY SPACE CENTER, FLA. -- In Orbiter Processing Facility bay 3, the STS-98 crew talks with United Space Alliance worker Larry Oshein (right). Standing left to right are Mission Specialist Robert Curbeam, Commander Ken Cockrell, Mission Specialist Tom Jones, and Mission Specialists Mark Polansky and Marsha Ivins. 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
2001-01-02
KENNEDY SPACE CENTER, Fla. -- Under gray cloudy skies, Space Shuttle Atlantis inches its way to Launch Pad 39A , barely visible in the background. The journey is a distance of just over 3 miles. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew (center of the photo) look over part of the payload. From left are Mission Specialists Robert Curbeam, Tom Jones and Marsha Ivins. 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
2000-12-04
Atlantis rolls into the transfer aisle of the Vehicle Assembly Building where it will be raised to vertical and lifted into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew look over part of the payload. At center is Mission Specialist Robert Curbeam; at right are Mission Specialists Marsha Ivins (standing) and Tom Jones (kneeling). 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. -- Lowered into the payload bay of the orbiter Atlantis, some of the STS-98 crew look over part of the payload. At center is Mission Specialist Robert Curbeam; at right are Mission Specialists Marsha Ivins (standing) and Tom Jones (kneeling). 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
NASA Technical Reports Server (NTRS)
Janson, Siegfried
2017-01-01
A Brane Craft is a membrane spacecraft with solar cells, command and control electronics, communications systems, antennas, propulsion systems, attitude and proximity sensors, and shape control actuators as thin film structures manufactured on 10 micron thick plastic sheets. This revolutionary spacecraft design can have a thickness of tens of microns with a surface area of square meters to maximize area-to-mass ratios for exceptionally low-mass spacecraft. Communications satellites, solar power satellites, solar electric propulsion stages, and solar sails can benefit from Brane Craft design. It also enables new missions that require low-mass spacecraft with exceptionally high delta-V. Active removal of orbital debris from Earth orbit is the target application for this study.
STS-98 Atlantis rolls out to Pad 39A for the second time
NASA Technical Reports Server (NTRS)
2001-01-01
KENNEDY SPACE CENTER, Fla. -- Under wispy white clouds, Space Shuttle Atlantis slowly moves toward the Rotating and Fixed Service Structures on Launch Pad 39A. The 80-foot-tall white lighting mast is seen atop the FSS. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five.
Kamin, C; Glicken, A; Hall, M; Quarantillo, B; Merenstein, G
2001-01-01
As course directors, we wished to incorporate small group learning into our Evidence-based Medicine course for students to get feedback on the development of a well constructed, researchable clinical question. Scheduling of these groups was problematic. We sought to evaluate computer-mediated communication as an alternative to face-to-face small groups. Students were randomly assigned to either face-to-face small groups or asynchronous, electronic, small groups. Final examination scores were analyzed with an analysis of variance to determine if there were differences in student performance based on group type. Student survey items were analyzed using Fisher's Exact test to determine if there were differences in student attitudes based on group type. There were no significant differences found in overall student performance. Significant differences in student attitudes were found to exist with respect to: (1) participation in discussions, with face-to-face groups reporting greater participation; (2) putting more thought into comments, with electronic groups reporting more thought put into comments; and (3) difficulty relating to other students in the class, with electronic groups reporting more difficulty. We found electronic discussion groups (computer-mediated communication) to be a viable teaching/learning strategy with no adverse effects on student performance or attitudes.
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.
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.
NASA Astrophysics Data System (ADS)
Nguyen, Quoc-Viet; Chan, Woei Leong; Debiasi, Marco
2015-03-01
We present our recent flying insect-inspired Flapping-Wing Micro Air Vehicle (FW-MAV) capable of hovering flight which we have recently achieved. The FW-MAV has wing span of 22 cm (wing tip-to-wing tip), weighs about 16.6 grams with onboard integration of radio control system including a radio receiver, an electronic speed control (ESC) for brushless motor, three servos for attitude flight controls of roll, pitch, and yaw, and a single cell lithium-polymer (LiPo) battery (3.7 V). The proposed gear box enables the FW-MAV to use one DC brushless motor to synchronously drive four wings and take advantage of the double clap-and-fling effects during one flapping cycle. Moreover, passive wing rotation is utilized to simplify the design, in addition to passive stabilizing surfaces for flight stability. Powered by a single cell LiPo battery (3.7 V), the FW-MAV flaps at 13.7 Hz and produces an average vertical force or thrust of about 28 grams, which is sufficient for take-off and hovering flight. Finally, free flight tests in terms of vertical take-off, hovering, and manual attitude control flight have been conducted to verify the performance of the FW-MAV.
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.
Wekre, Liv Johanne; Bakken, Kjersti; Garåsen, Helge; Grimsmo, Anders
2012-08-01
This study addresses GPs' attitudes towards multidose drug dispensing before and after implementation and their perceived experience of how multidose drug dispensing affects prescription and communication routines for patients in the home care services. This study contributes to a method triangulation with two other studies on the introduction of multidose drug dispensing in Trondheim. A controlled before-and-after study carried out in Trondheim (intervention) and Tromsø (control). A questionnaire was distributed to all GPs in the two towns in 2005 with a follow-up questionnaire in 2008. The GPs in Trondheim showed a positive attitude to multidose drug dispensing both before and after the implementation. Increased workload was reported, but still the GPs wanted the system to be continued. Most of the GPs reported a better overview of the patients' medication and a supposed reduction in medication errors. The GPs' prescription- and communication routines were changed only for the multidose drug users and not for the other patients in the home care services. The study supports the results presented in two previous publications according to GPs' positive attitude towards multidose drug dispensing, their better overview of the patients' medications, and improved cooperation with the pharmacy. This study adds to our understanding of prescription routines among GPs and the use of the medication module in the electronic health record.
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.
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.
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.
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.
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.
Przybylski, Andrew K; Weinstein, Netta
2016-01-01
Theories regarding the influences of electronic games drive scientific study, popular debate, and public policy. The fractious interchanges among parents, pundits, and scholars hint at the rich phenomenological and psychological dynamics that underlie how people view digital technologies such as games. The current research applied Martin Heidegger's concept of interpretive frameworks (Heidegger, 1987) and Robert Zajonc's exposure-attitude hypothesis (Zajonc, 1968) to explore how attitudes towards technologies such as electronic games arise. Three studies drew on representative cohorts of American and British adults and evaluated how direct and indirect experiences with games shape how they are seen. Results indicated this approach was fruitful: negative attitudes and beliefs linking games to real-world violence were prominent among those with little direct exposure to electronic gaming contexts, whereas those who played games and reported doing so with their children tended to evaluate gaming more positively. Further findings indicated direct experience tended to inform the accuracy of beliefs about the effects of digital technology, as those who had played were more likely to believe that which is empirically known about game effects. Results are discussed with respect to ongoing debates regarding gaming and broader applications of this approach to understand the psychological dynamics of adapting to technological advances.
Weinstein, Netta
2016-01-01
Theories regarding the influences of electronic games drive scientific study, popular debate, and public policy. The fractious interchanges among parents, pundits, and scholars hint at the rich phenomenological and psychological dynamics that underlie how people view digital technologies such as games. The current research applied Martin Heidegger’s concept of interpretive frameworks (Heidegger, 1987) and Robert Zajonc’s exposure-attitude hypothesis (Zajonc, 1968) to explore how attitudes towards technologies such as electronic games arise. Three studies drew on representative cohorts of American and British adults and evaluated how direct and indirect experiences with games shape how they are seen. Results indicated this approach was fruitful: negative attitudes and beliefs linking games to real-world violence were prominent among those with little direct exposure to electronic gaming contexts, whereas those who played games and reported doing so with their children tended to evaluate gaming more positively. Further findings indicated direct experience tended to inform the accuracy of beliefs about the effects of digital technology, as those who had played were more likely to believe that which is empirically known about game effects. Results are discussed with respect to ongoing debates regarding gaming and broader applications of this approach to understand the psychological dynamics of adapting to technological advances. PMID:27077016
Variations in Metformin Prescribing for Type 2 Diabetes.
Goldberg, Tiffany; Kroehl, Miranda E; Suddarth, Kathleen Heist; Trinkley, Katy E
2015-01-01
Reasons for suboptimal metformin prescribing are unclear, but may be due to perceived risk of lactic acidosis. The purpose of this study is to describe provider attitudes regarding metformin prescribing in various patient situations. An anonymous, electronic survey was distributed electronically to 76 health care providers across the nation. The 14-item survey contained demographic questions and questions related to prescribing of metformin for T2DM in various patient situations, including suboptimal glycemic control, alcohol use, history of lactic acidosis, and varying degrees of severity for certain health conditions, including renal and hepatic dysfunction, chronic obstructive pulmonary disease, and heart failure. There were a total of 100 respondents. For suboptimal glycemic control, most providers (75%) would increase metformin from 1500 to 2000 mg daily; however, 25% would add an alternate agent, such as a sulfonylurea (18%) or dipeptidyl peptidase-4 inhibitor (7%). Although 51% of providers would stop metformin based on serum creatinine thresholds, the remainder would rely on glomerular filtration rate thresholds of <60 mL/min (15%), <30 mL/min (33%), or <15 mL/min (1%) to determine when to stop metformin. For heart failure, 45% of providers would continue metformin as currently prescribed regardless of severity. Most providers would adjust metformin for varying severity of hepatic dysfunction (74%) and alcohol abuse (40%). Despite evidence supporting the cardiovascular benefits of metformin, provider attitudes toward prescribing metformin are suboptimal in certain patient situations and vary greatly by provider. © Copyright 2015 by the American Board of Family Medicine.
Gainey, Randy R; Payne, Brian K
2003-04-01
The notion that community support is critical for program success is a consistent theme in the literature on community-based corrections. Unfortunately, many citizens know very little about alternative sanctions, are misinformed about them, and do not view them favorably. At issue is whether information about alternative sanctions affects individuals' attitudes regarding them. To address this question, students in an upper division criminal justice course were surveyed before and after a presentation on electronic monitoring. Following the presentation, students were more likely to agree that electronic monitoring is punitive and that it meets several goals of the justice system. Implications for policy makers and educators are provided.
Attitudes toward Electronic Monitoring among Monitored Offenders and Criminal Justice Students.
ERIC Educational Resources Information Center
Payne, Brian K.; Gainey, Randy R.
1999-01-01
Examines what 180 students think about electronic monitoring and compares their perceptions to those of 29 electronically-monitored offenders. Results show that students were less supportive of electronic monitoring but when asked about what offenders have to give up, they viewed the sanction more punitively than did offenders. Implications…
Utilzing Networked Computer Workstations To Conduct Electronic Focus Groups.
ERIC Educational Resources Information Center
Lowery, Catherine; Franklin, Kathy K.
Researchers at the University of Arkansas at Little Rock conducted a study of faculty attitudes about the use of technology in the college classroom using electronic focus group sessions. This paper examines the electronic focus group data collection procedure. The electronic sessions were conducted in a decision-support center on campus with 13…
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.
Hamson-Utley, J Jordan; Martin, Scott; Walters, Jason
2008-01-01
Psychological skills are alleged to augment sport-injury rehabilitation; however, implementation of mental imagery within rehabilitation programs is limited. To examine attitudes of athletic trainers (ATs) and physical therapists (PTs) on the effectiveness of mental imagery, goal setting, and positive self-talk to improve rehabilitation adherence and recovery speed of injured athletes. The ATs and PTs were contacted via electronic or physical mailings to complete a single administration survey that measured their beliefs about the effectiveness of psychological skills for increasing adherence and recovery speed of injured athletes undergoing rehabilitation. Professional member databases of the National Athletic Trainers' Association and the American Physical Therapy Association. Of the 1000 ATs and 1000 PTs who were selected randomly, 309 ATs (age = 34.18 +/- 8.32 years, years in profession = 10.67 +/- 7.34) and 356 PTs (age = 38.58 +/- 7.51 years, years in profession = 13.18 +/- 6.17) responded. The Attitudes About Imagery (AAI) survey measures attitudes about psychological skills for enhancing adherence and recovery speed of injured athletes. The AAI includes demographic questions and 15 items on a 7-point Likert scale measuring attitudes about the effectiveness of mental imagery, self-talk, goal setting, and pain control on rehabilitation adherence and recovery speed of injured athletes. Test-retest reliability ranged from .60 to .84 and Cronbach alphas ranged from .65 to .90. We calculated 1-way analyses of variance to determine whether differences existed in attitudes as a result of the professionals' education, training experience, and interest. Mean differences were found on attitudes about effectiveness of psychological skills for those who reported formal training and those who reported interest in receiving formal training (P < .05). In addition, ATs held more positive attitudes than PTs on 9 of 15 AAI items (P < .05). Overall, ATs and PTs held positive attitudes on the effectiveness of psychological skills to augment the rehabilitation process. Clinical implications regarding the use of mental skills are discussed.
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 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.
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.
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.
State estimation for autopilot control of small unmanned aerial vehicles in windy conditions
NASA Astrophysics Data System (ADS)
Poorman, David Paul
The use of small unmanned aerial vehicles (UAVs) both in the military and civil realms is growing. This is largely due to the proliferation of inexpensive sensors and the increase in capability of small computers that has stemmed from the personal electronic device market. Methods for performing accurate state estimation for large scale aircraft have been well known and understood for decades, which usually involve a complex array of expensive high accuracy sensors. Performing accurate state estimation for small unmanned aircraft is a newer area of study and often involves adapting known state estimation methods to small UAVs. State estimation for small UAVs can be more difficult than state estimation for larger UAVs due to small UAVs employing limited sensor suites due to cost, and the fact that small UAVs are more susceptible to wind than large aircraft. The purpose of this research is to evaluate the ability of existing methods of state estimation for small UAVs to accurately capture the states of the aircraft that are necessary for autopilot control of the aircraft in a Dryden wind field. The research begins by showing which aircraft states are necessary for autopilot control in Dryden wind. Then two state estimation methods that employ only accelerometer, gyro, and GPS measurements are introduced. The first method uses assumptions on aircraft motion to directly solve for attitude information and smooth GPS data, while the second method integrates sensor data to propagate estimates between GPS measurements and then corrects those estimates with GPS information. The performance of both methods is analyzed with and without Dryden wind, in straight and level flight, in a coordinated turn, and in a wings level ascent. It is shown that in zero wind, the first method produces significant steady state attitude errors in both a coordinated turn and in a wings level ascent. In Dryden wind, it produces large noise on the estimates for its attitude states, and has a non-zero mean error that increases when gyro bias is increased. The second method is shown to not exhibit any steady state error in the tested scenarios that is inherent to its design. The second method can correct for attitude errors that arise from both integration error and gyro bias states, but it suffers from lack of attitude error observability. The attitude errors are shown to be more observable in wind, but increased integration error in wind outweighs the increase in attitude corrections that such increased observability brings, resulting in larger attitude errors in wind. Overall, this work highlights many technical deficiencies of both of these methods of state estimation that could be improved upon in the future to enhance state estimation for small UAVs in windy conditions.
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.
The effect of electronic cigarette advertising on intended use among college students.
Trumbo, Craig W; Kim, Se-Jin Sage
2015-07-01
. Aside from prohibiting health claims, there are presently no restrictions on electronic cigarette advertising in the U.S. Studies have shown college students have a positive view of e-cigarettes and use on campuses is increasing. The purpose of this study was to test if the appeal of e-cigarette advertisements and beliefs about the addictiveness of e-cigarettes may affect their uptake among college students. The study was framed within the Theory of Reasoned Action, which posits that behavioral intention can be understood in terms of social norms and attitudes toward a behavior. We also included variables capturing appeal of e-cigarette advertisements, belief that e-cigarettes are not as addictive as cigarettes, and tobacco use. Attitudes toward e-cigarettes, perceived norms concerning their use, beliefs that e-cigarettes are not as addictive as cigarettes, and positive appraisal of e-cigarette advertising videos were all hypothesized to be independently positively associated with intention to use an e-cigarette. Data were collected through a survey of students at a major U.S. university (participation rate 78%, N=296). Participants were exposed to three e-cigarette video advertisements in random order. In a regression analysis we found positive reaction to the ads and holding the belief that e-cigarettes are not as addictive were both independently associated with intention. Attitudes and norms were also associated but were controlled by inclusion of the other variables. These findings suggest that advertising may promote the uptake of e-cigarettes and may do so in addition to current smoking and alternate tobacco use status. Copyright © 2015 Elsevier Ltd. All rights reserved.
Ground station software for receiving and handling Irecin telemetry data
NASA Astrophysics Data System (ADS)
Ferrante, M.; Petrozzi, M.; Di Ciolo, L.; Ortenzi, A.; Troso, G
2004-11-01
The on board resources, needed to perform the mission tasks, are very limited in nano-satellites. This paper proposes a software system to receive, manage and process in Real Time the Telemetry data coming from IRECIN nanosatellite and transmit operator manual commands and operative procedures. During the receiving phase, it shows the IRECIN subsystem physical values, visualizes the IRECIN attitude, and performs other suitable functions. The IRECIN Ground Station program is in charge to exchange information between IRECIN and the Ground segment. It carries out, in real time during IRECIN transmission phase, IRECIN attitude drawing, sun direction drawing, power supply received from Sun, visualization of the telemetry data, visualization of Earth magnetic field and more other functions. The received data are memorized and interpreted by a module, parser, and distribute to the suitable modules. Moreover it allows sending manual and automatic commands. Manual commands are delivered by an operator, on the other hand, automatic commands are provided by pre-configured operative procedures. Operative procedures development is realized in a previous phase called configuration phase. This program is also in charge to carry out a test session by mean the scheduler and commanding modules allowing execution of specific tasks without operator control. A log module to memorize received and transmitted data is realized. A phase to analyze, filter and visualize in off line the collected data, called post analysis, is based on the data extraction form the log module. At the same time, the Ground Station Software can work in network allowing managing, receiving and sending data/commands from different sites. The proposed system constitutes the software of IRECIN Ground Station. IRECIN is a modular nanosatellite weighting less than 2 kg, constituted by sixteen external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Lithium-ions batteries are used. Attitude is determined by two three-axis magnetometers and the solar panels data. Control is provided by an active magnetic control system. The spacecraft will be spin- stabilized with the spin-axis normal to the orbit. All IRECIN electronic components are SMD technology in order to reduce weight and size. The realized Electronic board are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Develop Group
Jahanbakhsh, Maryam; Karimi, Saeed; Hassanzadeh, Akbar; Beigi, Maliheh
2017-01-01
Electronic medical record system (EMRS) is a valuable system for safe access to the patient's data and increases health care quality. Manpower is one of the requirements for EMRS, among which manager is the most important person in any hospital. Taking into account manager's positive attitude and good commitments, EMRS will be implemented successfully. As such, we decided to assess manager's attitude and commitment toward EMRS in Isfahan hospitals in the year of 2014. This article aimed to determine the hospital managers' attitude and commitment toward the implementation of EMRS. The present article is an applied analytic study. Research society consisted of the managers of all the hospitals in Isfahan that include hospitals affiliated to Isfahan University of Medical Sciences, private, and social security hospitals. This study was done in 2014. Data collection tools included a questionnaire for which reliability and validity were determined. Data were analyzed by means of SPSS 20. Average score for the managers' attitude toward EMRS in the city of Isfahan was 77.5 out of 100 and their average score for commitment was 74.7. Manager's attitude in social security hospitals was more positive than the private and governmental ones (83.3%). In addition, the amount of commitment by the managers in social security hospitals was higher than the same in private and governmental hospitals (86.6%). At present, managers' attitude and commitment in Isfahan hospitals toward EMRS are very high and social security hospitals show more readiness in this respect.
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.
Elewa, Hazem; Alkhiyami, Dania; Alsahan, Dima; Abdel-Aziz, Ahmed
2015-08-01
Pharmacists are expected to play an important role in applying pharmacogenomics discoveries to patient care. Despite the increased attention to genetic research in Qatar, clinicians' attitudes towards the application of pharmacogenomics are not yet explored. The aim of this study was to assess the awareness and attitude of pharmacists compared with doctors towards pharmacogenomics and its implications by submitting an electronic-based survey to all pharmacists and doctors currently working in a large medical corporation in Qatar. A cross-sectional survey instrument was developed based on literature review. Eligible participants were pharmacists and doctors currently practicing in Hamad Medical Corporation hospitals in Qatar. The survey comprised questions on demographic and professional characteristics. It also evaluated the awareness, attitudes and challenges towards pharmacogenomics and its application. We collected 202 surveys, 108 (53.2%) of which were pharmacists and the remaining 94 (46.5%) were doctors. The overall participants' mean total awareness score percentage was low (39% ± 22) and there were no difference between the mean score achieved by pharmacists and doctors. Pharmacists had significantly more positive attitudes than doctors towards: (i) taking the responsibility of applying pharmacogenomics to drug therapy selection, dosing and monitoring; (ii) perceiving a positive role of pharmacogenomics testing on the control of drug expenditure; and (iii) their willingness to participate in pharmacogenomics-related training sessions. Both pharmacists and doctors perceived lack of knowledge and guidelines as major challenges towards the application of pharmacogenomics in Qatar. Despite doctors' and pharmacists' low level of awareness towards pharmacogenomics, they both have positive attitudes towards the clinical implications of pharmacogenomics. Pharmacists are more motivated to learn about pharmacogenomics and are more willing to take initiatives in its clinical application and patient education. © 2015 John Wiley & Sons, Ltd.
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.
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.
Sanders-Jackson, Ashley; Tan, Andy S L; Yie, Kyeungyeun
2017-10-05
Certain tobacco companies use health-oriented descriptors (eg, 100% organic) on product packaging and advertising of combustible cigarettes or electronic cigarettes (e-cigarettes) that create a 'health halo' around smoking and vaping. Previous observational research suggests that such language may be associated with more favourable attitudes and reduced risk perceptions toward these brands compared with others. This study aimed to determine the effects of health-oriented descriptors on smokers' attitude toward the brand, perception of packaging information, comparative harm versus other brands and intention to purchase either combustible cigarettes or e-cigarettes. US adult smokers were randomly assigned to view either a health-oriented language package ('100% organic,' 'all natural' or 'no additives'), traditional marketing language package ('fine quality,' 'premium blend' or '100% original') or a no-language package of a combustible cigarette brand (Study 1, n=405) or an e-cigarette brand (Study 2, n=396) in an experimental design. Study 1: Participants in the health-oriented condition reported more favourable perceptions toward the package information, lower comparative harm and higher intention to purchase combustible cigarettes versus the no language control. In addition, participants in the health-oriented condition reported more positive attitude toward the brand and lower comparative harm versus the traditional marketing condition. Study 2: Compared with the traditional marketing condition, participants in the health-oriented condition reported greater intention to purchase Absolute e-cigarettes. There were no significant differences in attitude toward the brand, perception of packaging information and comparative harm versus other brands across conditions. The effect of health-oriented language was significant for combustible cigarettesand e-cigarette packages. Policies to restrict health-oriented language on cigarette and e-cigarette packaging are recommended. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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.
Linguistically Diverse Students' Attitudes towards Writing in English
ERIC Educational Resources Information Center
Bustamante, Analynn; Eom, Minhee
2017-01-01
This study investigated attitudes of linguistically diverse students towards writing in English in four different domains: general academic writing, writing in humanities, writing in science-related subjects (STEM), and writing in electronic communication. A total of 77 Hispanic bilingual/ELL adult students at an alternative high school in…
Zhao, Yu; Liu, Yide; Lai, Ivan K W; Zhang, Hongfeng; Zhang, Yi
2016-03-18
As one of the latest revolutions in networking technology, social networks allow users to keep connected and exchange information. Driven by the rapid wireless technology development and diffusion of mobile devices, social networks experienced a tremendous change based on mobile sensor computing. More and more mobile sensor network applications have appeared with the emergence of a huge amount of users. Therefore, an in-depth discussion on the human-computer interaction (HCI) issues of mobile sensor computing is required. The target of this study is to extend the discussions on HCI by examining the relationships of users' compound attitudes (i.e., affective attitudes, cognitive attitude), engagement and electronic word of mouth (eWOM) behaviors in the context of mobile sensor computing. A conceptual model is developed, based on which, 313 valid questionnaires are collected. The research discusses the level of impact on the eWOM of mobile sensor computing by considering user-technology issues, including the compound attitude and engagement, which can bring valuable discussions on the HCI of mobile sensor computing in further study. Besides, we find that user engagement plays a mediating role between the user's compound attitudes and eWOM. The research result can also help the mobile sensor computing industry to develop effective strategies and build strong consumer user-product (brand) relationships.
Zhao, Yu; Liu, Yide; Lai, Ivan K. W.; Zhang, Hongfeng; Zhang, Yi
2016-01-01
As one of the latest revolutions in networking technology, social networks allow users to keep connected and exchange information. Driven by the rapid wireless technology development and diffusion of mobile devices, social networks experienced a tremendous change based on mobile sensor computing. More and more mobile sensor network applications have appeared with the emergence of a huge amount of users. Therefore, an in-depth discussion on the human–computer interaction (HCI) issues of mobile sensor computing is required. The target of this study is to extend the discussions on HCI by examining the relationships of users’ compound attitudes (i.e., affective attitudes, cognitive attitude), engagement and electronic word of mouth (eWOM) behaviors in the context of mobile sensor computing. A conceptual model is developed, based on which, 313 valid questionnaires are collected. The research discusses the level of impact on the eWOM of mobile sensor computing by considering user-technology issues, including the compound attitude and engagement, which can bring valuable discussions on the HCI of mobile sensor computing in further study. Besides, we find that user engagement plays a mediating role between the user’s compound attitudes and eWOM. The research result can also help the mobile sensor computing industry to develop effective strategies and build strong consumer user—product (brand) relationships. PMID:26999155
Electronic Mentoring of LIS Research Utilizing BITNET: An ACRL Pilot Project.
ERIC Educational Resources Information Center
Gregory, Vicki L.
1992-01-01
Describes an ACRL (American College and Research Libraries) project that utilized the electronic conferencing facility of BITNET to provide a system of mentoring for academic librarians conducting research. Results of an electronic mail survey of participants that examined experience levels, attitudes, problems, and communication patterns are…
Health Risks Awareness of Electronic Waste Workers in the Informal Sector in Nigeria
Van Bodegom, Peter M.; Vijver, Martina G.
2017-01-01
Insight into the health risk awareness levels of e-waste workers is important as it may offer opportunities for better e-waste recycling management strategies to reduce the health effects of informal e-waste recycling. Therefore, this study assessed the knowledge, attitude, and practices associated with occupational health risk awareness of e-waste workers compared with a control group (butchers) in the informal sector in Nigeria. A cross-sectional study was used to assess health risk awareness of 279 e-waste workers (repairers and dismantlers) and 221 butchers from the informal sector in three locations in Nigeria in 2015. A questionnaire was used to obtain information on socio-demographic backgrounds, occupational history, knowledge, attitude, and work practices. The data was analysed using Analysis of Variance. The three job designations had significantly different knowledge, attitude, and practice mean scores (p = 0.000), with butchers consistently having the highest mean scores. Only 43% of e-waste workers could mention one or more Personal Protective Equipment needed for their job compared with 70% of the butchers. The health risk awareness level of the e-waste workers was significantly lower compared with their counterparts in the same informal sector. A positive correlation existed between the workers’ knowledge and their attitude and practice. Therefore, increasing the workers’ knowledge may decrease risky practices. PMID:28805712
2000-10-23
In the Space Station Processing Facility, a worker is surprised by the camera as she exits the U.S. Lab, Destiny. Inside the lab is the STS-98 crew, which is taking part in Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. The crew comprises Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-10-23
In the Space Station Processing Facility, workers in the foreground watch and wait while members of the STS-98 crew check out the U.S. Lab, Destiny in the background. The crew comprises Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins. They are taking part in Crew Equipment Interface Test activities, becoming familiar with equipment they will be handling during the mission. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-12-04
Inside Orbiter Processing Facility bay 3, Atlantis is ready for rollover to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-10-23
In the Space Station Processing Facility, members of the STS-98 crew check out components inside the U.S. Lab, Destiny, under the watchful eye of trainers. The crew comprises Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins. They are taking part in Crew Equipment Interface Test activities, becoming familiar with equipment they will be handling during the mission. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-10-23
Inside the U.S. Lab, Destiny, members of the STS-98 crew work with technicians (in the background) to learn more about the equipment in the module. They are taking part in Crew Equipment Interface Test activities. At left, back to camera, is Mission Specialist Marsha Ivins. Standing are Mission Specialists Thomas Jones (left) and Robert Curbeam (right). Other crew members not seen are Commander Ken Cockrell and Pilot Mark Polansky. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-10-23
In the Space Station Processing Facility, STS-98 Mission Specialist Marsha Ivins wields a tool on part of the U.S. Lab, Destiny. The crew is checking out equipment inside the lab as part of Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. Others in the crew are Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Thomas Jones. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-10-23
In the Space Station Processing Facility, STS-98 Mission Specialist Marsha Ivins maneuvers a part of the U.S. Lab, Destiny. The crew is checking out equipment inside the lab as part of Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. Others in the crew are Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Thomas Jones. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2001-01-02
KENNEDY SPACE CENTER, Fla. -- Under cloudy skies, Space Shuttle Atlantis inches its way to Launch Pad 39A from the Vehicle Assembly Building (right). The journey is a distance of just over 3 miles. The water in the foreground is part of Banana Creek. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
2001-01-03
KENNEDY SPACE CENTER, Fla. -- Space Shuttle Atlantis reaches its destination, Launch Pad 39A, for liftoff no earlier than Jan. 19 on mission STS-98. To its immediate left is the Fixed Service Structure, with its 80-foot-tall white lighting mast on top. Further to the left is the Rotating Service Structure, where the white payload canister is being lifted to the Payload Changeout Room. The payload for the mission is the U.S. Lab Destiny, a key element in the construction of the International Space Station. The lab has five system racks for experiments already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated
2000-10-23
In the Space Station Processing Facility, members of the STS-98 crew, sitting in front of the U.S. Lab, Destiny, listen to a trainer during Crew Equipment Interface Test (CEIT) activities. Seen, left to right, are Mission Specialist Thomas Jones, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Marsha Ivins (with camera). The CEIT allows a crew 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
2000-10-23
In the Space Station Processing Facility, workers at left watch while members of the STS-98 crew check out equipment inside the U.S. Lab, Destiny (at right). The crew comprises Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins. They are taking part in Crew Equipment Interface Test activities, becoming familiar with equipment they will be handling during the mission. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-12-04
Inside Orbiter Processing Facility bay 3, Atlantis is ready for rollover to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
STS-98 crew members take part in CEIT
NASA Technical Reports Server (NTRS)
2000-01-01
In the Space Station Processing Facility, a worker is surprised by the camera as she exits the U.S. Lab, Destiny. Inside the lab is the STS-98 crew, which is taking part in Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. The crew comprises Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001.
STS-98 crew members take part in CEIT
NASA Technical Reports Server (NTRS)
2000-01-01
In the Space Station Processing Facility, STS-98 Mission Specialist Marsha Ivins maneuvers a part of the U.S. Lab, Destiny. The crew is checking out equipment inside the lab as part of Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. Others in the crew are Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Thomas Jones. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001.
2000-11-18
KENNEDY SPACE CENTER, FLA. -- Some of the STS-98 crew look over the Canadian robotic arm in the payload bay of orbiter Atlantis, which is undergoing testing in the Orbiter Processing Facility bay 3. At right, pointing, is Mission Specialist Tom Jones. Second from right is Mission Specialist 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. -- Some of the STS-98 crew look over the Canadian robotic arm in the payload bay of orbiter Atlantis, which is undergoing testing in the Orbiter Processing Facility bay 3. At right, pointing, is Mission Specialist Tom Jones. Second from right is Mission Specialist 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
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.
Chih, Wen-Hai; Wang, Kai-Yu; Hsu, Li-Chun; Huang, Su-Chen
2013-09-01
Electronic word of mouth (eWOM) has been an important factor influencing consumer purchase decisions. Using the ABC model of attitude, this study proposes a model to explain how eWOM affects online discussion forums. Specifically, we propose that platform (Web site reputation and source credibility) and customer (obtaining buying-related information and social orientation through information) factors influence purchase intentions via perceived positive eWOM review credibility, as well as product and Web site attitudes in an online community context. A total of 353 online discussion forum users in an online community (Fashion Guide) in Taiwan were recruited, and structural equation modeling (SEM) was used to test the research hypotheses. The results indicate that Web site reputation, source credibility, obtaining buying-related information, and social orientation through information positively influence perceived positive eWOM review credibility. In turn, perceived positive eWOM review credibility directly influences purchase intentions and also indirectly influences purchase intentions via product and Web site attitudes. Finally, we discuss the theoretical and managerial implications of the findings.
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.
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.
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…
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.
The Policy Maker's Anguish: Regulating Personal Data Behavior Between Paradoxes and Dilemmas
NASA Astrophysics Data System (ADS)
Compañó, Ramón; Lusoli, Wainer
Regulators in Europe and elsewhere are paying great attention to identity, privacy and trust in online and converging environments. Appropriate regulation of identity in a ubiquitous information environment is seen as one of the major drivers of the future Internet economy. Regulation of personal identity data has come to the fore including mapping conducted on digital personhood by the OECD; work on human rights and profiling by the Council of Europe andmajor studies by the European Commission with regard to self-regulation in the privacy market, electronic identity technical interoperability and enhanced safety for young people. These domains overlap onto an increasingly complex model of regulation of individuals' identity management, online and offline. This chapter argues that policy makers struggle to deal with issues concerning electronic identity, due to the apparently irrational and unpredictable behavior of users when engaging in online interactions involving identity management. Building on empirical survey evidence from four EU countries, we examine the first aspect in detail - citizens' management of identity in a digital environment. We build on data from a large scale (n = 5,265) online survey of attitudes to electronic identity among young Europeans (France, Germany, Spain, UK) conducted in August 2008. The survey asked questions about perceptions and acceptance of risks, general motivations, attitudes and behaviors concerning electronic identity. Four behavioral paradoxes are identified in the analysis: a privacy paradox (to date well known), but also a control paradox, a responsibility paradox and an awareness paradox. The chapter then examines the paradoxes in relation of three main policy dilemmas framing the debate on digital identity. The paper concludes by arguing for an expanded identity debate spanning policy circles and the engineering community.
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.
NASA Technical Reports Server (NTRS)
Clement, W. F.
1976-01-01
The use which pilots make of a moving map display from en route through the terminal area and including the approach and go-around flight phases was investigated. The content and function of each of three primary STOLAND displays are reviewed from an operational point of view. The primary displays are the electronic attitude director indicator (EADI), the horizontal situation indicator (HSI), and the multifunction display (MFD). Manually controlled flight with both flight director guidance and raw situation data is examined in detail in a simulated flight experiment with emphasis on tracking reference flight plans and maintaining geographic orientation after missed approaches. Eye-point-of-regard and workload measurements, coupled with task performance measurements, pilot opinion ratings, and pilot comments are presented. The experimental program was designed to offer a systematic objective and subjective comparison of pilots' use of the moving map MFD in conjunction with the other displays.
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 health consequences of maquiladora work: women on the US-Mexican border.
Guendelman, S; Silberg, M J
1993-01-01
OBJECTIVES. As more US companies take jobs to Mexico, complaints are growing that the assembly plants (maquiladoras) exert adverse effects on workers' health. This study assessed the health of female electronic and garment maquiladora workers, comparing them with women employed in services and non-wage earners. METHODS. A survey was administered to 480 women living in Tijuana in 1990. The sample was stratified by occupation and length of employment. Functional impediments, nervousness, depression, and sense of control were used as outcome variables, controlling for other confounders. RESULTS. Despite working longer hours, receiving lower wages, and having less decision latitude and education, maquiladora workers were not worse off than service workers. Maquiladora workers reported similar incidences of depression and lack of control over life. Electronics workers, especially, had lower incidences of nervousness and functional impediments, after controlling for other confounders. Also, maquiladora work did not add an extra health burden compared with non-wage earners. CONCLUSIONS. The adverse effects of maquiladoras previously reported may have been exaggerated. Subjective factors, including negative attitudes toward economic adversity and work dissatisfaction, were stronger predictors of health than were objective indicators. PMID:8417604
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.
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,
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.
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.
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.
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.
Mission Performance of the GLAS Thermal Control System - 7 Years In Orbit
NASA Technical Reports Server (NTRS)
Grob, Eric W.
2010-01-01
ICESat (Ice, Cloud and land Elevation Satellite) was launched in 2003 carrying a single science instrument - the Geoscience Laser Altimeter System (GLAS). Its primary mission was to measure polar ice thickness. The GLAS thermal control architecture utilized propylene Loop Heat Pipe (LHP) technology to provide selectable and stable temperature control for the lasers and other electronics over a widely varying mission thermal environment. To minimize expected degradation of the radiators, Optical Solar Reflectors (OSRs) were used for both LHP radiators to minimize degradation caused by UV exposure in the various spacecraft attitudes necessary throughout the mission. Developed as a Class C mission, with selective redundancy, the thermal architecture was single st ring, except for temperature sensors used for heater control during normal operations. Although originally planned for continuous laser operations over the nominal three year science mission, laser anomalies limited operations to discrete measurement campaigns repeated throughout the year. For trending of the science data, these periods were selected to occur at approximately the same time each year, which resulted in operations during similar attitudes and beta angles. Despite the laser life issues, the LHPs have operated nearly continuously over this time, being non-operational for only brief periods. Using mission telemetry, this paper looks at the performance of the thermal subsystem during these periods and provides an assessment of radiator degradation over the mission lifetime.
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.
ERIC Educational Resources Information Center
Hubbard, Glenn T.; Kang, Jin-Ae; Crawford, Elizabeth Crisp
2016-01-01
National survey of college mass communication students (N = 247) analyzed attitudes on the teaching of print and electronic media skills, using journalism students as comparison group. Previous research had not explored strategic communication student responses to convergence. Found identity variables within public relations (PR) field related to…
ERIC Educational Resources Information Center
Belkin, Gary S.; Yusim, Anna; Anbarasan, Deepti; Bernstein, Carol Ann
2011-01-01
Objective: The authors surveyed Psychiatry Residency Training Directors' (RTDs') attitudes about the role and feasibility of international rotations during residency training. Method: A 21-question survey was electronically distributed that explored RTDs' beliefs about the value, use, and availability of international clinical and research…
Relationship of the Media to Attitudes toward People with Mental Illness.
ERIC Educational Resources Information Center
Granello, Darcy Haag; Pauley, Pamela S.; Carmichael, Ann
1999-01-01
Reports on results of Community Attitudes Toward Mentally Ill questionnaire given to undergraduates. Significant differences emerged on subscales based ranking of primary source of information about mental illness. Results do not imply causality but rather that electronic media is powerful mechanism for spreading the stigma of mental illness.…
ERIC Educational Resources Information Center
Tait, Glendon R.; Hodges, Brian D.
2009-01-01
Objective: The authors examined psychiatric residents' attitudes, perceived preparedness, experiences, and needs in end-of-life care education. They also examined how residents conceptualized good end-of-life care and dignity. Methods: The authors conducted an electronic survey of 116 psychiatric residents at the University of Toronto. The survey…
NASA Technical Reports Server (NTRS)
Glaab, Louis J.; Takallu, Mohammad A.
2002-01-01
An experimental investigation was conducted to study the effectiveness of Synthetic Vision Systems (SVS) flight displays as a means of eliminating Low Visibility Loss of Control (LVLOC) and Controlled Flight Into Terrain (CFIT) accidents by low time general aviation (GA) pilots. A series of basic maneuvers were performed by 18 subject pilots during transition from Visual Meteorological Conditions (VMC) to Instrument Meteorological Conditions (IMC), with continued flight into IMC, employing a fixed-based flight simulator. A total of three display concepts were employed for this evaluation. One display concept, referred to as the Attitude Indicator (AI) replicated instrumentation common in today's General Aviation (GA) aircraft. The second display concept, referred to as the Electronic Attitude Indicator (EAI), featured an enlarged attitude indicator that was more representative of a glass display that also included advanced flight symbology, such as a velocity vector. The third concept, referred to as the SVS display, was identical to the EAI except that computer-generated terrain imagery replaced the conventional blue-sky/brown-ground of the EAI. Pilot performance parameters, pilot control inputs and physiological data were recorded for post-test analysis. Situation awareness (SA) and qualitative pilot comments were obtained through questionnaires and free-form interviews administered immediately after the experimental session. Initial pilot performance data were obtained by instructor pilot observations. Physiological data (skin temperature, heart rate, and muscle flexure) were also recorded. Preliminary results indicate that far less errors were committed when using the EAI and SVS displays than when using conventional instruments. The specific data example examined in this report illustrates the benefit from SVS displays to avoid massive loss of SA conditions. All pilots acknowledged the enhanced situation awareness provided by the SVS display concept. Levels of pilot stress appear to be correlated with skin temperature measurements.
Jahanbakhsh, Maryam; Karimi, Saeed; Hassanzadeh, Akbar; Beigi, Maliheh
2017-01-01
INTRODUCTION: Electronic medical record system (EMRS) is a valuable system for safe access to the patient's data and increases health care quality. Manpower is one of the requirements for EMRS, among which manager is the most important person in any hospital. Taking into account manager's positive attitude and good commitments, EMRS will be implemented successfully. As such, we decided to assess manager's attitude and commitment toward EMRS in Isfahan hospitals in the year of 2014. AIM: This article aimed to determine the hospital managers’ attitude and commitment toward the implementation of EMRS. MATERIALS AND METHODS: The present article is an applied analytic study. Research society consisted of the managers of all the hospitals in Isfahan that include hospitals affiliated to Isfahan University of Medical Sciences, private, and social security hospitals. This study was done in 2014. Data collection tools included a questionnaire for which reliability and validity were determined. Data were analyzed by means of SPSS 20. RESULTS: Average score for the managers’ attitude toward EMRS in the city of Isfahan was 77.5 out of 100 and their average score for commitment was 74.7. Manager's attitude in social security hospitals was more positive than the private and governmental ones (83.3%). In addition, the amount of commitment by the managers in social security hospitals was higher than the same in private and governmental hospitals (86.6%). CONCLUSION: At present, managers’ attitude and commitment in Isfahan hospitals toward EMRS are very high and social security hospitals show more readiness in this respect. PMID:28584837
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.
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…
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.
Security Implications of Electronic Commerce: A Survey of Consumers and Businesses.
ERIC Educational Resources Information Center
Furnell, S. M.; Karweni, T.
1999-01-01
Examines general requirement for security technologies that provide a basis for trust in the electronic commerce environment. Discusses the results of two surveys that included general Internet users who are potential customers as well as commercial businesses, that considered attitudes to electronic commerce in general and options relating to…
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
NASA Technical Reports Server (NTRS)
Kimball, G., Jr.
1980-01-01
A simulator comparison of the velocity vector control wheel steering (VCWS) system and a decoupled longitudinal control system is presented. The piloting task was to use the electronic attitude direction indicator (EADI) to capture and maintain a 3 degree glide slope in the presence of wind shear and to complete the landing using the perspective runway included on the EADI. The decoupled control system used constant prefilter and feedback gains to provide steady state decoupling of flight path angle, pitch angle, and forward velocity. The decoupled control system improved the pilots' ability to control airspeed and flight path angle during the final stages of an approach made in severe wind shear. The system also improved their ability to complete safe landings. The pilots preferred the decoupled control system in severe winds and, on a pilot rating scale, rated the approach and landing task with the decoupled control system as much as 3 to 4 increments better than use of the VCWS system.
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.
Highly miniaturized FEEP propulsion system (NanoFEEP) for attitude and orbit control of CubeSats
NASA Astrophysics Data System (ADS)
Bock, Daniel; Tajmar, Martin
2018-03-01
A highly miniaturized Field Emission Electric Propulsion (FEEP) system is currently under development at TU Dresden, called NanoFEEP [1]. The highly miniaturized thruster heads are very compact and have a volume of less than 3 cm3 and a weight of less than 6 g each. One thruster is able to generate continuous thrust of up to 8 μN with short term peaks of up to 22 μN. The very compact design and low power consumption (heating power demand between 50 and 150 mW) are achieved by using Gallium as metal propellant with its low melting point of approximately 30 °C. This makes it possible to implement an electric propulsion system consisting of four thruster heads, two neutralizers and the necessary electronics on a 1U CubeSat with its strong limitation in space, weight and available power. Even formation flying of 1U CubeSats using an electric propulsion system is possible with this system, which is shown by the example of a currently planned cooperation project between Wuerzburg University, Zentrum fuer Telematik and TU Dresden. It is planned to use the NanoFEEP electric propulsion system on the UWE (University Wuerzburg Experimental) 1U CubeSat platform [2] to demonstrate orbit and two axis attitude control with our electric propulsion system NanoFEEP. We present the latest performance characteristics of the NanoFEEP thrusters and the highly miniaturized electronics. Additionally, the concept and the current status of a novel cold neutralizer chip using Carbon Nano Tubes (CNTs) is 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.
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...
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.
Sukums, Felix; Mensah, Nathan; Mpembeni, Rose; Kaltschmidt, Jens; Haefeli, Walter E.; Blank, Antje
2014-01-01
Background The QUALMAT (Quality of Maternal and Prenatal Care: Bridging the Know-do Gap) project has introduced an electronic clinical decision support system (CDSS) for pre-natal and maternal care services in rural primary health facilities in Burkina Faso, Ghana, and Tanzania. Objective To report an assessment of health providers’ computer knowledge, experience, and attitudes prior to the implementation of the QUALMAT electronic CDSS. Design A cross-sectional study was conducted with providers in 24 QUALMAT project sites. Information was collected using structured questionnaires. Chi-squared tests and one-way ANOVA describe the association between computer knowledge, attitudes, and other factors. Semi-structured interviews and focus groups were conducted to gain further insights. Results A total of 108 providers responded, 63% were from Tanzania and 37% from Ghana. The mean age was 37.6 years, and 79% were female. Only 40% had ever used computers, and 29% had prior computer training. About 80% were computer illiterate or beginners. Educational level, age, and years of work experience were significantly associated with computer knowledge (p<0.01). Most (95.3%) had positive attitudes towards computers – average score (±SD) of 37.2 (±4.9). Females had significantly lower scores than males. Interviews and group discussions showed that although most were lacking computer knowledge and experience, they were optimistic about overcoming challenges associated with the introduction of computers in their workplace. Conclusions Given the low levels of computer knowledge among rural health workers in Africa, it is important to provide adequate training and support to ensure the successful uptake of electronic CDSSs in these settings. The positive attitudes to computers found in this study underscore that also rural care providers are ready to use such technology. PMID:25361721
Sukums, Felix; Mensah, Nathan; Mpembeni, Rose; Kaltschmidt, Jens; Haefeli, Walter E; Blank, Antje
2014-01-01
The QUALMAT (Quality of Maternal and Prenatal Care: Bridging the Know-do Gap) project has introduced an electronic clinical decision support system (CDSS) for pre-natal and maternal care services in rural primary health facilities in Burkina Faso, Ghana, and Tanzania. To report an assessment of health providers' computer knowledge, experience, and attitudes prior to the implementation of the QUALMAT electronic CDSS. A cross-sectional study was conducted with providers in 24 QUALMAT project sites. Information was collected using structured questionnaires. Chi-squared tests and one-way ANOVA describe the association between computer knowledge, attitudes, and other factors. Semi-structured interviews and focus groups were conducted to gain further insights. A total of 108 providers responded, 63% were from Tanzania and 37% from Ghana. The mean age was 37.6 years, and 79% were female. Only 40% had ever used computers, and 29% had prior computer training. About 80% were computer illiterate or beginners. Educational level, age, and years of work experience were significantly associated with computer knowledge (p<0.01). Most (95.3%) had positive attitudes towards computers - average score (±SD) of 37.2 (±4.9). Females had significantly lower scores than males. Interviews and group discussions showed that although most were lacking computer knowledge and experience, they were optimistic about overcoming challenges associated with the introduction of computers in their workplace. Given the low levels of computer knowledge among rural health workers in Africa, it is important to provide adequate training and support to ensure the successful uptake of electronic CDSSs in these settings. The positive attitudes to computers found in this study underscore that also rural care providers are ready to use such technology.
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.
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.
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.
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.
GRODY - GAMMA RAY OBSERVATORY DYNAMICS SIMULATOR IN ADA
NASA Technical Reports Server (NTRS)
Stark, M.
1994-01-01
Analysts use a dynamics simulator to test the attitude control system algorithms used by a satellite. The simulator must simulate the hardware, dynamics, and environment of the particular spacecraft and provide user services which enable the analyst to conduct experiments. Researchers at Goddard's Flight Dynamics Division developed GRODY alongside GROSS (GSC-13147), a FORTRAN simulator which performs the same functions, in a case study to assess the feasibility and effectiveness of the Ada programming language for flight dynamics software development. They used popular object-oriented design techniques to link the simulator's design with its function. GRODY is designed for analysts familiar with spacecraft attitude analysis. The program supports maneuver planning as well as analytical testing and evaluation of the attitude determination and control system used on board the Gamma Ray Observatory (GRO) satellite. GRODY simulates the GRO on-board computer and Control Processor Electronics. The analyst/user sets up and controls the simulation. GRODY allows the analyst to check and update parameter values and ground commands, obtain simulation status displays, interrupt the simulation, analyze previous runs, and obtain printed output of simulation runs. The video terminal screen display allows visibility of command sequences, full-screen display and modification of parameters using input fields, and verification of all input data. Data input available for modification includes alignment and performance parameters for all attitude hardware, simulation control parameters which determine simulation scheduling and simulator output, initial conditions, and on-board computer commands. GRODY generates eight types of output: simulation results data set, analysis report, parameter report, simulation report, status display, plots, diagnostic output (which helps the user trace any problems that have occurred during a simulation), and a permanent log of all runs and errors. The analyst can send results output in graphical or tabular form to a terminal, disk, or hardcopy device, and can choose to have any or all items plotted against time or against each other. Goddard researchers developed GRODY on a VAX 8600 running VMS version 4.0. For near real time performance, GRODY requires a VAX at least as powerful as a model 8600 running VMS 4.0 or a later version. To use GRODY, the VAX needs an Ada Compilation System (ACS), Code Management System (CMS), and 1200K memory. GRODY is written in Ada and FORTRAN.
Haddad, Mark; Pinfold, Vanessa; Ford, Tamsin; Walsh, Brendan; Tylee, Andre
2018-07-01
Mental health problems in children and young people are a vital public health issue. Only 25% of British school children with diagnosed mental health problems have specialist mental health services contact; front-line staff such as school nurses play a vital role in identifying and managing these problems, and accessing additional services for children, but there appears limited specific training and support for this aspect of their role. To evaluate the effectiveness of a bespoke short training programme, which incorporated interactive and didactic teaching with printed and electronic resources. Hypothesized outcomes were improvements in school nurses' knowledge, attitudes, and recognition skills for depression. A cluster-randomised controlled trial. 146 school nurses from 13 Primary Care Trusts (PCTs) in London were randomly allocated to receive the training programme. School nurses from 7 PCTs (n = 81) were randomly allocated to receive the training intervention and from 6 PCTs (n = 65) for waiting list control. Depression detection was measured by response to vignettes, attitudes measured with the Depression Attitude Questionnaire, and knowledge by the QUEST knowledge measure. These outcomes were measured at baseline and (following training) 3 months and nine months later, after which nurses in the control group received the training programme. At 3 months, 115 nurses completed outcome measures. Training was associated with significant improvements in the specificity of depression judgements (52.0% for the intervention group and 47.2% for the control group, P = 0.039), and there was a non-significant increase in sensitivity (64.5% compared to 61.5% P = 0.25). Nurses' knowledge about depression improved (standardised mean difference = 0.97 [95% CI 0.58 to 1.35], P < 0.001); and confidence about their professional role in relation to depression increased. There was also a significant change in optimism about depression outcomes, but no change in tendency to defer depression management to specialists. At 9-month follow-up, improved specificity in depression identification and improved knowledge were maintained. This school nurse development programme, designed to convey best practice for the identification and care of depression, delivered significant improvements in some aspects of depression recognition and understanding, and was associated with increased confidence in working with young people experiencing mental health problems. Copyright © 2018 Elsevier Ltd. All rights reserved.
Symbology requirements in head-up and head-down displays for helicopters in NOE flight
NASA Astrophysics Data System (ADS)
Haidn, Hermann; Odendahl, Goetz
1993-12-01
In modern warfare scenarios military helicopters have to be able to operate in NoE envelopes under all meteorological conditions. Under daytime good weather conditions this poses no problem for well-trained aircrews. In nighttime or bad weather conditions however the use of electronic sensors like IIT or TI is necessary. The aircrew use these devices for obstacle detection and avoidance and flight attitude perception. Flight below tree top level is only feasible when both of these tasks can be accomplished safely throughout the whole flight. For this reason the pilots must fly visual at all times. Relying on instruments for flight attitude control when flying between the trees would surely result in the striking of obstacles. These facts and the necessity for the aircrew to view greater azimuth angles than fixed wing pilots imply differing equipment and symbology packages for the two aircraft species. As a matter of fact only helmet mounted displays are really useful for helicopter flight control symbology. The following are results of experience from a number of trials with symbology in helicopters in low level flight down to 10 feet at night with IITs.
True-sky demonstration of an autonomous star tracker
NASA Astrophysics Data System (ADS)
van Bezooijen, Roelof W.
1994-07-01
An autonomous star tracker (AST) is basically a `star field in, attitude out' device capable of determining its attitude without requiring any a priori attitude knowledge. In addition to this attitude acquisition capability, an AST can perform attitude updates autonomously and is able to provide its attitude `continuously' while tracking a star field. The Lockheed Palo Alto Research Laboratory is developing a reliable, low-cost, miniature AST that has a one arcsec overall accuracy, weighs less than 1.5 kg, consumes less than 7 watts of power, and is sufficiently sensitive to be used at all sky locations. The device performs attitude acquisition in a fraction of a second and outputs its attitude at a 10 Hz rate when operating in its tracking mode. Besides providing the functionality needed for future advanced attitude control and navigation systems, an AST also improves spacecraft reliability, mass, power, cost, and operating expenses. The AST comprises a-thermalized, refractive optics, a frame-transfer CCD with a sensitive area of 1024 by 1024 pixels, camera electronics implemented with application- specific integrated circuits, a compact single board computer with a radiation hard 32 bit RISC processor, and an all-sky guide star database. Star identification is performed by a memory- efficient and highly robust algorithm that finds the largest group of observed stars matching a group of guide stars. An important milestone has recently been achieved with the validation of the attitude acquisition capability through correct and rapid identification of all 704 true-sky star fields obtained at the Lick Observatory, using an uncalibrated prototype AST with a 512 by 1024 pixel frame-transfer CCD and a 50 mm f/1.2 lens that provided an effective 6.5 by 13.2 degree field of view. The overlapping fields cover 47% of the sky, including both rich and sparse areas. The paper contains a description of the AST, a summary of the functions enabled or improved by the device, an overview of the identification algorithm, results obtained with a realistic simulation program, a description of the true-sky star field identification method and a presentation of the results obtained. The AST tolerates the presence of bright objects as was demonstrated by a field that included Jupiter.
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.
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.
Teacher Electronic Portfolio and Its Relation to EFL Student Teacher Performance and Attitude
ERIC Educational Resources Information Center
Alshawi, Areej T.; Alshumaimeri, Yousif A.
2017-01-01
E-portfolio is a promising approach to develop teachers into reflective practitioners who show that they can adapt to new technologies, new criteria, and new environments. The current research explored the quality of EFL student teachers' e-portfolios and their attitudes towards using them. The research was conducted on 30 EFL female student…
ERIC Educational Resources Information Center
Tosa, Sachiko; Martin, Fred
2010-01-01
This study examined how a professional development program which incorporates the use of electronic data-loggers could impact on science teachers' attitudes towards inquiry-based teaching. The participants were 28 science or technology teachers who attended workshops offered in the United States and Japan. The professional development program…
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
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.
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.
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.
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.
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.
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.
2000-12-04
Viewed from inside Orbiter Processing Facility bay 3, Atlantis is ready for rollover to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis rolls away from the Orbiter Processing Facility bay 3 (in the background) to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis rolls toward the open door of the Vehicle Assembly Building after leaving the Orbiter Processing Facility bay 3. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis rolls toward the open door of the Vehicle Assembly Building after leaving the Orbiter Processing Facility bay 3. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis rolls out of the Orbiter Processing Facility bay 3 on its transporter. It is being transferred to the Vehicle Assembly Building where it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
Viewed from inside Orbiter Processing Facility bay 3, Atlantis is ready for rollover to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-10-23
In the Space Station Processing Facility, STS-98 Mission Specialist Thomas Jones works on a part of the U.S. Lab, Destiny. Watching at right is Pilot Mark Polansky. Jones and Polansky, along with other crew members, are taking part in Crew Equipment Interface Test activities to become familiar with equipment they will be handling during the mission. Others in the crew are Commander Ken Cockrell and Mission Specialists Robert Curbeam and Marsha Ivins. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
2000-12-04
The orbiter Atlantis, on its transporter, heads into the turn toward the Vehicle Assembly Building, in the background. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis rolls away from the Orbiter Processing Facility bay 3 (in the background) to the Vehicle Assembly Building. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2000-12-04
The orbiter Atlantis, on its transporter, heads into the turn toward the Vehicle Assembly Building, in the background. In the VAB it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
2001-01-03
STS-98 Pilot Mark Polansky is pleased to arrive at KSC’s Shuttle Landing Facility for Terminal Countdown Test Activities. In preparation for the Jan. 19 launch, he and the rest of the crew Commander Ken Cockrell and Mission Specialists Robert Curbeam, Thomas Jones and Marsha Ivins will be training in emergency procedures from the pad, checking the payload and taking part in a simulated countdown. The payload for the mission is the U.S. Lab Destiny, a key element in the construction of the International Space Station. The lab has five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. STS-98 is the seventh construction flight to the ISS.
2000-12-04
The orbiter Atlantis rolls out of the Orbiter Processing Facility bay 3 on its transporter. It is being transferred to the Vehicle Assembly Building where it will be raised to vertical and lifted up and into high bay 3 for stacking with its external tank and solid rocket boosters. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have 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. Atlantis is scheduled for launch on Jan. 18, 2001, at 2:44 a.m. EST, with a crew of five
STS-98 Atlantis rolls out to Launch Pad 39A
NASA Technical Reports Server (NTRS)
2001-01-01
KENNEDY SPACE CENTER, Fla. -- Under cloudy skies, Space Shuttle Atlantis inches its way to Launch Pad 39A from the Vehicle Assembly Building (right). The journey is a distance of just over 3 miles. The water in the foreground is part of Banana Creek. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station. The orbiter will carry in its payload bay the U.S. Laboratory, named Destiny, that will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five.
STS-98 crew members take part in CEIT
NASA Technical Reports Server (NTRS)
2000-01-01
Inside the U.S. Lab, Destiny, members of the STS-98 crew work with technicians (in the background) to learn more about the equipment in the module. They are taking part in Crew Equipment Interface Test activities. At left, back to camera, is Mission Specialist Marsha Ivins. Standing are Mission Specialists Thomas Jones (left) and Robert Curbeam (right). Other crew members not seen are Commander Ken Cockrell and Pilot Mark Polansky. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001.
STS-98 crew members take part in CEIT
NASA Technical Reports Server (NTRS)
2000-01-01
STS-98 Mission Specialist Robert Curbeam (right) raises his arms as he checks out equipment inside the U.S. Lab, Destiny. At left of center is Mission Specialist Marsha Ivins. Curbeam and Ivins, along with other crew members, are taking part in Crew Equipment Interface Test activities becoming familiar with equipment they will be handling during the mission. Others in the crew are Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialist Thomas Jones. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001.
2000-10-23
In the Space Station Processing Facility, members of the STS-98 crew check out equipment in the U.S. Lab, Destiny, with the help of workers. In the background, looking over her shoulder, is Mission Specialist Marsha Ivins. Others in the crew are Commander Ken Cockrell, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Thomas Jones. The crew is taking part in Crew Equipment Interface Test activities, becoming familiar with equipment it will be handling during the mission. The mission will be transporting the Lab to the International Space Station with five system racks already installed inside of the module. With delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. The STS-98 launch is scheduled for Jan. 18, 2001
STS-98 crew members take part in CEIT
NASA Technical Reports Server (NTRS)
2000-01-01
In the Space Station Processing Facility, members of the STS-98 crew, sitting in front of the U.S. Lab, Destiny, listen to a trainer during Crew Equipment Interface Test (CEIT) activities. Seen, left to right, are Mission Specialist Thomas Jones, Pilot Mark Polansky and Mission Specialists Robert Curbeam and Marsha Ivins (with camera). The CEIT allows a crew 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.
Environment induced anomalies on the TDRS and the role of spacecraft charging
NASA Technical Reports Server (NTRS)
Garrett, H. B.; Whittlesey, A.; Daughtridge, S.
1990-01-01
The NASA Tracking and Data Relay Satellites (TDRS) have experienced several classes of anomalies that appear to be related to the natural environment. The most serious of these have been anomalies in the Attitude Control System control processor electronics which resulted in check sum errors that were ultimately traced to high-energy, particle-induced single event upsets in the RAM memory. Three other types of anomalies on TDRS have also been correlated with environmental effects. This paper briefly documents the occurrences of these anomalies and describes the nature of each. These events are correlated with various environmental factors. For all cases, there appears to be a causal relationship between spacecraft charging events and the engineering anomalies.
2001-01-03
KENNEDY SPACE CENTER, Fla. -- Bright morning sun shines on Space Shuttle Atlantis as it sits on Launch Pad 39A. In front of the wings, on either side of the orbiter are tail service masts, which support the fluid, gas and electrical requirements of the orbiter’s liquid oxygen and liquid hydrogen aft T-0 umbilicals. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab has five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five
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.
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.
NASA Technical Reports Server (NTRS)
Rust, David M.
1987-01-01
The Solar Maximum Mission (SMM), designed to study the solar activity, was launched on February 14, 1980, just before the 1980 peak of sunspot and flare activity. The seven instruments aboard the SMM, information received by each of the instruments, and the performance of these instruments are described, together with the repair mission carried out to replace the attitude control module and the defective electronics in the satellite's observatory. The highlights of the scientific results obtained by the SMM mission and the new discoveries made are discussed, with special attention given to the flare loops, flare loop interactions, and the mass ejection events recorded.
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…
de Lugt-Lustig, Kersti H M E; Vanobbergen, Jacques N O; van der Putten, Gert-Jan; De Visschere, Luc M J; Schols, Jos M G A; de Baat, Cees
2014-02-01
To systematically review the literature on the effect of providing oral healthcare education to care home nurses on their oral healthcare knowledge and attitude and their oral hygiene care skills. A literature search was obtained for relevant articles on oral healthcare education of nurses in care homes, using five electronic retrieval systems and databases. The search was limited to human studies, articles published in English and articles published during the period January 1990 to December 2011. The methodological quality of an article was assessed on the basis of criteria published by the Cochrane Collaboration. For articles not meeting all methodological quality criteria, relevance criteria were used to determine how much scientific evidence could be assigned to the study findings. In accordance with the methodological quality criteria, two randomized controlled trials were included. Additionally, four studies were included after determining the scientific evidence of the study findings. The studies included revealed some scientific evidence and indications that an oral healthcare education programme for care home nurses may improve the nurses' oral healthcare knowledge and attitude. Any effect of oral healthcare education to care home nurses' oral hygiene care skills could not be determined. Oral healthcare education may have a positive effect on care home nurses' oral healthcare knowledge and attitude and on care home residents' oral hygiene, whereas any effect on care home nurses' oral hygiene care skills could not be found. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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.
Leblanc, Genevieve; Gagnon, Marie-Pierre; Sanderson, Duncan
2012-09-01
A provincial electronic health record is being developed in the Province of Quebec (and in all other provinces in Canada), and authorities hope that it will enable a safer and more efficient healthcare system for citizens. However, the expected benefits can occur only if healthcare professionals, including nurses, adopt this technology. Although attention to the use of the electronic health record by nurses is growing, better understanding of nurses' intention to use an electronic health record is needed and could help managers to better plan its implementation. This study examined the factors that influence primary care nurses' intention to adopt the provincial electronic health record, since intention influences electronic health record use and implementation success. Using a modified version of Ajzen's Theory of Planned Theory of Planned Behavior, a questionnaire was developed and pretested. Questionnaires were distributed to 199 primary care nurses. Multiple hierarchical regression indicated that the Theory of Planned Behavior variables explained 58% of the variance in nurses' intention to adopt an electronic health record. The strong intention to adopt the electronic health record is mainly determined by perceived behavioral control, normative beliefs, and attitudes. The implications of the study are that healthcare managers could facilitate adoption of an electronic health record by strengthening nurses' intention to adopt the electronic health record, which in turn can be influenced through interventions oriented toward the belief that using an electronic health record will improve the quality of patient care.
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.
Gupta, Adyya; Smithers, Lisa G; Harford, Jane; Merlin, Tracy; Braunack-Mayer, Annette
2018-07-01
Efforts to reduce sugar intake levels have been primarily limited to increasing knowledge and changing attitudes. We conducted a systematic review to (1) identify factors influencing adults' knowledge and attitudes about sugar, and (2) determine if there is an association between knowledge and attitudes about sugar and sugar intake. We searched 15 electronic databases from inception to December 2016 for English language publications including adults with relevant exposure and outcome measures. Findings were summarised meta-narratively. Of 3287 studies, 22 studies (14 for objective one and 8 for objective two) were included. Individual (liking of sugary food), interpersonal (attitudes of peers) and environmental factors (media, health professionals and food labelling) influenced adults' knowledge and attitudes about sugar, at least to some extent. Overall, quality of the studies included in our review was weak, and evidence for the application of the Knowledge-Attitude-Behavior model for understanding sugar intake is limited. Protocol registered in the PROSPERO International prospective register of systematic reviews (registration number CRD42015027540). Copyright © 2018 Elsevier Ltd. All rights reserved.
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.
NASA Astrophysics Data System (ADS)
Javidi, Giti
2005-07-01
This study was designed to investigate an alternative to the use of traditional physical laboratory activities in a communication systems course. Specifically, this study examined whether as an alternative, computer simulation is as effective as physical laboratory activities in teaching college-level electronics engineering education students about the concepts of signal transmission, modulation and demodulation. Eighty undergraduate engineering students participated in the study, which was conducted at a southeastern four-year university. The students were randomly assigned to two groups. The groups were compared on understanding the concepts, remembering the concepts, completion time of the lab experiments and perception toward the laboratory experiments. The physical group's (n = 40) treatment was to conduct laboratory experiments in a physical laboratory. The students in this group used equipment in a controlled electronics laboratory. The Simulation group's (n = 40) treatment was to conduct similar experiments in a PC laboratory. The students in this group used a simulation program in a controlled PC lab. At the completion of the treatment, scores on a validated conceptual test were collected once after the treatment and again three weeks after the treatment. Attitude surveys and qualitative study were administered at the completion of the treatment. The findings revealed significant differences, in favor of the simulation group, between the two groups on both the conceptual post-test and the follow-up test. The findings also revealed significant correlation between simulation groups' attitude toward the simulation program and their post-test scores. Moreover, there was a significant difference between the two groups on their attitude toward their laboratory experience in favor of the simulation group. In addition, there was significant difference between the two groups on their lab completion time in favor of the simulation group. At the same time, the qualitative research has uncovered several issues not explored by the quantitative research. It was concluded that incorporating the recommendations acquired from the qualitative research, especially elements of incorporating hardware experience to avoid lack of hands-on skills, into the laboratory pedagogy should help improve students' experience regardless of the environment in which the laboratory is conducted.
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
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)
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.
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.
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.
Educational games for health professionals.
Akl, E A; Sackett, K; Pretorius, R; Erdley, S; Bhoopathi, P S; Mustafa, R; Schünemann, H J
2008-01-23
The use of games as an educational strategy has the potential to improve health professionals' performance (e.g. adherence to standards of care) through improving their knowledge, skills and attitudes. The objective was to assess the effect of educational games on health professionals' performance, knowledge, skills, attitude and satisfaction, and on patient outcomes. We used a comprehensive search strategy including an electronic search of the following databases: DARE, EPOC register, CENTRAL, MEDLINE, EMBASE, CINAHL, AMED, ERIC, and Dissertation Abstracts Online (search date: January 2007). We also screened the reference list of included studies and relevant reviews, contact authors of relevant papers and reviews, and searched ISI Web of Science for papers citing studies included in the review We included randomized controlled trials (RCT), controlled clinical trials (CCT), controlled before and after (CBA) and interrupted time-series analysis (ITS). Study participants were qualified health professionals or in postgraduate training. The intervention was an educational game with "a form of competitive activity or sport played according to rules". Using a standardized data form we extracted data on methodological quality, participants, interventions and outcomes of interest that included patient outcomes, professional behaviour (process of care outcomes), and professional's knowledge, skills, attitude and satisfaction. The search strategy identified 1156 citations. Out of 55 potentially eligible citations, we included one RCT. The methodological quality was fair. The game, used as a reinforcement technique, was based on the television game show "Family Feud" and focused on infection control. The study did not assess any patient or process of care outcomes. The group that was randomized to the game had statistically higher scores on the knowledge test (P = 0.02). The findings of this systematic review do not confirm nor refute the utility of games as a teaching strategy for health professionals. There is a need for additional high-quality research to explore the impact of educational games on patient and performance outcomes.
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.
ERIC Educational Resources Information Center
Torres, Carlos A.
2011-01-01
This study investigated college students' attitudes toward and intentions to use personal health portals (PHPs) for managing their personal health information using a survey method. The study also aimed to examine the roles electronic Personal Health Information Management (PHIM) anxiety and apathy play in influencing students' attitudes toward…
The Attitudes and Opinions of Tutees and Tutors Towards Using Cross-Age Online Tutoring
ERIC Educational Resources Information Center
Almassaad, Ahmad; Alotaibi, Khaled
2012-01-01
The research aims to identify the attitudes and opinions of tutees and tutors at King Saud University towards using cross-age online tutoring. An electronic survey and interviews were used to collect the data required for this study. A descriptive analysis was used as a research methodology. Thirty participants in this research were asked to…
NASA Technical Reports Server (NTRS)
1982-01-01
Research issues in the area of electromagnetic measurements and signal handling of remotely sensed data are identified. The following seven issues are discussed; platform/sensor system position and velocity, platform/sensor attitudes and attitude rates, optics and antennas, detectors and associated electronics, sensor calibration, signal handling, and system design.
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.
Cross-Cultural Communication Patterns in Computer Mediated Communication
ERIC Educational Resources Information Center
Panina, Daria; Kroumova, Maya
2015-01-01
There are important cultural differences in attitudes towards and use of electronic text communication. Consistent with Hall's high-context/low-context conceptualization of culture, electronic inter-cultural communication, just as verbal inter-cultural communication, is affected by the culturally-specific assumptions and preferences of message…
Patient Perceptions of Electronic Health Records
ERIC Educational Resources Information Center
Lulejian, Armine
2011-01-01
Research objective. Electronic Health Records (EHR) are expected to transform the way medicine is delivered with patients/consumers being the intended beneficiaries. However, little is known regarding patient knowledge and attitudes about EHRs. This study examined patient perceptions about EHR. Study design. Surveys were administered following…
Fass, Jennifer A; Hardigan, Patrick C
2011-01-01
As of May 23, 2011, 35 states had an operational prescription drug monitoring program (PDMP), and 13 additional states, including Florida in 2009, had passed legislation to implement a PDMP. PDMPs, electronic databases that collect and track designated data on controlled substances and other commonly abused medications, are intended to serve as a tool for health care practitioners when prescribing and dispensing controlled substances to reduce drug abuse and diversion. In an analysis of 1,268 drug-caused deaths from January through June 2010 in Florida, the top 3 prescription drugs included the controlled substances oxycodone (56%), alprazolam (35%), and methadone (26%), all of which would be subject to reporting in Florida's PDMP when implemented. Because pharmacists are the health care professionals most affected by PDMP reporting requirements, evaluating their attitudes about PDMP implementation is important. To assess Florida pharmacists' attitudes toward implementing a PDMP in the state. This was a cross-sectional study conducted in Florida between February 2010 and June 2010 prior to the implementation of the proposed PDMP. A random sample of 5,000 of approximately 26,000 pharmacists licensed in Florida was invited to participate in a voluntary and anonymous 10-question self-administered mail survey of which 4 survey items assessed pharmacists' attitudes towards implementing a PDMP in the state. Of the 5,000 pharmacists contacted by mail, 911 (18.2%) completed the survey, of whom 836 responded to the items assessing opinions about PDMPs and provided practice site information. A majority of pharmacists across all practice settings agreed or strongly agreed with the statements that a PDMP "should be implemented in Florida" (chain 84.0%, hospital 74.2%, independent 77.9%, and other 71.1%) and that a PDMP would decrease "the incidence of doctor shopping" if implemented (chain 80.8%, hospital 67.2%, independent 71.7%, and other 63.3%). A majority of pharmacists across all practice settings disagreed or strongly disagreed with the statements that they would be "discouraged to dispense controlled substances" by the PDMP (chain 61.4%, hospital 50.0%, independent 60.2%, and other 63.8%) and that PDMP implementation would be "an invasion of patients' privacy" (chain 80.3%, hospital 67.7%, independent 67.3%, and other 69.3%). In a small-sample survey, a majority of Florida pharmacists across all practice settings were in favor of implementing a PDMP in Florida. This is the first study to examine Florida pharmacists' attitudes toward PDMP implementation, and the results should prompt future analyses of relevant outcomes, such as drug abuse, drug-related mortality, and doctor shopping.
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…
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.
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.
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.
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.
Pelleboer-Gunnink, H A; Van Oorsouw, W M W J; Van Weeghel, J; Embregts, P J C M
2017-05-01
Equal access to mainstream healthcare services for people with intellectual disabilities (ID) still requires attention. Although recent studies suggest that health professionals hold positive attitudes towards people with ID, stigmatising attitudes may influence their efforts to serve people with ID in community healthcare practice. To stimulate inclusion in mainstream healthcare services, this systematic review focussed on barriers in attitudes of mainstream health professionals towards people with ID. Five electronic databases were systematically searched and references in full text articles were checked for studies published in the English language between January 1994 and January 2016. A social-psychological triad of cognitive, affective and behavioural dimensions of stigmatising attitudes is used to structure and discuss the results. The literature search generated 2190 records with 30 studies that passed our exclusion criteria. Studies were mostly cross-sectional and of moderate quality. With respect to stigma, a lack of familiarity with and knowledge about people with ID was found. ID was considered as a stable condition not under personal control. Moreover, mainstream health professionals had either low or high expectations of the capabilities of people with ID. Professionals reported stress, lack of confidence, fear and anxiety, a tendency to treat people with ID differently and a lack of supporting autonomy. Stigmatising attitudes towards people with ID appeared to be present among mainstream health professionals. This might affect the ongoing challenges regarding inclusion in mainstream healthcare services. To facilitate inclusion in mainstream healthcare services, it is recommended to include contact and collaboration with experts-by-experience in education programs of health professionals. Future research should progress beyond descriptive accounts of stigma towards exploring relationships between cognitive, affective and behavioural dimensions as pointers for intervention. Finally, inclusion would benefit from an understanding of 'equal' treatment that means reasonable adjustments instead of undifferentiated treatment. © 2017 The Authors. Journal of Intellectual Disability Research published by MENCAP and International Association of theScientific Study of Intellectual and Developmental Disibilities and John Wiley & Sons Ltd.
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.
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.
Muftić, Lisa R; Payne, Brian K; Maljević, Almir
2015-06-01
The use of community corrections continues to grow across the globe as alternatives to incarceration are sought. Little research attention, however, has been directed at correctional alternatives from a global orientation. The purpose of this research study is to compare the way that a sample of criminal justice students from the United States (n = 118) and Bosnia and Herzegovina (n = 133) perceive electronic monitoring. Because electronic monitoring is a newer sentencing alternative and it is used differently in Bosnia and Herzegovina than it is in the United States, it is predicted that Bosnian students will view electronic monitoring differently than will students from the United States. This study finds that while students are largely supportive of electronic monitoring sentences, support is affected by offender type and student nationality. For example, Bosnian students are more supportive of electronic monitoring sentences for drug offenders while American students are more supportive of electronic monitoring sentences for juvenile offenders. Differences were also found across student groups when attitudes toward electronic monitoring and the costs and pains associated with electronic monitoring were assessed. Specifically, American students were less likely to view electronic monitoring as meeting the goals of rehabilitation and more likely to view the conditions and restrictions associated with electronic monitoring as being punitive than Bosnian students were. Implications from these findings, as well as limitations and suggestions for further research are discussed. © The Author(s) 2013.
Reis, Shmuel; Sagi, Doron; Eisenberg, Orit; Kuchnir, Yosi; Azuri, Joseph; Shalev, Varda; Ziv, Amitai
2013-12-01
Even though Electronic Medical Records (EMRs) are increasingly used in healthcare organizations there is surprisingly little theoretical work or educational programs in this field. This study is aimed at comparing two training programs for doctor-patient-computer communication (DPCC). 36 Family Medicine Residents (FMRs) participated in this study. All FMRs went through twelve identical simulated encounters, six pre and six post training. The experiment group received simulation based training (SBT) while the control group received traditional lecture based training. Performance, attitude and sense of competence of all FMRs improved, but no difference was found between the experiment and control groups. FMRs from the experiment group evaluated the contribution of the training phase higher than control group, and showed higher satisfaction. We assume that the mere exposure to simulation served as a learning experience and enabled deliberate practice that was more powerful than training. Because DPCC is a new field, all participants in such studies, including instructors and raters, should receive basic training of DPCC skills. Simulation enhances DPCC skills. Future studies of this kind should control the exposure to simulation prior to the training phase. Training and assessment of clinical communication should include EMR related skills. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
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.
DOT National Transportation Integrated Search
2014-11-01
Truck drivers and carrier personnel were interviewed on the use of electronic logging devices (ELDs) for keeping track of driving hours and whether these devices were used to harass drivers. This research examined the following issues: : Whether ...
Duke, Jennifer C; Allen, Jane A; Eggers, Matthew E; Nonnemaker, James; Farrelly, Matthew C
2016-05-01
Studies suggest that exposure to televised electronic cigarette (e-cigarette) advertising contributes to the recent increase in e-cigarette use among youth. This study examines the relationship between perceptions of e-cigarette advertisements and attitudes toward and intentions to use e-cigarettes among youth who had never used e-cigarettes. In May 2014, we conducted an online survey of 5020 youth aged 13 to 17. Participants were randomly assigned to answer questions about their attitudes toward and intentions to use e-cigarettes before or after viewing e-cigarette advertisements. Perceived effectiveness (PE) of advertisements was measured after ad exposure. Ordinary least squares models were used to assess the relationship between PE and study outcomes. Among never e-cigarette users, greater PE was associated with more positive attitudes toward e-cigarettes (b = 0.74, P < .001) and intentions to use e-cigarettes (b = 0.16, P < .001). Findings suggest that PE is predictive of outcomes controlling for study condition, youth demographics, and media use variables. After ad exposure, youth who have never used e-cigarettes previously perceive e-cigarettes as cooler, more fun, healthier, and more enjoyable. Youth who thought the ads were more effective were more likely to have a positive attitude toward e-cigarettes and greater intention to try e-cigarettes in the future. Restricting televised e-cigarette advertising may reduce e-cigarette initiation among youth. Previous studies demonstrate that, among adults, PE is antecedent to actual ad effectiveness across a range of behaviors. To our knowledge, this is the first study to document the relationship between PE and advertising effectiveness among youth. It provides evidence that PE may be a useful tool to quantify the potential influence of advertising on youth-advertising that, in this case, is designed to market a consumer good that may be harmful to youth but that may also be used to develop public health campaigns. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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.
Attitude estimation of earth orbiting satellites by decomposed linear recursive filters
NASA Technical Reports Server (NTRS)
Kou, S. R.
1975-01-01
Attitude estimation of earth orbiting satellites (including Large Space Telescope) subjected to environmental disturbances and noises was investigated. Modern control and estimation theory is used as a tool to design an efficient estimator for attitude estimation. Decomposed linear recursive filters for both continuous-time systems and discrete-time systems are derived. By using this accurate estimation of the attitude of spacecrafts, state variable feedback controller may be designed to achieve (or satisfy) high requirements of system performance.
Attributions and Attitudes of Mothers and Fathers in Kenya.
Oburu, Paul Odhiambo
2011-07-01
OBJECTIVE: The present study examined differences and similarities between Kenyan mothers and fathers in attributions regarding successes and failures in caregiving situations and progressive versus authoritarian attitudes. DESIGN: Interviews were conducted with both mothers and fathers in 100 two-parent families in Kenya. RESULTS: Mothers were more likely to make attributions regarding adult-controlled failure in caregiving situations than were fathers, but mothers and fathers did not differ on attributions regarding uncontrollable success, child-controlled failure, or authoritarian or progressive attitudes. Moderate to large correlations were found between mothers and fathers in terms of attributions regarding uncontrollable success, authoritarian attitudes, and modernity of attitudes. CONCLUSIONS: Kenyan mothers and fathers hold very similar attributions for success and failures in caregiving situations as well as parenting attitudes.
Discipline in Public and Religious Elementary and Secondary Schools: A Comparative Analysis.
ERIC Educational Resources Information Center
Denig, Stephen J.
Previous studies using the Pupil-Control Ideology Scale (PCI) have found that in general, secondary school teachers have a more custodial attitude toward pupil control than do primary school teachers, and that public school teachers have a more custodial attitude than do religious school teachers. Teachers with custodial attitudes tend to distrust…
ERIC Educational Resources Information Center
Redondo, Ignacio; Puelles, María
2017-01-01
What is going on with environmental education, which is currently unable to promote pro-environmental behaviors as effectively as it promotes pro-environmental attitudes? A tentative answer is that the environmental attitude-behavior gap observed in some individuals is just one manifestation of their lack of self-control for maintaining…
NASA Technical Reports Server (NTRS)
Amason, David L.
2008-01-01
The goal of the Solar Dynamics Observatory (SDO) is to understand and, ideally, predict the solar variations that influence life and society. It's instruments will measure the properties of the Sun and will take hifh definition images of the Sun every few seconds, all day every day. The FlatSat is a high fidelity electrical and functional representation of the SDO spacecraft bus. It is a high fidelity test bed for Integration & Test (I & T), flight software, and flight operations. For I & T purposes FlatSat will be a driver to development and dry run electrical integration procedures, STOL test procedures, page displays, and the command and telemetry database. FlatSat will also serve as a platform for flight software acceptance and systems testing for the flight software system component including the spacecraft main processors, power supply electronics, attitude control electronic, gimbal control electrons and the S-band communications card. FlatSat will also benefit the flight operations team through post-launch flight software code and table update development and verification and verification of new and updated flight operations products. This document highlights the benefits of FlatSat; describes the building of FlatSat; provides FlatSat facility requirements, access roles and responsibilities; and, and discusses FlatSat mechanical and electrical integration and functional testing.
Mendoza De La Garza, Maria; Tieu, Christina; Schroeder, Darrell; Lowe, Kathleen; Tung, Ericka
2018-06-18
Medical schools throughout the country struggle with how best to train students to provide quality, patient-centered care to the burgeoning population of older adults. The Senior Sages Program (SSP) is a longitudinal Senior Mentor Program (SMP) that offers students the opportunity to learn about the aging process and core geriatric medicine concepts through the eyes of an aging expert: their Senior Sage. The SSP marries a robust electronic curriculum with an SMP and online discussion board. The aim of this program evaluation was to measure the impact on students' geriatric knowledge and attitudes toward older adults. This asynchronously facilitated course improved students' geriatric knowledge and facilitated stability of positive attitudes toward older adults. The majority of students felt that their SSP interactions were meaningful and valuable to their clinical development. The combination of SMP and electronic curricula offer a feasible, practical way to bridge the geriatric training chasm.
Physicians' use of and attitudes toward electronic mail for patient communication.
Gaster, Barak; Knight, Christopher L; DeWitt, Dawn E; Sheffield, John V L; Assefi, Nassim P; Buchwald, Dedra
2003-05-01
To assess physicians' use of and attitudes toward electronic mail (e-mail) for patient communication, we conducted a mail-in survey of physicians who see patients in outpatient clinics affiliated with a large academic medical center (N = 283). Seventy-two percent of physicians reported using e-mail to communicate with patients, averaging 7.7 e-mails from patients per month. The lowest level of use was by community-based primary care physicians (odds ratio, 0.22; 95% confidence interval, 0.08 to 0.59). Those physicians who reported using e-mail with patients reported high satisfaction with its use. Although physicians were concerned about the confidentiality of e-mail, few discussed this issue with patients.
A pilot training manual for the terminal configured vehicle electronic attitude director indicator
NASA Technical Reports Server (NTRS)
Gandelman, J.
1980-01-01
A hard copy version is presented of a 28-minute, 90 slide audiovisual program which provides the basic instructional format for introduction to the terminal configured vehicle electronic attitude director indicator (EADI) and the strategy for learning the symbols used on the EADI and their interpretation. The basic strategy is to start with known symbols and then introduce all new symbols with emphasis appropriate to their complexity and frequency of use. The upper half of each page of the manual contains a reproduction of the slide. The text associated with the slide is found on the lower half of each page and is recorded on audio tape.
Parikh, Divya Sinha; Totañes, Francis I G; Tuliao, Alex H; Ciro, Raezelle N T; Macatangay, Bernard J C; Belizario, Vicente Y
2013-09-01
We determined the attitudes toward and practices regarding soil-transmitted helminthes (STH) control among parents and school teachers to identify reasons behind attitudes and practices that do not promote STH control. Written knowledge, attitudes and practices surveys were distributed to parents (N = 531) and teachers (N = 105) of students at 11 elementary schools in Guimaras Province, the Philippines. The survey addressed attitudes about mass drug administration (MDA), knowledge about STH control, hygienic practices, and acceptability of distributing deworming tablets among teachers. More than 90% of parents and teachers held favorable attitudes towards MDA. Sixty-nine percent of parents and 75.5% of teachers believed stool exams were necessary before MDA. Thirty-seven percent of parents stated they would not allow teachers to administer deworming tablets and 91.5% of parents feared teachers would not detect side effects of the medication. Forty-eight percent of teachers felt they could safely give deworming tablets and 81.4% of teachers were afraid of managing the side effects of deworming tablets. Forty-seven point eight percent of parents and 42.2% of teachers stated defecation in the open occured in their community. Although attitudes toward STH control were largely favorable, misconceptions about the MDA strategy, lack of support for teachers giving deworming tablets, and the practice of open defecation still exist as barriers to STH control efforts. The next step to achieve effective STH control will be to clarify misconceptions in education campaigns, to train teachers about medication administration, campaign to improve sanitation and hygiene and begin targeted mass treatment in Guimaras, the Philippines.
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.
NASA Astrophysics Data System (ADS)
van Aalderen-Smeets, Sandra I.; Walma van der Molen, Juliette H.; van Hest, Erna G. W. C. M.; Poortman, Cindy
2017-01-01
This study used an experimental, pretest-posttest control group design to investigate whether participation in a large-scale inquiry project would improve primary teachers' attitudes towards teaching science and towards conducting inquiry. The inquiry project positively affected several elements of teachers' attitudes. Teachers felt less anxious about teaching science and felt less dependent on contextual factors compared to the control group. With regard to attitude towards conducting inquiry, teachers felt less anxious and more able to conduct an inquiry project. There were no effects on other attitude components, such as self-efficacy beliefs or relevance beliefs, or on self-reported science teaching behaviour. These results indicate that practitioner research may have a partially positive effect on teachers' attitudes, but that it may not be sufficient to fully change primary teachers' attitudes and their actual science teaching behaviour. In comparison, a previous study showed that attitude-focused professional development in science education has a more profound impact on primary teachers' attitudes and science teaching behaviour. In our view, future interventions aiming to stimulate science teaching should combine both approaches, an explicit focus on attitude change together with familiarisation with inquiry, in order to improve primary teachers' attitudes and classroom practices.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Showers, D.E.
1986-01-01
This investigation assessed the relationship between knowledge about and attitudes toward nuclear energy. The study's purpose was accomplished by attempting to manipulate knowledge about and attitude toward nuclear energy independently. Over two thousand high school students participated in the study. A Non-Equivalent Control Group quasi-experimental design was used involving random assignment by intact groups to treatments. A knowledge treatment was designed to increase student knowledge without affecting attitudes. An attitude treatment was designed to change attitudes without changing knowledge, and a control treatment was employed for comparison to the experimental treatments. Each treatment consisted of a videotape with a viewingmore » guide and a homework assignment. The Nuclear Energy Assessment Battery was used as a pretest, post-test, and retention test. Males scored significantly higher in knowledge and positive attitudes, but no interaction between gender and treatment was found. The study concluded that (1) there is a correlation between nuclear knowledge and attitudes, (2) knowledge about nuclear energy can be changed without affecting attitude and attitude can be changed without affecting knowledge, and (3) students show differences and attitude based on gender.« less
NASA Astrophysics Data System (ADS)
Ousaloo, H. S.; Nodeh, M. T.; Mehrabian, R.
2016-09-01
This paper accomplishes one goal and it was to verify and to validate a Spin Magnetic Attitude Control System (SMACS) program and to perform Hardware-In-the-Loop (HIL) air-bearing experiments. A study of a closed-loop magnetic spin controller is presented using only magnetic rods as actuators. The magnetic spin rate control approach is able to perform spin rate control and it is verified with an Attitude Control System (ACS) air-bearing MATLAB® SIMULINK® model and a hardware-embedded LABVIEW® algorithm that controls the spin rate of the test platform on a spherical air bearing table. The SIMULINK® model includes dynamic model of air-bearing, its disturbances, actuator emulation and the time delays caused by on-board calculations. The air-bearing simulator is employed to develop, improve, and carry out objective tests of magnetic torque rods and spin rate control algorithm in the experimental framework and to provide a more realistic demonstration of expected performance of attitude control as compared with software-based architectures. Six sets of two torque rods are used as actuators for the SMACS. It is implemented and simulated to fulfill mission requirement including spin the satellite up to 12 degs-1 around the z-axis. These techniques are documented for the full nonlinear equations of motion of the system and the performances of these techniques are compared in several simulations.
Integrated identification and control for nanosatellites reclaiming failed satellite
NASA Astrophysics Data System (ADS)
Han, Nan; Luo, Jianjun; Ma, Weihua; Yuan, Jianping
2018-05-01
Using nanosatellites to reclaim a failed satellite needs nanosatellites to attach to its surface to take over its attitude control function. This is challenging, since parameters including the inertia matrix of the combined spacecraft and the relative attitude information of attached nanosatellites with respect to the given body-fixed frame of the failed satellite are all unknown after the attachment. Besides, if the total control capacity needs to be increased during the reclaiming process by new nanosatellites, real-time parameters updating will be necessary. For these reasons, an integrated identification and control method is proposed in this paper, which enables the real-time parameters identification and attitude takeover control to be conducted concurrently. Identification of the inertia matrix of the combined spacecraft and the relative attitude information of attached nanosatellites are both considered. To guarantee sufficient excitation for the identification of the inertia matrix, a modified identification equation is established by filtering out sample points leading to ill-conditioned identification, and the identification performance of the inertia matrix is improved. Based on the real-time estimated inertia matrix, an attitude takeover controller is designed, the stability of the controller is analysed using Lyapunov method. The commanded control torques are allocated to each nanosatellite while the control saturation constraint being satisfied using the Quadratic Programming (QP) method. Numerical simulations are carried out to demonstrate the feasibility and effectiveness of the proposed integrated identification and control method.
NASA Astrophysics Data System (ADS)
Johari, A. H.; Muslim
2018-05-01
Experiential learning model using simple physics kit has been implemented to get a picture of improving attitude toward physics senior high school students on Fluid. This study aims to obtain a description of the increase attitudes toward physics senior high school students. The research method used was quasi experiment with non-equivalent pretest -posttest control group design. Two class of tenth grade were involved in this research 28, 26 students respectively experiment class and control class. Increased Attitude toward physics of senior high school students is calculated using an attitude scale consisting of 18 questions. Based on the experimental class test average of 86.5% with the criteria of almost all students there is an increase and in the control class of 53.75% with the criteria of half students. This result shows that the influence of experiential learning model using simple physics kit can improve attitude toward physics compared to experiential learning without using simple physics kit.
de Boer, Anke; Pijl, Sip Jan; Minnaert, Alexander; Post, Wendy
2014-03-01
In this study we examine the effectiveness of an intervention program to influence attitudes of elementary school students towards peers with intellectual, physical and severe physical and intellectual disabilities. A quasi-experimental longitudinal study was designed with an experimental group and a control group, both comprising two rural schools. An intervention program was developed for kindergarten (n(experimental) = 22, n(control) = 31) and elementary school students without disabilities (n(experimental) = 91, n(control) = 127) (age range 4-12 years old). This intervention consisted of a 3 weeks education project comprising six lessons about disabilities. The Acceptance Scale for Kindergarten-revised and the Attitude Survey to Inclusive Education were used to measure attitudes at three moments: prior to the start of the intervention, after the intervention and 1 year later. The outcomes of the multilevel analysis showed positive, immediate effects on attitudes of kindergarten students, but limited effects on elementary school students' attitudes.
Chiu, Yen-Lin; Tsai, Chin-Chung; Fan Chiang, Chih-Yun
2013-04-01
The purpose of this study was to explore the relationships between job characteristics (job demands, job control and social support) and nurses' attitudes toward web-based continuing learning. A total of 221 in-service nurses from hospitals in Taiwan were surveyed. The Attitudes toward Web-based Continuing Learning Survey (AWCL) was employed as the outcome variables, and the Chinese version Job Characteristic Questionnaire (C-JCQ) was administered to assess the predictors for explaining the nurses' attitudes toward web-based continuing learning. To examine the relationships among these variables, hierarchical regression was conducted. The results of the regression analysis revealed that job control and social support positively associated with nurses' attitudes toward web-based continuing learning. However, the relationship of job demands to such learning was not significant. Moreover, a significant demands×job control interaction was found, but the job demands×social support interaction had no significant relationships with attitudes toward web-based continuing learning. Copyright © 2013 Elsevier Ltd. All rights reserved.
How to make the fourth revolution: Human factors in the adoption of electronic instructional aids
NASA Technical Reports Server (NTRS)
Demerath, N. J.; Daniels, L. A.
1973-01-01
The prospects and problems of getting higher education in the United States (high school and above) to more fully utilize electronic technologies are examined. Sociological, psychological, and political factors are analyzed to determine the feasibility of adopting electronic instructional techniques. Differences in organizations, attitudes, and customs of different kinds of students, teachers, administrators, and publics are crucial factors in innovation.
The Theory of Planned Behavior and E-cig Use: Impulsive Personality, E-cig Attitudes, and E-cig Use.
Hershberger, Alexandra; Connors, Miranda; Um, Miji; Cyders, Melissa A
2018-04-01
The current paper applied the Theory of Planned Behavior (TPB; Ajzen & Fishbein, 1988) to understand how impulsive personality traits and attitudes concerning e-cig use relate to the likelihood of electronic cigarette (e-cig) use. Seven hundred and fourteen participants (Mean age = 34.04, SD = 10.89, 48.6% female) completed cross-sectional measures of e-cig use attitudes (CEAC) and the Short UPPS-P Impulsive Behavior Scale. A structural path analysis suggested that urgency and deficits in conscientiousness were significantly related to e-cig attitudes (CFI = 0.99, TLI = 0.99, RMSEA = 0.02; urgency: β = 0.32, p = .001; deficits in conscientiousness: β = -0.48, p < .001). E-cig attitude scores were significantly higher for e-cig users than non-users, β = 0.85, p < .001. There was no significant direct path from impulsive personality traits to e-cig use. Findings provide initial support for a model in which impulsive traits are related to e-cig use through positive e-cig attitudes.
Predictors of Attitudes toward Childlessness.
ERIC Educational Resources Information Center
Spreadbury, Connie
The study assessed young adults' attitudes toward childlessness and identified certain factors which predict positive or negative attitudes toward childlessness. The author anticipated finding changes in attitudes because of recent social developments such as awareness of world overpopulation, availability of birth control methods, pressure for…
Are You Ready to Go Digital?: The Pros and Cons of Electronic Portfolio Development
ERIC Educational Resources Information Center
Heath, Marilyn
2005-01-01
There is an increasing need for educators to have professional portfolios, which are considered to be authentic tools for evaluating the knowledge, skill, beliefs and attitudes of prospective educators. Electronic portfolios are gaining in popularity and their relative pros and cons are examined.
Investigating Students' Usage and Acceptance of Electronic Books
ERIC Educational Resources Information Center
Sieche, Susan; Krey, Birte; Bastiaens, Theo
2013-01-01
The purpose of this study is to investigate students' usage and acceptance of electronic books. Factors correlating with students' attitude towards e-books were examined using the Technology Acceptance Model (Davis, Bagozzi, & Warshaw 1989). A questionnaire was administered online for students at University of Hagen. Results indicate that…
Smits, P B A; de Graaf, L; Radon, K; de Boer, A G; Bos, N R; van Dijk, F J H; Verbeek, J H A M
2012-04-01
Undergraduate medical teaching in occupational health (OH) is a challenge in universities around the world. Case-based e-learning with an attractive clinical context could improve the attitude of medical students towards OH. The study question is whether case-based e-learning for medical students is more effective in improving knowledge, satisfaction and a positive attitude towards OH than non-case-based textbook learning. Participants, 141 second year medical students, were randomised to either case-based e-learning or text-based learning. Outcome measures were knowledge, satisfaction and attitude towards OH, measured at baseline, directly after the intervention, after 1 week and at 3-month follow-up. Of the 141 participants, 130 (92%) completed the questionnaires at short-term follow-up and 41 (29%) at 3-month follow-up. At short-term follow-up, intervention and control groups did not show a significant difference in knowledge nor satisfaction but attitude towards OH was significantly more negative in the intervention group (F=4.041, p=0.047). At 3-month follow-up, there were no significant differences between intervention and control groups for knowledge, satisfaction and attitude. We found a significant decrease in favourable attitude during the internship in the experimental group compared with the control group. There were no significant differences in knowledge or satisfaction between case-based e-learning and text-based learning. The attitude towards OH should be further investigated as an outcome of educational programmes.
NASA Technical Reports Server (NTRS)
Franklin, J. A.; Innis, R. C.
1972-01-01
Analytical investigations and piloted moving base simulator evaluations were conducted for manual control of pitch attitude, flight path, and airspeed for the approach and landing of a powered lift jet STOL aircraft. Flight path and speed response characteristics were described analytically and were evaluated for the simulation experiments which were carried out on a large motion simulator. The response characteristics were selected and evaluated for a specified path and speed control technique. These charcteristics were: (1) the initial pitch response and steady pitch rate sensitivity for control of attitude with a pitch rate command/ attitude hold system, (2) the initial flight path response, flight path overshoot, and flight path-airspeed coupling in response to a change in thrust, and (3) the sensitivity of airspeed to pitch attitude changes. Results are presented in the form of pilot opinion ratings and commentary, substantiated where appropriate by response time histories and aircraft states at the point of touchdown.
An overview of integrated flywheel technology for aerospace application
NASA Technical Reports Server (NTRS)
Keckler, C. R.; Groom, N. J.
1985-01-01
Space missions ranging from small scientific satellites to large manned spacecraft have, for many years, utilized systems of spinning flywheels to maintain vehicle attitude. These systems have included momentum and reaction wheels as well as control moment gyros. Extension of that technology to satisfy the additional tasks associated with energy storage has also been pursued. The combining of control and energy storage features into one system has been examined by NASA for space applications and demonstrated in the laboratory. The impact of technology advances in such areas as composite material rotors, magnetic suspensions, motor/generators, and electronics have prompted a re-evaluation of the viability of the flywheel storage system concept for aerospace applications. This paper summarizes the results of this re-examination and identifies shortfalls in the various technology areas.
NASA Technical Reports Server (NTRS)
1979-01-01
Failures and deficiencies in flight programs are reviewed and suggestions are made for avoiding them. The technology development problem areas considered are control configured vehicle design, gyros, solid state star sensors, control instrumentation, tolerant/accomodating control systems, large momentum exchange devices, and autonomous rendezvous and docking.
Design study for LANDSAT D attitude control system
NASA Technical Reports Server (NTRS)
Iwens, R. P.; Bernier, G. E.; Hofstadter, R. F.
1976-01-01
A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed.
1970-01-01
This photograph shows technicians installing the meteoroid shield on the Thruster Attitude Control Subsystem (TACS). At one end of the Orbital Workshop (OWS), the TACS provided short-term control of the attitude of the Skylab.
Spacecraft attitude control for a solar electric geosynchronous transfer mission
NASA Technical Reports Server (NTRS)
Leroy, B. E.; Regetz, J. D., Jr.
1975-01-01
A study of the Attitude Control System (ACS) is made for a solar electric propulsion geosynchronous transfer mission. The basic mission considered is spacecraft injection into a low altitude, inclined orbit followed by low thrust orbit changing to achieve geosynchronous orbit. Because of the extended thrusting time, the mission performance is a strong function of the attitude control system. Two attitude control system design options for an example mission evolve from consideration of the spacecraft configuration, the environmental disturbances, and the probable ACS modes of operation. The impact of these design options on other spacecraft subsystems is discussed. The factors which must be considered in determining the ACS actuation and sensing subsystems are discussed. The effects of the actuation and sensing subsystems on the mission performance are also considered.
Precision tethered satellite attitude control. Ph.D. Thesis
NASA Technical Reports Server (NTRS)
Kline-Schoder, Robert J.
1990-01-01
Tethered spacecraft possess unique dynamic characteristics which make them advantageous for certain classes of experiments. One use for which tethers are particularly well suited is to provide an isolated platform for spaceborne observatories. The advantages of tethering a pointing platform 1 or 2 km from a space shuttle or space station are that, compared to placing the observatory on the parent spacecraft, vibrational disturbances are attenuated and contamination is eliminated. In practice, all satellites have some requirement on the attitude control of the spacecraft, and tethered satellites are no exception. It has previously been shown that conventional means of performing attitude control for tethered satellites are insufficient for any mission with pointing requirements more stringent than about 1 deg. This is due mainly to the relatively large force applied by the tether to the spacecraft. A particularly effective method of implementing attitude control for tethered satellites is to use this tether tension force to generate control torques by moving the tether attach point relative to the subsatellite center of mass. A demonstration of this attitude control technique on an astrophysical pointing platform has been proposed for a space shuttle flight test project and is referred to as the Kinetic Isolation Tether Experiment (KITE).
Stricklin, Mary Lou; Bierer, S Beth; Struk, Cynthia
2003-01-01
Point-of-care technology for home care use will be the final step in enterprise-wide healthcare electronic communications. Successful implementation of home care point-of-care technology hinges upon nurses' attitudes toward point-of-care technology and its use in clinical practice. This study addresses the factors associated with home care nurses' attitudes using Stronge and Brodt's Nurse Attitudes Toward Computers instrument. In this study, the Nurses Attitudes Toward Computers instrument was administered to a convenience sample of 138 nurses employed by a large midwestern home care agency, with an 88% response rate. Confirmatory factor analysis corroborated the Nurses Attitudes Toward Computers' 3-dimensional factor structure for practicing nurses, which was labeled as nurses' work, security issues, and perceived barriers. Results from the confirmatory factor analysis also suggest that these 3 factors are internally correlated and represent multiple dimensions of a higher order construct labeled as nurses' attitudes toward computers. Additionally, two of these factors, nurses' work and perceived barriers, each appears to explain more variance in nurses' attitudes toward computers than security issues. Instrument reliability was high for the sample (.90), with subscale reliabilities ranging from 86 to 70.
Yudin, Mark H; Money, Deborah M; Cheung, Matthew C; Loutfy, Mona R
2012-01-01
Family and pregnancy planning are important for HIV-infected individuals and couples. There is a paucity of data regarding physician attitudes with respect to reproduction in this population, but some evidence suggests that attitudes can influence the information, advice, and services they will provide. To determine physician attitudes toward pregnancy, fertility care, and access to assisted reproductive technologies for HIV-infected individuals, and to determine whether attitudes differed based on specific physician characteristics. A survey was sent electronically to obstetrician/gynecologists and infectious disease specialists in Canada. Items were grouped into 5 key domains: physician demographics, physician attitudes toward pregnancy and adoption, physician attitudes toward fertility care, physician attitudes toward assisted reproductive technology, and challenges for an HIV-infected population. Attitudes were determined based on answers to individual questions and also for each domain. Univariate and logistic regression analyses were used to determine the influence of specific physician characteristics on attitudes. Completed surveys were received from 165 physicians. Most had positive attitudes regarding pregnancy or adoption (89%), fertility care (72%), and assisted reproductive technology (79%). In multivariate analyses, having cared for HIV-infected patients was significantly associated with having a positive attitude toward fertility care or assisted reproductive technology. In this national survey of Canadian physicians, most had positive attitudes toward pregnancy, adoption, fertility care, and use of assisted reproductive technology among HIV-infected persons. Physicians who had cared for HIV-infected individuals in the past were more likely to have positive attitudes than those who had not.
Attributions and Attitudes of Mothers and Fathers in Colombia.
Di Giunta, Laura; Tirado, Liliana M Uribe; Márquez, Luz A Araque
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 108 Colombian families. RESULTS: Fathers reported higher uncontrollable success attributions and higher authoritarian attitudes than did mothers, whereas mothers reported higher modernity of attitudes than did fathers; only the gender differences related to parental attitudes 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 and progressive attitudes after controlling for parents' age, education, and possible social desirability bias. CONCLUSIONS: This work elucidates ways that parent gender relates to attributions regarding parents' success and failure in caregiving and to progressive versus authoritarian parenting attitudes in Colombia.
Attributions and Attitudes of Mothers and Fathers in Colombia
Di Giunta, Laura; Tirado, Liliana M. Uribe; Márquez, Luz A. Araque
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 108 Colombian families. Results Fathers reported higher uncontrollable success attributions and higher authoritarian attitudes than did mothers, whereas mothers reported higher modernity of attitudes than did fathers; only the gender differences related to parental attitudes 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 and progressive attitudes after controlling for parents’ age, education, and possible social desirability bias. Conclusions This work elucidates ways that parent gender relates to attributions regarding parents’ success and failure in caregiving and to progressive versus authoritarian parenting attitudes in Colombia. PMID:21927585
Hardware Simulations of Spacecraft Attitude Synchronization Using Lyapunov-Based Controllers
NASA Astrophysics Data System (ADS)
Jung, Juno; Park, Sang-Young; Eun, Youngho; Kim, Sung-Woo; Park, Chandeok
2018-04-01
In the near future, space missions with multiple spacecraft are expected to replace traditional missions with a single large spacecraft. These spacecraft formation flying missions generally require precise knowledge of relative position and attitude between neighboring agents. In this study, among the several challenging issues, we focus on the technique to control spacecraft attitude synchronization in formation. We develop a number of nonlinear control schemes based on the Lyapunov stability theorem and considering special situations: full-state feedback control, full-state feedback control with unknown inertia parameters, and output feedback control without angular velocity measurements. All the proposed controllers offer absolute and relative control using reaction wheel assembly for both regulator and tracking problems. In addition to the numerical simulations, an air-bearing-based hardware-in-the-loop (HIL) system is used to verify the proposed control laws in real-time hardware environments. The pointing errors converge to 0.5{°} with numerical simulations and to 2{°} using the HIL system. Consequently, both numerical and hardware simulations confirm the performance of the spacecraft attitude synchronization algorithms developed in this study.
ERIC Educational Resources Information Center
Stuessy, Carol L.; Rowland, Paul McD.
Locus of control, a generalized belief about causality in one's personal life, was identified as a potential variable impinging upon the acquisition of science-related attitudes in classes of high school students from 10th grade biology, and 11th and 12th grade chemistry, and of college elementary education majors. Correlations of the…
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)
Smith, G. A.; Meyer, G.
1981-01-01
A full envelope automatic flight control system based on nonlinear inverse systems concepts has been applied to a vertical attitude takeoff and landing (VATOL) fighter aircraft. A new method for using an airborne digital aircraft model to perform the inversion of a nonlinear aircraft model is presented together with the results of a simulation study of the nonlinear inverse system concept for the vertical-attitude hover mode. The system response to maneuver commands in the vertical attitude was found to be excellent; and recovery from large initial offsets and large disturbances was found to be very satisfactory.
Matosic, Doris; Ntoumanis, Nikos; Boardley, Ian David; Stenling, Andreas; Sedikides, Constantine
2016-12-01
Research on coaching (Bartholomew, Ntoumanis, & Thøgersen-Ntoumani, 2009) has shown that coaches can display controlling behaviors that have detrimental effects on athletes' basic psychological needs and quality of sport experiences. The current study extends this literature by considering coach narcissism as a potential antecedent of coaches' controlling behaviors. Further, the study tests a model linking coaches' (n = 59) own reports of narcissistic tendencies with athletes' (n = 493) perceptions of coach controlling behaviors, experiences of need frustration, and attitudes toward doping. Multilevel path analysis revealed that coach narcissism was directly and positively associated with athletes' perceptions of controlling behaviors and was indirectly and positively associated with athletes' reports of needs frustration. In addition, athletes' perceptions of coach behaviors were positively associated-directly and indirectly-with attitudes toward doping. The findings advance understanding of controlling coach behaviors, their potential antecedents, and their associations with athletes' attitudes toward doping.
Addressing Younger Workers' Needs: The Promoting U through Safety and Health (PUSH) Trial Outcomes.
Rohlman, Diane S; Parish, Megan; Elliot, Diane L; Hanson, Ginger; Perrin, Nancy
2016-08-10
Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health). All younger workers (14-24 years old) hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years) completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen's d) 0.4). However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior.
Addressing Younger Workers’ Needs: The Promoting U through Safety and Health (PUSH) Trial Outcomes
Rohlman, Diane S.; Parish, Megan; Elliot, Diane L.; Hanson, Ginger; Perrin, Nancy
2016-01-01
Most younger workers, less than 25 years old, receive no training in worker safety. We report the feasibility and outcomes of a randomized controlled trial of an electronically delivered safety and health curriculum for younger workers entitled, PUSH (Promoting U through Safety and Health). All younger workers (14–24 years old) hired for summer work at a large parks and recreation organization were invited to participate in an evaluation of an online training and randomized into an intervention or control condition. Baseline and end-of-summer online instruments assessed acceptability, knowledge, and self-reported attitudes and behaviors. One-hundred and forty participants (mean age 17.9 years) completed the study. The innovative training was feasible and acceptable to participants and the organization. Durable increases in safety and health knowledge were achieved by intervention workers (p < 0.001, effect size (Cohen’s d) 0.4). However, self-reported safety and health attitudes did not improve with this one-time training. These results indicate the potential utility of online training for younger workers and underscore the limitations of a single training interaction to change behaviors. Interventions may need to be delivered over a longer period of time and/or include environmental components to effectively alter behavior. PMID:27517968
Spherical gyroscopic moment stabilizer for attitude control of microsatellites
NASA Astrophysics Data System (ADS)
Keshtkar, Sajjad; Moreno, Jaime A.; Kojima, Hirohisa; Uchiyama, Kenji; Nohmi, Masahiro; Takaya, Keisuke
2018-02-01
This paper presents a new and improved concept of recently proposed two-degrees of freedom spherical stabilizer for triaxial orientation of microsatellites. The analytical analysis of the advantages of the proposed mechanism over the existing inertial attitude control devices are introduced. The extended equations of motion of the stabilizing satellite including the spherical gyroscope, for control law design and numerical simulations, are studied in detail. A new control algorithm based on continuous high-order sliding mode algorithms, for managing the torque produced by the stabilizer and therefore the attitude control of the satellite in the presence of perturbations/uncertainties, is presented. Some numerical simulations are carried out to prove the performance of the proposed mechanism and control laws.
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.
Autonomous Control Modes and Optimized Path Guidance for Shipboard Landing in High Sea States
2017-01-09
due to the inherent nose up attitude of the helicopter. Once the tail gear makes contact (almost always with low relative velocity), the control...n V Z ( ft /s ) Front Gear 2 -10 -8 -6 -4 -2 0 2 4 6 8 10 0 2 4 6 8 10 Touchdown V Y (ft/s) Tail Gear This problem is a consequence of attitude ...mismatch at touchdown; where the aircraft attitude does not comply with the deck orientation. Attitude mismatch is a common for helicopter; even a land
NASA Astrophysics Data System (ADS)
Eardley, Julie Anne
The purpose of this study was to determine the effect of different instructional media (computer assisted instruction (CAI) tutorial vs. traditional textbook) on student attitudes toward science and computers and achievement scores in a team-taught integrated science course, ENS 1001, "The Whole Earth Course," which was offered at Florida Institute of Technology during the Fall 2000 term. The effect of gender on student attitudes toward science and computers and achievement scores was also investigated. This study employed a randomized pretest-posttest control group experimental research design with a sample of 30 students (12 males and 18 females). Students had registered for weekly lab sessions that accompanied the course and had been randomly assigned to the treatment or control group. The treatment group used a CAI tutorial for completing homework assignments and the control group used the required textbook for completing homework assignments. The Attitude toward Science and Computers Questionnaire and Achievement Test were the two instruments administered during this study to measure students' attitudes and achievement score changes. A multivariate analysis of covariance (MANCOVA), using hierarchical multiple regression/correlation (MRC), was employed to determine: (1) treatment versus control group attitude and achievement differences; and (2) male versus female attitude and achievement differences. The differences between the treatment group's and control group's homework averages were determined by t test analyses. The overall MANCOVA model was found to be significant at p < .05. Examining research factor set independent variables separately resulted in gender being the only variable that significantly contributed in explaining the variability in a dependent variable, attitudes toward science and computers. T test analyses of the homework averages showed no significant differences. Contradictory to the findings of this study, anecdotal information from personal communication, course evaluations, and homework assignments indicated favorable attitudes and higher achievement scores for a majority of the students in the treatment group.
Jabben, Nienke; Arts, Baer; Jongen, Ellen M M; Smulders, Fren T Y; van Os, Jim; Krabbendam, Lydia
2012-12-20
Research in cognitive processes and attitudes in bipolar disorder is scarce and has provided mixed findings, possibly due to differences in current mood state. It is unclear whether alterations in cognitive processes and attitudes are only related to the depressive mood states of bipolar patients or also represent a vulnerability marker for the development of future (depressive) episodes. This was investigated in the current study. Both implicit (attentional bias for emotional words) and explicit (dysfunctional attitudes and personality characteristics) measures of cognitive processes and attitudes were assessed in 77 bipolar patients with varying levels of depressive symptoms (depressed=17, euthymic n=60), their healthy first-degree relatives (n=39) and a healthy control group (n=61). Analyses of variance were used to investigate differences between groups. Mildly depressed patients with bipolar disorder demonstrated an attentional bias away from positive emotional words and showed increased dysfunctional attitudes and higher levels of neuroticism. Euthymic patients were largely comparable to healthy controls and only differed from controls in higher levels of neuroticism. Relatives were similar to controls on all measures, although they significantly differed from bipolar patients in displaying less neuroticism and more extraversion. No firm conclusions regarding causality can be drawn from the associations that were found between cognitive processes and attitudes and the evolution of mood symptoms in bipolar disorder. Alterations in cognitive processes and attitudes in bipolar patients appear to be mostly related to the expression of mood symptomatology rather than to the vulnerability for bipolar disorder. Copyright © 2012 Elsevier B.V. All rights reserved.
75 FR 21040 - Submission for OMB Review: Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-22
...: National Survey of Public Attitudes Towards People With Disabilities. OMB Control Number: Pending. Agency... assess public attitudes towards people with disabilities with a focus on workplace relations. The survey... attitudes of individuals and develops ways of changing those attitudes to improve the employment rate and...
Solar and Heliospheric Observatory (SOHO) Flight Dynamics Simulations Using MATLAB (R)
NASA Technical Reports Server (NTRS)
Headrick, R. D.; Rowe, J. N.
1996-01-01
This paper describes a study to verify onboard attitude control laws in the coarse Sun-pointing (CSP) mode by simulation and to develop procedures for operational support for the Solar and Heliospheric Observatory (SOHO) mission. SOHO was launched on December 2, 1995, and the predictions of the simulation were verified with the flight data. This study used a commercial off the shelf product MATLAB(tm) to do the following: Develop procedures for computing the parasitic torques for orbital maneuvers; Simulate onboard attitude control of roll, pitch, and yaw during orbital maneuvers; Develop procedures for predicting firing time for both on- and off-modulated thrusters during orbital maneuvers; Investigate the use of feed forward or pre-bias torques to reduce the attitude handoff during orbit maneuvers - in particular, determine how to use the flight data to improve the feed forward torque estimates for use on future maneuvers. The study verified the stability of the attitude control during orbital maneuvers and the proposed use of feed forward torques to compensate for the attitude handoff. Comparison of the simulations with flight data showed: Parasitic torques provided a good estimate of the on- and off-modulation for attitude control; The feed forward torque compensation scheme worked well to reduce attitude handoff during the orbital maneuvers. The work has been extended to prototype calibration of thrusters from observed firing time and observed reaction wheel speed changes.
Food choice motives, attitude towards and intention to adopt personalised nutrition.
Rankin, Audrey; Bunting, Brendan P; Poínhos, Rui; van der Lans, Ivo A; Fischer, Arnout Rh; Kuznesof, Sharron; Almeida, Mdv; Markovina, Jerko; Frewer, Lynn J; Stewart-Knox, Barbara J
2018-05-17
The present study explored associations between food choice motives, attitudes towards and intention to adopt personalised nutrition, to inform communication strategies based on consumer priorities and concerns.Design/SettingA survey was administered online which included the Food Choice Questionnaire (FCQ) and items assessing attitudes towards and intention to adopt personalised nutrition. Nationally representative samples were recruited in nine EU countries (n 9381). Structural equation modelling indicated that the food choice motives 'weight control', 'mood', 'health' and 'ethical concern' had a positive association and 'price' had a negative association with attitude towards, and intention to adopt, personalised nutrition. 'Health' was positively associated and 'familiarity' negatively associated with attitude towards personalised nutrition. The effects of 'weight control', 'ethical concern', 'mood' and 'price' on intention to adopt personalised nutrition were partially mediated by attitude. The effects of 'health' and 'familiarity' were fully mediated by attitude. 'Sensory appeal' was negatively and directly associated with intention to adopt personalised nutrition. Personalised nutrition providers may benefit from taking into consideration the importance of underlying determinants of food choice in potential users, particularly weight control, mood and price, when promoting services and in tailoring communications that are motivationally relevant.
Attitude Model of a Reaction Wheel/Fixed Thruster Based Satellite Using Telemetry Data
2005-03-01
xii ATTITUDE MODEL OF A REACTION WHEEL/ FIXED THRUSTER BASED SATELLITE USING TELEMETRY DATA I. Introduction As technology advances and spacecraft ...Earth’s horizon to determine spacecraft attitude . Sun sensors use the Sun to determine spacecraft attitude and are currently the attitude determination...wheels and the rate of rotation of the gimbal. Gravity gradient stabilization is a passive attitude control technique that is designed to use the
NASA Technical Reports Server (NTRS)
Mauldin, Rebecca H.
2010-01-01
In order to study and control the attitude of a spacecraft, it is necessary to understand the natural motion of a body in orbit. Assuming a spacecraft to be a rigid body, dynamics describes the complete motion of the vehicle by the translational and rotational motion of the body. The Simulink Attitude Analysis Model applies the equations of rigid body motion to the study of a spacecraft?s attitude in orbit. Using a TCP/IP connection, Matlab reads the values of the Remote Manipulator System (RMS) hand controllers and passes them to Simulink as specified torque and impulse profiles. Simulink then uses the governing kinematic and dynamic equations of a rigid body in low earth orbit (LE0) to plot the attitude response of a spacecraft for five seconds given known applied torques and impulses, and constant principal moments of inertia.
Flight test results for a separate surface stability augmented Beech model 99
NASA Technical Reports Server (NTRS)
Jenks, G. E.; Henry, H. F.; Roskam, J.
1977-01-01
A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis.
Logsdon, M. Cynthia; Pinto, Melissa D.; LaJoie, A. Scott; Hertweck, Paige; Lynch, Tania; Flamini, Laura
2013-01-01
PROBLEM To examine predictors of intention to seek mental health treatment for adolescent girls in mothers and daughters. METHODS In this cross-sectional study, mothers and adolescent daughters (n = 71) completed measures of behavioral attitudes, subjective norms, perceived behavioral control, and intention to seek mental health treatment for the adolescent daughter. FINDINGS Behavioral attitude and perceived behavioral control predicted intention to seek mental health treatment among mothers. Behavioral attitude predicted intention among daughters. There were no associations between mothers and daughters on study variables. CONCLUSIONS To promote shared decision making and engagement in mental health treatment, clinicians may target interventions to the mother’s perceived behavioral control and behavioral attitudes of daughters and mothers. Based upon study results, clinicians should promote shared decision making and concordance between mothers and daughters on attitudes toward mental health treatment. PMID:24180603
Gaylin, Daniel S; Moiduddin, Adil; Mohamoud, Shamis; Lundeen, Katie; Kelly, Jennifer A
2011-01-01
Objective To understand Americans' attitudes concerning health information technology's (IT's) potential to improve health care and differences in those attitudes based on demographics and technological affinity. Data Sources/Study Setting A random-digit-dial sample with known probability of selection for every household in the United States with a telephone, plus a supplemental sample of cell phone users. Telephone interviews were conducted from August 2009 through November 2009. Study Design Data were analyzed to present univariate estimates of Americans' opinions of health IT, as well as multivariate logistic regressions to assess hypotheses relating individuals' characteristics to their opinions. Characteristics used in our model include age, race, ethnicity, gender, income, and affinity to technology. Findings A large majority (78 percent) favor use of electronic medical records (EMRs); believe EMRs could improve care and reduce costs (78 percent and 59 percent, respectively); believe benefits of EMR use outweigh privacy risks (64 percent); and support health care information sharing among providers (72 percent). Regression analyses show more positive attitudes among those with higher incomes and greater comfort using electronic technologies. Conclusion The findings suggest that American's believe that health IT adoption is an effective means to improve the quality and safety of health care. PMID:21275986
14 CFR 23.147 - Directional and lateral control.
Code of Federal Regulations, 2010 CFR
2010-01-01
... attitude or encountering dangerous characteristics, in the event of a sudden and complete failure of the... continued safe flight and the ability to maintain attitudes suitable for a controlled landing without...
NASA Workshop on Hybrid (Mixed-Actuator) Spacecraft Attitude Control
NASA Technical Reports Server (NTRS)
Dennehy, Cornelius J.; Kunz, Nans
2014-01-01
At the request of the Science Mission Directorate Chief Engineer, the NASA Technical Fellow for Guidance, Navigation & Control assembled and facilitated a workshop on Spacecraft Hybrid Attitude Control. This multi-Center, academic, and industry workshop, sponsored by the NASA Engineering and Safety Center (NESC), was held in April 2013 to unite nationwide experts to present and discuss the various innovative solutions, techniques, and lessons learned regarding the development and implementation of the various hybrid attitude control system solutions investigated or implemented. This report attempts to document these key lessons learned with the 16 findings and 9 NESC recommendations.
Inflight redesign of the IUE attitude control system
NASA Technical Reports Server (NTRS)
Femiano, M. D.
1986-01-01
The one- and two-gyro system designs of the International Ultraviolet Explorer (IUE) attitude control system (ACS) are examined. The inertial reference assembly that provides the primary attitude reference for IUE consists of six rate sensors which are single-axis rate integrating gyros. The gyros operate in a pulse rebalanced mode that produces an output pulse for 0.01 arcsec of motion about the input axis. The functions of the fine error sensor, fine sun sensor (FSS), the IUE reaction wheels, the onboard computer, and the hold/slew algorithm are described. The use of the hold/slew algorithm to compute the control voltage for the ACS based on the Kalman filter is studied. A two-gyro system was incorporated into IUE following gyro failure. The procedures for establishing attitude control with the two-gyro design based on the FSS is analyzed. The performance of the two-gyro system is evaluated; it is observed that the pitch and yaw gyro control is 0.24 arcsec and the control is sufficient to permit extended periods of observation.
Simultaneous calibrations of Voyager celestial and inertial attitude control systems in flight
NASA Technical Reports Server (NTRS)
Jahanshahi, M. H.
1982-01-01
A mathematical description of the data reduction technique used to simultaneously calibrate the Voyager celestial and inertial attitude control subsystems is given. It is shown that knowledge of the spacecraft limit cycle motion, as measured by the celestial and the inertial sensors, is adequate to result in the estimates of a selected number of errors which adversely affect the spacecraft attitude knowledge.
Xu, Yaoshan; Li, Yongjuan; Ding, Weidong; Lu, Fan
2014-01-01
This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end.
Xu, Yaoshan; Li, Yongjuan; Ding, Weidong; Lu, Fan
2014-01-01
This study explores the precursors of employees' safety behaviors based on a dual-process model, which suggests that human behaviors are determined by both controlled and automatic cognitive processes. Employees' responses to a self-reported survey on safety attitudes capture their controlled cognitive process, while the automatic association concerning safety measured by an Implicit Association Test (IAT) reflects employees' automatic cognitive processes about safety. In addition, this study investigates the moderating effects of inhibition on the relationship between self-reported safety attitude and safety behavior, and that between automatic associations towards safety and safety behavior. The results suggest significant main effects of self-reported safety attitude and automatic association on safety behaviors. Further, the interaction between self-reported safety attitude and inhibition and that between automatic association and inhibition each predict unique variances in safety behavior. Specifically, the safety behaviors of employees with lower level of inhibitory control are influenced more by automatic association, whereas those of employees with higher level of inhibitory control are guided more by self-reported safety attitudes. These results suggest that safety behavior is the joint outcome of both controlled and automatic cognitive processes, and the relative importance of these cognitive processes depends on employees' individual differences in inhibitory control. The implications of these findings for theoretical and practical issues are discussed at the end. PMID:24520338
Moradi Khanghahi, Behnam; Jamali, Zahra; Pournaghi Azar, Fatemeh; Naghavi Behzad, Mohammad; Azami-Aghdash, Saber
2013-01-01
Background and aims Infection control is an important issue in dentistry, and the dentists are primarily responsible for observing the relevant procedures. Therefore, the present study evaluated knowledge, attitude, practice, and status of infection control among Iranian dentists through systematic review of published results. Materials and methods In this systematic review, the required data was collected searching for keywords including infection, infection control, behavior, performance, practice, attitude, knowledge, dent*, prevention, Iran* and their Persian equivalents in PubMed, Science Direct, Iranmedex, SID, Medlib, and Magiran databases with a time limit of 1985 to 2012. Out of 698 articles, 15 completely related articles were finally considered and the rest were excluded due to lake of relev-ance to the study goals. The required data were extracted and summarized in an Extraction Table and were analyzed ma-nually. Results Evaluating the results of studies indicated inappropriate knowledge, attitude, and practice regarding infection control among Iranian dentists and dental students. Using personal protection devices and observing measures required for infection control were not in accordance with global standards. Conclusion The knowledge, attitudes, and practice of infection control in Iranian dental settings were found to be inadequate. Therefore, dentists should be educated more on the subject and special programs should be in place to monitor the dental settings for observing infection control standards. PMID:23875081
Sexual Experience and Responses to a Birth Control Film.
ERIC Educational Resources Information Center
Herold, Edward S.; Thomas, Roger E.
1980-01-01
The relationship between sexual experience and contraceptive attitudinal responses to a birth control film is examined. Significant group differences were found regarding reinforcement of sexual attitudes but not for contraceptive attitudes. (JMF)
Belgrave, F Z; Van Oss Marin, B; Chambers, D B
2000-08-01
The role of cultural factors in explaining sexual attitudes among African American urban girls, aged 10-13 years, was investigated in this study. The authors predicted that girls with higher school interest, family cohesion, religiosity, and behavioral self-esteem would endorse less risky sexual attitudes. Also, older girls were expected to have more risky sexual attitudes than younger girls, and girls from 1- rather than 2-parent households were expected to have more risky sexual attitudes. The authors hypothesized that ethnic identity and gender role orientations would contribute to explaining variability in sexual attitudes after controlling for contextual and intrapersonal variables. A questionnaire containing measures of the study constructs was administered to 214 girls who were participants in a substance abuse prevention program. Pretest data were used in analyses. A final regression model accounted for 23% of the variance in sexual attitudes. Age and behavioral self-esteem were significant predictors, with younger teens and teens with higher behavioral self-esteem having less risky sexual attitudes. Cultural variables contributed to explaining variation in sexual attitudes after other variables were controlled for. Higher levels of ethnic identity were associated with less risky sexual attitudes. A masculine gender role orientation was associated with more risky sexual attitudes.
NASA Technical Reports Server (NTRS)
Notti, J. E.; Cormack, A., III; Schmill, W. C.
1974-01-01
An Integrated Power/Attitude Control System (IPACS) concept consisting of an array of spinning flywheels, with or without gimbals, capable of performing the dual function of power storage and generation, as well as attitude control has been investigated. This system provides attitude control through momentum storage, and replaces the storage batteries onboard the spacecraft. The results of the investigation are presented in two volumes. The trade-off studies performed to establish the feasibility, cost effectiveness, required level of development, and boundaries of application of IPACS to a wide variety of spacecraft are discussed. The conceptual designs for a free-flying research application module (RAM), and for a tracking and data relay satellite (TDRS) are presented. Results from dynamic analyses and simulations of the IPACS conceptual designs are included.
Attitude: A Component of Competent Performance.
ERIC Educational Resources Information Center
Meussling, Vonne
The findings of a survey of attitude studies to determine the effect of students' attitudes on communication competence as they enter the work force and develop their careers are reported in this paper. The paper explains how attitude improvement is an effective management tool in controlling costly absenteeism, output, job productivity, work…
Lino, Stephanie; Marshak, Helen Hopp; Herring, R Patti; Belliard, Juan Carlos; Hilliard, Charles; Campbell, Danielle; Montgomery, Susanne
2014-04-01
This cross-sectional study investigated whether the theory of planned behavior (TPB) constructs: attitudes, subjective norms, and perceived behavioral control were related to intention of dietary supplements use among African-American women living with Human Immunodeficiency Virus and/or Acquired Immune Deficiency Syndrome (HIV/AIDS). A closed-ended questionnaire based on the TPB was utilized to explore the use of dietary supplements among a cohort of 153 HIV-positive African-American women. Overall, 45% of the respondents used dietary supplements to manage/control their HIV. Combined, attitudes, subjective norms and perceived behavioral control were significant predictors of intention toward dietary supplement use (69% of the variance explained, p<0.0001). Attitudes (β=0.23, p<0.001) and perceived behavioral control (β=0.45, p<0.0001) were found to be significant independent predictors of intention. Behavioral intention and proximal TPB constructs (attitudes, subjective norms, and perceived behavioral control), as well as their underlying beliefs about dietary supplements use, were all found to be significantly more positive in users of dietary supplements compared to non-users (p<0.001). Results showed that attitudes, subjective norms and perceived behavioral control are important predictors in the intention to use dietary supplements for control of HIV among African-American women. Implications from this study suggest that the TPB can be used to better identify and understand salient beliefs that surround intentions to use alternative therapies for management of disease. These beliefs can be used to develop interventions surrounding HIV treatment and care. Copyright © 2014 Elsevier Ltd. All rights reserved.
Bestman, Amy; Thomas, Samantha; Randle, Melanie; Pitt, Hannah
2017-05-08
This research sought to explore whether children's visual and auditory exposure to Electronic Gambling Machines (EGMs) in community clubs contributed to shaping their attitudes towards these types of potentially harmful gambling products. This research also examined children's knowledge of EGM behaviours in adults within their social networks. Qualitative interviews were conducted with a convenience sample of 45 children in a regional area of New South Wales, Australia. All children had attended a club that contained gambling products in the previous 12 months. Face to face, semi-structured interviews explored a range of themes including recall of and attitudes towards EGMs. Data were analysed using thematic techniques. Four social learning theory concepts-attentional, retention, reinforcement and reproduction-were used to explore the range of processes that influenced children's attitudes towards EGMs. In relation to attentional factors, children recalled having seen EGMs in clubs, including where they were located, auditory stimuli and the physical appearance of EGMs. Children also retained information about the behaviours associated with gambling on EGMs, most prominently why adults gamble on these machines. Attitudes towards EGMs were reinforced by the child's knowledge of adults EGM behaviours. Some older children's attitudes were positively reinforced by the perception that profits from the machines would go back to their local sporting teams. Finally, while some children expressed a desire to reproduce EGM behaviours when they were older, others were concerned about the negative consequences of engaging in this type of gambling. Despite policies that try to prevent children's exposure to EGMs in community venues, children have peripheral exposure to EGMs within these environments. This exposure and children's awareness of gambling behaviours of adults appear to play a role in shaping their attitudes towards EGMs. While further research should explore the range of other ancillary factors that contribute to children's knowledge about these machines, policy makers should consider more effective strategies to prevent children from being exposed to EGMs in community venues.
ERIC Educational Resources Information Center
Hunter, Karen
1988-01-01
Proposes that academic librarians and publishers should view themselves as partners rather than adversaries. Following a discussion of premises, problems, and attitudes related to librarian-publisher cooperation, several areas for joint development are suggested: new products and services; CD-ROM; electronic document delivery; scholarly book…
ERIC Educational Resources Information Center
Tang, Michael T.; Tzeng, Gwo-Hshiung
In this paper, the impacts of Electronic Commerce (EC) on the international marketing strategies of information service industries are studied. In seeking to blend humanistic concerns in this research with technological development by addressing challenges for deterministic attitudes, the paper examines critical environmental factors relevant to…
Spacecraft attitude control using neuro-fuzzy approximation of the optimal controllers
NASA Astrophysics Data System (ADS)
Kim, Sung-Woo; Park, Sang-Young; Park, Chandeok
2016-01-01
In this study, a neuro-fuzzy controller (NFC) was developed for spacecraft attitude control to mitigate large computational load of the state-dependent Riccati equation (SDRE) controller. The NFC was developed by training a neuro-fuzzy network to approximate the SDRE controller. The stability of the NFC was numerically verified using a Lyapunov-based method, and the performance of the controller was analyzed in terms of approximation ability, steady-state error, cost, and execution time. The simulations and test results indicate that the developed NFC efficiently approximates the SDRE controller, with asymptotic stability in a bounded region of angular velocity encompassing the operational range of rapid-attitude maneuvers. In addition, it was shown that an approximated optimal feedback controller can be designed successfully through neuro-fuzzy approximation of the optimal open-loop controller.
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.
Matlow, Anne G; Wray, Rick; Richardson, Susan E
2012-04-01
Hospital environmental service workers (ESWs) play an important role in interrupting the chain of infection because the environment is a reservoir for nosocomial pathogens. Improving ESWs' knowledge through education has been shown to improve ESW cleaning, but the behavioral determinants of their work have not been studied. Understanding and targeting ESWs' attitudes and beliefs may inform strategies to improve environmental cleaning. With the theory of planned behavior as framework, we used questionnaires and focus groups to examine intensive care unit ESWs' attitudes, beliefs [behavioral, normative, and control], and control) and intent about their job. Baseline quantitative microbial cultures of high-touch services were performed before and after cleaning. After an educational intervention addressing their attitudes, beliefs, and general infection control knowledge, attitudes, beliefs, and microbial contamination were reassessed. Beliefs were uniformly strong (4.5/5-5/5), and normative beliefs correlated best with intent to clean (R(2) = 0.3). Themes elicited from the focus groups included "me versus them," lack of appreciation, pride in work, and "if it were me." The rate of environmental contamination was significantly improved after the intervention (P = .0074 vs P = .0023, respectively); the measured relationship among attitudes, beliefs, and intent was not significantly changed. ESWs' attitudes and beliefs about their job may impact their intent to clean and in turn the effectiveness of their efforts. Understanding and addressing these attitudes and beliefs can be used to inform strategies for sustained improvement of environmental cleaning. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.
Physicians' Use of and Attitudes Toward Electronic Mail for Patient Communication
Gaster, Barak; Knight, Christopher L; DeWitt, Dawn E; Sheffield, John V L; Assefi, Nassim P; Buchwald, Dedra
2003-01-01
To assess physicians' use of and attitudes toward electronic mail (e-mail) for patient communication, we conducted a mail-in survey of physicians who see patients in outpatient clinics affiliated with a large academic medical center (N = 283). Seventy-two percent of physicians reported using e-mail to communicate with patients, averaging 7.7 e-mails from patients per month. The lowest level of use was by community-based primary care physicians (odds ratio, 0.22; 95% confidence interval, 0.08 to 0.59). Those physicians who reported using e-mail with patients reported high satisfaction with its use. Although physicians were concerned about the confidentiality of e-mail, few discussed this issue with patients. PMID:12795738
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.
Birth Control and Low-Income Mexican-American Women: The Impact of Three Values.
ERIC Educational Resources Information Center
Ortiz, Silvia; Casas, Jesus Manuel
1990-01-01
Assesses relationship between Mexican-American women's birth-control attitudes, knowledge, and usage, and values of motherhood, male dominance, and sexual expression. Multiple regression analysis links contraception attitudes with traditional values, regardless of acculturation. Establishes positive link between birth-control use and traditional…
Afsari, Atousa; Mirghafourvand, Mojgan; Valizadeh, Sousan; Abbasnezhadeh, Massomeh; Galshi, Mina; Fatahi, Samira
2017-04-01
The attitude of a girl toward her menstruation and puberty has a considerable impact on her role during motherhood, social adjustment, and future marital life. This study was conducted in 2014 with the aim of comparing the effects of educating mothers and girls on the attitudes of adolescent girls of Tabriz City, Iran, towards puberty health. This randomized control clinical trial was conducted on 364 adolescent girls who experienced menstruation. Twelve schools were selected randomly among 107 secondary schools for girls. One-third of the students of each school were selected randomly using a table of random numbers and socio-demographic and each participant was asked to answer the attitude questionnaires. The schools were randomly allocated to the groups of mother's education, girl's education, and no-intervention. The attitude questionnaire was filled out by the participants again 2 months after intervention. The general linear model, in which the baseline values were controlled, was employed to compare the scores of the three groups after the intervention. No significant differences were observed among the three groups in terms of the attitude score before intervention (p>0.05). Attitude score improvement after intervention in the girl's education group was significantly higher than the one of both mother's education (adjusted mean difference [AMD]: 1.8; [95% confidence interval (CI): 0.4-1.3]) and no-intervention groups (AMD: 1.3; [95% CI: 0.0-2.6]) by controlling the attitude score before intervention. Based on the findings, it is more effective to educate girls directly about puberty health to improve adolescent girls' attitudes than educating mothers and asking them to transfer information to the girls. Nevertheless, studies with longer training period and follow-up are proposed to determine the effects of educating girls (through their mothers) on their attitudes about puberty health.
Finite-time fault tolerant attitude stabilization control for rigid spacecraft.
Huo, Xing; Hu, Qinglei; Xiao, Bing
2014-03-01
A sliding mode based finite-time control scheme is presented to address the problem of attitude stabilization for rigid spacecraft in the presence of actuator fault and external disturbances. More specifically, a nonlinear observer is first proposed to reconstruct the amplitude of actuator faults and external disturbances. It is proved that precise reconstruction with zero observer error is achieved in finite time. Then, together with the system states, the reconstructed information is used to synthesize a nonsingular terminal sliding mode attitude controller. The attitude and the angular velocity are asymptotically governed to zero with finite-time convergence. A numerical example is presented to demonstrate the effectiveness of the proposed scheme. © 2013 Published by ISA on behalf of ISA.
Straker, Leon M; Campbell, Amity C; Jensen, Lyn M; Metcalf, Deborah R; Smith, Anne J; Abbott, Rebecca A; Pollock, Clare M; Piek, Jan P
2011-08-18
A healthy start to life requires adequate motor development and physical activity participation. Currently 5-15% of children have impaired motor development without any obvious disorder. These children are at greater risk of obesity, musculoskeletal disorders, low social confidence and poor mental health. Traditional electronic game use may impact on motor development and physical activity creating a vicious cycle. However new virtual reality (VR) game interfaces may provide motor experiences that enhance motor development and lead to an increase in motor coordination and better physical activity and mental health outcomes. VR games are beginning to be used for rehabilitation, however there is no reported trial of the impact of these games on motor coordination in children with developmental coordination disorder. This cross-over randomised and controlled trial will examine whether motor coordination is enhanced by access to active electronic games and whether daily activity, attitudes to physical activity and mental health are also enhanced. Thirty children aged 10-12 years with poor motor coordination (≤ 15th percentile) will be recruited and randomised to a balanced ordering of 'no active electronic games' and 'active electronic games'. Each child will participate in both conditions for 16 weeks, and be assessed prior to participation and at the end of each condition. The primary outcome is motor coordination, assessed by kinematic and kinetic motion analysis laboratory measures. Physical activity and sedentary behaviour will be assessed by accelerometry, coordination in daily life by parent report questionnaire and attitudes to physical activity, self-confidence, anxiety and depressed mood will be assessed by self report questionnaire. A sample of 30 will provide a power of > 0.9 for detecting a 5 point difference in motor coordination on the MABC-2 TIS scale (mean 17, sd = 5). This is the first trial to examine the impact of new virtual reality games on motor coordination in children with developmental coordination disorder. The findings will provide critical information to understand whether these electronic games can be used to have a positive impact on the physical and mental health of these children. Given the importance of adequate motor coordination, physical activity and mental health in childhood, this project can inform interventions which could have a profound impact on the long term health of this group of children. Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000400965.
2011-01-01
Background A healthy start to life requires adequate motor development and physical activity participation. Currently 5-15% of children have impaired motor development without any obvious disorder. These children are at greater risk of obesity, musculoskeletal disorders, low social confidence and poor mental health. Traditional electronic game use may impact on motor development and physical activity creating a vicious cycle. However new virtual reality (VR) game interfaces may provide motor experiences that enhance motor development and lead to an increase in motor coordination and better physical activity and mental health outcomes. VR games are beginning to be used for rehabilitation, however there is no reported trial of the impact of these games on motor coordination in children with developmental coordination disorder. Methods This cross-over randomised and controlled trial will examine whether motor coordination is enhanced by access to active electronic games and whether daily activity, attitudes to physical activity and mental health are also enhanced. Thirty children aged 10-12 years with poor motor coordination (≤ 15th percentile) will be recruited and randomised to a balanced ordering of 'no active electronic games' and 'active electronic games'. Each child will participate in both conditions for 16 weeks, and be assessed prior to participation and at the end of each condition. The primary outcome is motor coordination, assessed by kinematic and kinetic motion analysis laboratory measures. Physical activity and sedentary behaviour will be assessed by accelerometry, coordination in daily life by parent report questionnaire and attitudes to physical activity, self-confidence, anxiety and depressed mood will be assessed by self report questionnaire. A sample of 30 will provide a power of > 0.9 for detecting a 5 point difference in motor coordination on the MABC-2 TIS scale (mean 17, sd = 5). Discussion This is the first trial to examine the impact of new virtual reality games on motor coordination in children with developmental coordination disorder. The findings will provide critical information to understand whether these electronic games can be used to have a positive impact on the physical and mental health of these children. Given the importance of adequate motor coordination, physical activity and mental health in childhood, this project can inform interventions which could have a profound impact on the long term health of this group of children. Trial registration Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12611000400965 PMID:21851587
Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan
2017-01-01
Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices.
Wang, Yan; Wang, Guosen; Zhang, Dingyuan; Wang, Lei; Cui, Xianghua; Zhu, Jinglei; Fang, Yuan
2017-01-01
Evaluative conditioning (EC) procedures can be used to form and change attitudes toward a wide variety of objects. The current study examined the effects of a negative EC procedure on attitudes toward chocolate, and whether it influenced chocolate evaluation and consumption. Participants were randomly assigned to the experimental condition in which chocolate images were paired with negative stimuli, or the control condition in which chocolate images were randomly paired with positive stimuli (50%) and negative stimuli (50%). Explicit and implicit attitudes toward chocolate images were collected. During an ostensible taste test, chocolate evaluation and consumption were assessed. Results revealed that compared to participants in the control condition, participants in the experimental condition showed more negative explicit and implicit attitudes toward chocolate images and evaluated chocolate more negatively during the taste test. However, chocolate consumption did not differ between experimental and control conditions. These findings suggest that pairing chocolate with negative stimuli can influence attitudes toward chocolate, though behavioral effects are absent. Intervention applications of EC provide avenues for future research and practices. PMID:28900409
Debris measure subsystem of the nanosatellite IRECIN
NASA Astrophysics Data System (ADS)
Ferrante, M.; di Ciolo, L.; Ortenzi, A.; Petrozzi, M.; del Re, V.
2003-09-01
The on board resources, needed to perform the mission tasks, are very limited in nano-satellites. This paper proposes an Electronic real-time system that acquires space debris measures. It uses a piezo-electric sensor. The described device is a subsystem on board of the IRECIN nanosatellite composed mainly by a r.i.s.c. microprocessor, an electronic part that interfaces to the debris sensor in order to provide a low noise electrical and suitable range to ADC 12 bit converter, and finally a memory in order to store the data. The microprocessor handles the Debris Measure System measuring the impacts number, their intensity and storing their waves form. This subsystem is able to communicate with the other IRECIN subsystems through I2C Bus and principally with the "Main Microprocessor" subsystem allowing the data download directly to the Ground Station. Moreover this subsystem lets free the "Main Microprocessor Board" from the management and charge of debris data. All electronic components are SMD technology in order to reduce weight and size. The realized Electronic board are completely developed, realized and tested at the Vitrociset S.P.A. under control of Research and Development Group. The proposed system is implemented on the IRECIN, a modular nanosatellite weighting less than 1.5 kg, constituted by sixteen external sides with surface-mounted solar cells and three internal Al plates, kept together by four steel bars. Lithium-ions batteries are added for eclipse operations. Attitude is determined by two three-axis magnetometers and the solar panels data. Control is provided by an active magnetic control system. The spacecraft will be spin-stabilized with the spin-axis normal to the orbit. debris and micrometeoroids mass and velocity.
Attitude Control Propulsion Components, Volume 2
NASA Technical Reports Server (NTRS)
1974-01-01
Attitude control propulsion components are described, including hydrazine thrusters, hydrazine thruster and cold gas jet valves, and pressure and temperature transducers. Component-ordered data are presented in tabular form; the manufacturer and specific space program are included.
Field-of-View Guiding Camera on the HISAKI (SPRINT-A) Satellite
NASA Astrophysics Data System (ADS)
Yamazaki, A.; Tsuchiya, F.; Sakanoi, T.; Uemizu, K.; Yoshioka, K.; Murakami, G.; Kagitani, M.; Kasaba, Y.; Yoshikawa, I.; Terada, N.; Kimura, T.; Sakai, S.; Nakaya, K.; Fukuda, S.; Sawai, S.
2014-11-01
HISAKI (SPRINT-A) satellite is an earth-orbiting Extreme UltraViolet (EUV) spectroscopic mission and launched on 14 Sep. 2013 by the launch vehicle Epsilon-1. Extreme ultraviolet spectroscope (EXCEED) onboard the satellite will investigate plasma dynamics in Jupiter's inner magnetosphere and atmospheric escape from Venus and Mars. EUV spectroscopy is useful to measure electron density and temperature and ion composition in plasma environment. EXCEED also has an advantage to measure spatial distribution of plasmas around the planets. To measure radial plasma distribution in the Jovian inner magnetosphere and plasma emissions from ionosphere, exosphere and tail separately (for Venus and Mars), the pointing accuracy of the spectroscope should be smaller than spatial structures of interest (20 arc-seconds). For satellites in the low earth orbit (LEO), the pointing displacement is generally caused by change of alignment between the satellite bus module and the telescope due to the changing thermal inputs from the Sun and Earth. The HISAKI satellite is designed to compensate the displacement by tracking the target with using a Field-Of-View (FOV) guiding camera. Initial checkout of the attitude control for the EXCEED observation shows that pointing accuracy kept within 2 arc-seconds in a case of "track mode" which is used for Jupiter observation. For observations of Mercury, Venus, Mars, and Saturn, the entire disk will be guided inside slit to observe plasma around the planets. Since the FOV camera does not capture the disk in this case, the satellite uses a star tracker (STT) to hold the attitude ("hold mode"). Pointing accuracy during this mode has been 20-25 arc-seconds. It has been confirmed that the attitude control works well as designed.
Speed-constrained three-axes attitude control using kinematic steering
NASA Astrophysics Data System (ADS)
Schaub, Hanspeter; Piggott, Scott
2018-06-01
Spacecraft attitude control solutions typically are torque-level algorithms that simultaneously control both the attitude and angular velocity tracking errors. In contrast, robotic control solutions are kinematic steering commands where rates are treated as the control variable, and a servo-tracking control subsystem is present to achieve the desired control rates. In this paper kinematic attitude steering controls are developed where an outer control loop establishes a desired angular response history to a tracking error, and an inner control loop tracks the commanded body angular rates. The overall stability relies on the separation principle of the inner and outer control loops which must have sufficiently different response time scales. The benefit is that the outer steering law response can be readily shaped to a desired behavior, such as limiting the approach angular velocity when a large tracking error is corrected. A Modified Rodrigues Parameters implementation is presented that smoothly saturates the speed response. A robust nonlinear body rate servo loop is developed which includes integral feedback. This approach provides a convenient modular framework that makes it simple to interchange outer and inner control loops to readily setup new control implementations. Numerical simulations illustrate the expected performance for an aggressive reorientation maneuver subject to an unknown external torque.
Deep Space 1 Ion Engine Completed a 3-Year Journey
NASA Technical Reports Server (NTRS)
Sovey, James S.; Patterson, Michael J.; Rawlin, Vincent K.; Hamley, John A.
2001-01-01
A xenon ion engine and power processor system, which was developed by the NASA Glenn Research Center in partnership with the Jet Propulsion Laboratory and Boeing Electron Dynamic Devices, completed nearly 3 years of operation aboard the Deep Space 1 spacecraft. The 2.3-kW ion engine, which provided primary propulsion and two-axis attitude control, thrusted for more than 16,000 hr and consumed more than 70 kg of xenon propellant. The Deep Space 1 spacecraft was launched on October 24, 1998, to validate 12 futuristic technologies, including the ion-propulsion system. After the technology validation process was successfully completed, the Deep Space 1 spacecraft flew by the small asteroid Braille on July 29, 1999. The final objective of this mission was to encounter the active comet Borrelly, which is about 6 miles long. The ion engine was on a thrusting schedule to navigate the Deep Space 1 spacecraft to within 1400 miles of the comet. Since the hydrazine used for spacecraft attitude control was in short supply, the ion engine also provided two-axis attitude control to conserve the hydrazine supply for the Borrelly encounter. The comet encounter took place on September 22, 2001. Dr. Marc Rayman, project manager of Deep Space 1 at the Jet Propulsion Laboratory said, "Deep Space 1 plunged into the heart of the comet Borrelly and has lived to tell every detail of its spinetingling adventure! The images are even better than the impressive images of comet Halley taken by Europe's Giotto spacecraft in 1986." The Deep Space 1 mission, which successfully tested the 12 high-risk, advanced technologies and captured the best images ever taken of a comet, was voluntarily terminated on December 18, 2001. The successful demonstration of the 2-kW-class ion propulsion system technology is now providing mission planners with off-the-shelf flight hardware. Higher power, next generation ion propulsion systems are being developed for large flagship missions, such as outer planet explorers and sample-return missions.
NASA Technical Reports Server (NTRS)
Forcey, W.; Minnie, C. R.; Defazio, R. L.
1995-01-01
The Geostationary Operational Environmental Satellite (GOES)-8 experienced a series of orbital perturbations from autonomous attitude control thrusting before perigee raising maneuvers. These perturbations influenced differential correction orbital state solutions determined by the Goddard Space Flight Center (GSFC) Goddard Trajectory Determination System (GTDS). The maneuvers induced significant variations in the converged state vector for solutions using increasingly longer tracking data spans. These solutions were used for planning perigee maneuvers as well as initial estimates for orbit solutions used to evaluate the effectiveness of the perigee raising maneuvers. This paper discusses models for the incorporation of attitude thrust effects into the orbit determination process. Results from definitive attitude solutions are modeled as impulsive thrusts in orbit determination solutions created for GOES-8 mission support. Due to the attitude orientation of GOES-8, analysis results are presented that attempt to absorb the effects of attitude thrusting by including a solution for the coefficient of reflectivity, C(R). Models to represent the attitude maneuvers are tested against orbit determination solutions generated during real-time support of the GOES-8 mission. The modeling techniques discussed in this investigation offer benefits to the remaining missions in the GOES NEXT series. Similar missions with large autonomous attitude control thrusting, such as the Solar and Heliospheric Observatory (SOHO) spacecraft and the INTELSAT series, may also benefit from these results.
Robust attitude control design for spacecraft under assigned velocity and control constraints.
Hu, Qinglei; Li, Bo; Zhang, Youmin
2013-07-01
A novel robust nonlinear control design under the constraints of assigned velocity and actuator torque is investigated for attitude stabilization of a rigid spacecraft. More specifically, a nonlinear feedback control is firstly developed by explicitly taking into account the constraints on individual angular velocity components as well as external disturbances. Considering further the actuator misalignments and magnitude deviation, a modified robust least-squares based control allocator is employed to deal with the problem of distributing the previously designed three-axis moments over the available actuators, in which the focus of this control allocation is to find the optimal control vector of actuators by minimizing the worst-case residual error using programming algorithms. The attitude control performance using the controller structure is evaluated through a numerical example. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.
High speed reaction wheels for satellite attitude control and energy storage
NASA Technical Reports Server (NTRS)
Studer, P.; Rodriguez, E.
1985-01-01
The combination of spacecraft attitude control and energy storage (ACES) functions in common hardware, to synergistically maintain three-axis attitude control while supplying electrical power during earth orbital eclipses, allows the generation of control torques by high rotating speed wheels that react against the spacecraft structure via a high efficiency bidirectional energy conversion motor/generator. An ACES system encompasses a minimum of four wheels, controlling power and the three torque vectors. Attention is given to the realization of such a system with composite flywheel rotors that yield high energy density, magnetic suspension technology yielding low losses at high rotational speeds, and an ironless armature permanent magnet motor/generator yielding high energy conversion efficiency.
Grasp Assist Device with Automatic Mode Control Logic
NASA Technical Reports Server (NTRS)
Laske, Evan (Inventor); Davis, Donald R. (Inventor); Ihrke, Chris A. (Inventor)
2018-01-01
A system includes a glove, sensors, actuator assemblies, and controller. The sensors include load sensors which measure an actual grasping force and attitude sensors which determine a glove attitude. The actuator assembly provides a grasp assist force to the glove. Respective locations of work cells in the work environment and permitted work tasks for each work cell are programmed into the controller. The controller detects the glove location and attitude. A work task is selected by the controller for the location. The controller calculates a required grasp assist force using measured actual grasping forces from the load sensors. The required grasp assist force is applied via the glove using the actuator assembly to thereby assist the operator in performing the identified work task.
Latent interaction effects in the theory of planned behaviour applied to quitting smoking.
Hukkelberg, Silje Sommer; Hagtvet, Knut A; Kovac, Velibor Bobo
2014-02-01
This study applies three latent interaction models in the theory of planned behaviour (TPB; Ajzen, 1988, Attitudes, personality, and behavior. Homewood, IL: Dorsey Press; Ajzen, 1991, Organ. Behav. Hum. Decis. Process., 50, 179) to quitting smoking: (1) attitude × perceived behavioural control on intention; (2) subjective norms (SN) × attitude on intention; and (3) perceived behavioural control × intention on quitting behaviour. The data derive from a longitudinal Internet survey of 939 smokers aged 15-74 over a period of 4 months. Latent interaction effects were estimated using the double-mean-centred unconstrained approach (Lin et al., 2010, Struct. Equ. Modeling, 17, 374) in LISREL. Attitude × SN and attitude × perceived behavioural control both showed a significant interaction effect on intention. No significant interaction effect was found for perceived behavioural control × intention on quitting. The latent interaction approach is a useful method for investigating specific conditions between TPB components in the context of quitting behaviour. Theoretical and practical implications of the results are discussed. © 2013 The British Psychological Society.
Instrument Attitude Precision Control
NASA Technical Reports Server (NTRS)
Juang, Jer-Nan
2004-01-01
A novel approach is presented in this paper to analyze attitude precision and control for an instrument gimbaled to a spacecraft subject to an internal disturbance caused by a moving component inside the instrument. Nonlinear differential equations of motion for some sample cases are derived and solved analytically to gain insight into the influence of the disturbance on the attitude pointing error. A simple control law is developed to eliminate the instrument pointing error caused by the internal disturbance. Several cases are presented to demonstrate and verify the concept presented in this paper.
AAS/GSFC 13th International Symposium on Space Flight Dynamics. Volume 1
NASA Technical Reports Server (NTRS)
Stengle, Tom (Editor)
1998-01-01
This conference proceedings preprint includes papers and abstracts presented at the 13th International Symposium on Space Flight Dynamics. Cosponsored by American Astronautical Society and the Guidance, Navigation and Control Center of the 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 dynamics; and mission design.
Attitude dynamics and control of spacecraft with a partially filled liquid tank and flexible panels
NASA Astrophysics Data System (ADS)
Liu, Feng; Yue, Baozeng; Zhao, Liangyu
2018-02-01
A liquid-filled flexible spacecraft is essentially a time-variant fully-coupled system, whose dynamics characteristics are closely associated with its motion features. This paper focuses on the mathematical modelling and attitude control of the spacecraft coupled with fuel sloshing dynamics and flexible solar panels vibration. The slosh motion is represented by a spherical pendulum, whose motion description method is improved by using split variable operation. Benefiting from this improvement, the nonlinear lateral sloshing and the rotary sloshing as well as the rigid motion of a liquid respect to the spacecraft can be approximately described. The assumed modes discretization method has been adopted to approximate the elastic displacements of the attached panels, and the coupled dynamics is derived by using the Lagrangian formulation. A variable substitution method is proposed to obtain the apparently-uncoupled mathematical model of the rigid-flexible-liquid spacecraft. After linearization, this model can be directly used for designing Lyapunov output-feedback attitude controller (OFAC). With only torque actuators, and attitude and rate sensors installed, this kind of attitude controller, as simulation results show, is capable of not only bringing the spacecraft to the desired orientation, but also suppressing the effect of flex and slosh on the attitude motion of the spacecraft.
Development of a hardware-in-loop attitude control simulator for a CubeSat satellite
NASA Astrophysics Data System (ADS)
Tapsawat, Wittawat; Sangpet, Teerawat; Kuntanapreeda, Suwat
2018-01-01
Attitude control is an important part in satellite on-orbit operation. It greatly affects the performance of satellites. Testing of an attitude determination and control subsystem (ADCS) is very challenging since it might require attitude dynamics and space environment in the orbit. This paper develops a low-cost hardware-in-loop (HIL) simulator for testing an ADCS of a CubeSat satellite. The simulator consists of a numerical simulation part, a hardware part, and a HIL interface hardware unit. The numerical simulation part includes orbital dynamics, attitude dynamics and Earth’s magnetic field. The hardware part is the real ADCS board of the satellite. The simulation part outputs satellite’s angular velocity and geomagnetic field information to the HIL interface hardware. Then, based on this information, the HIL interface hardware generates I2C signals mimicking the signals of the on-board rate-gyros and magnetometers and consequently outputs the signals to the ADCS board. The ADCS board reads the rate-gyro and magnetometer signals, calculates control signals, and drives the attitude actuators which are three magnetic torquers (MTQs). The responses of the MTQs sensed by a separated magnetometer are feedback to the numerical simulation part completing the HIL simulation loop. Experimental studies are conducted to demonstrate the feasibility and effectiveness of the simulator.
White, Katherine M; Starfelt, Louise C; Young, Ross McD; Hawkes, Anna L; Cleary, Catherine; Leske, Stuart; Wihardjo, Kylie
2015-03-01
To evaluate the effectiveness of a single-session online theory of planned behaviour (TPB)-based intervention to improve sun-protective attitudes and behaviour among Australian adults. Australian adults (N=534; 38.7% males; Mage=39.3 years) from major cities (80.9%), regional (17.6%) and remote areas (1.5%) were recruited and randomly allocated to an intervention (N=265) and information only group (N=267). The online intervention focused on fostering positive attitudes, perceptions of normative support, and control perceptions for sun protection. Participants completed questionnaires assessing standard TPB measures (attitude, subjective norm, perceived behavioural control, intention, behaviour) and extended TPB constructs of group norm (friends, family), personal norm, and image norm, pre-intervention (Time 1) and one week (Time 2) and one month post-intervention (Time 3). Repeated Measures Multivariate Analysis of Variance tested intervention effects across time. Intervention participants reported more positive attitudes towards sun protection and used sun-protective measures more often in the subsequent month than participants receiving information only. The intervention effects on control perceptions and norms were non-significant. A theory-based online intervention fostering more favourable attitudes towards sun safety can increase sun protection attitudes and self-reported behaviour among Australian adults in the short term. Copyright © 2015 Elsevier Inc. All rights reserved.
Reconfigurable modular computer networks for spacecraft on-board processing
NASA Technical Reports Server (NTRS)
Rennels, D. A.
1978-01-01
The core electronics subsystems on unmanned spacecraft, which have been sent over the last 20 years to investigate the moon, Mars, Venus, and Mercury, have progressed through an evolution from simple fixed controllers and analog computers in the 1960's to general-purpose digital computers in current designs. This evolution is now moving in the direction of distributed computer networks. Current Voyager spacecraft already use three on-board computers. One is used to store commands and provide overall spacecraft management. Another is used for instrument control and telemetry collection, and the third computer is used for attitude control and scientific instrument pointing. An examination of the control logic in the instruments shows that, for many, it is cost-effective to replace the sequencing logic with a microcomputer. The Unified Data System architecture considered consists of a set of standard microcomputers connected by several redundant buses. A typical self-checking computer module will contain 23 RAMs, two microprocessors, one memory interface, three bus interfaces, and one core building block.
Results of solar electric thrust vector control system design, development and tests
NASA Technical Reports Server (NTRS)
Fleischer, G. E.
1973-01-01
Efforts to develop and test a thrust vector control system TVCS for a solar-energy-powered ion engine array are described. The results of solar electric propulsion system technology (SEPST) III real-time tests of present versions of TVCS hardware in combination with computer-simulated attitude dynamics of a solar electric multi-mission spacecraft (SEMMS) Phase A-type spacecraft configuration are summarized. Work on an improved solar electric TVCS, based on the use of a state estimator, is described. SEPST III tests of TVCS hardware have generally proved successful and dynamic response of the system is close to predictions. It appears that, if TVCS electronic hardware can be effectively replaced by control computer software, a significant advantage in control capability and flexibility can be gained in future developmental testing, with practical implications for flight systems as well. Finally, it is concluded from computer simulations that TVCS stabilization using rate estimation promises a substantial performance improvement over the present design.
Internal-External Locus of Control and Attitude Toward Disability.
ERIC Educational Resources Information Center
MacDonald, A. P.
The relationship between internal-external locus of control and attitude and reaction toward disability is discussed. Apart from examining the relevant research literature, findings are presented which support the hypothesis that those non-disabled who have external control orientations are more threatened by physical disabilities (vis., internal…
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…
Laboratory Control System's Effects on Student Achievement and Attitudes
ERIC Educational Resources Information Center
Cicek, Fatma Gozalan; Taspinar, Mehmet
2016-01-01
Problem Statement: The current study investigates whether the learning environment designed based on the laboratory control system affects the academic achievement, the attitude toward the learning-teaching process and the retention of the students in computer education. Purpose of Study: The study aims to identify the laboratory control system…
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.
New controlled environment vitrification system for preparing wet samples for cryo-SEM.
Ge, H; Suszynski, W J; Davis, H T; Scriven, L E
2008-01-01
A new controlled environment vitrification system (CEVS) has been designed and constructed to facilitate examination by cryogenic scanning electron microscopy (Cryo-SEM) of initial suspension state and of microstructure development in latex, latex-composite and other coatings while they still contain solvent. The new system has a main chamber with provisions for coating as well as drying, and for well-controlled plunging into cryogen. An added subsidiary chamber holds samples for drying or annealing over minutes to days before they are returned to the main chamber and plunged from it. In the main chamber, samples are blade-coated on 5 x 7 mm pieces of silicon wafer and held at selected temperature and humidity for successively longer times, either there or after transfer along a rail into the subsidiary chamber. They are then placed in the sample holder mounted on the plunge rod, so as to permit adjustment of the sample's attitude when it plunges, at controlled speed, into liquid ethane at its freezing point, to a chosen depth, in order to solidify the sample without significant shear or freezing artifacts. The entries of plunging samples and related sample holders into liquid ethane were recorded with a high-speed, high-resolution Photron digital camera. The data were interpreted with a new hypothesis about the width of the band of extremely rapid cooling by deeply subcooled nucleate boiling below the line of entry. Complementary cryo-SEM images revealed that the freezing rate and surface shearing of a sample need to be balanced by adjusting the plunging attitude.
Trajectory tracking control for underactuated stratospheric airship
NASA Astrophysics Data System (ADS)
Zheng, Zewei; Huo, Wei; Wu, Zhe
2012-10-01
Stratospheric airship is a new kind of aerospace system which has attracted worldwide developing interests for its broad application prospects. Based on the trajectory linearization control (TLC) theory, a novel trajectory tracking control method for an underactuated stratospheric airship is presented in this paper. Firstly, the TLC theory is described sketchily, and the dynamic model of the stratospheric airship is introduced with kinematics and dynamics equations. Then, the trajectory tracking control strategy is deduced in detail. The designed control system possesses a cascaded structure which consists of desired attitude calculation, position control loop and attitude control loop. Two sub-loops are designed for the position and attitude control loops, respectively, including the kinematics control loop and dynamics control loop. Stability analysis shows that the controlled closed-loop system is exponentially stable. Finally, simulation results for the stratospheric airship to track typical trajectories are illustrated to verify effectiveness of the proposed approach.
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.
Effecting attitudinal change towards rational drug use.
Singh, T; Natu, M V
1995-01-01
Attitudes of 40 interns towards rational drug use (RDU) were assessed, using a standardized Likert type scale. The assessment was repeated after 4 months to evaluate the effect of usual working conditions of the hospital. After this period, the attitudes had slided towards negative side (p < 0.01). At this point, an intervention in the form of a workshop was provided for half the group while other half served as control. A repeat assessment after another period of 4 months revealed that the attitudes of test group returned towards positive side (p < 0.01) while control group maintained its negative attitudes.
Children and the New 3 Rs (Reduce, Reuse, Recycle): Attitudes toward the Environment.
ERIC Educational Resources Information Center
Malkus, Amy J.; Musser, Lynn M.
This study examined the relationship between children's environmental attitudes and their perceived competence and locus of control. The study sample consisted of 171 children in grades 3, 4, and 5. Children completed the Children's Attitudes Toward the Environment Scale (CATES) and the Janus Environmental Attitudes Scale (JEAS), which assessed…