WorldWideScience

Sample records for attitude control

  1. Optimal magnetic attitude control

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Markley, F.L.

    1999-01-01

    because control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis stabilization of a low earth orbit satellite. The problem of controlling the spacecraft attitude using only magnetic......Magnetic torquing is attractive as means of control for small satellites. The actuation principle is to use the interaction between the earth's magnetic field and a magnetic field generated by a coil set in the satellite. This control principle is inherently time-varying, and difficult to use...

  2. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  3. Satellite Attitude Control System Simulator

    Directory of Open Access Journals (Sweden)

    G.T. Conti

    2008-01-01

    Full Text Available Future space missions will involve satellites with great autonomy and stringent pointing precision, requiring of the Attitude Control Systems (ACS with better performance than before, which is function of the control algorithms implemented on board computers. The difficulties for developing experimental ACS test is to obtain zero gravity and torque free conditions similar to the SCA operate in space. However, prototypes for control algorithms experimental verification are fundamental for space mission success. This paper presents the parameters estimation such as inertia matrix and position of mass centre of a Satellite Attitude Control System Simulator (SACSS, using algorithms based on least square regression and least square recursive methods. Simulations have shown that both methods have estimated the system parameters with small error. However, the least square recursive methods have performance more adequate for the SACSS objectives. The SACSS platform model will be used to do experimental verification of fundamental aspects of the satellite attitude dynamics and design of different attitude control algorithm.

  4. Attitude Control Working Group report

    Science.gov (United States)

    Reid, Daniel F.; Studer, Phillip A.

    1986-01-01

    The goals were to establish the Attitude Control System (ACS) requirements, constraints, technology assessment, technology shortfalls, expected in the year 2000. These were based upon all missions, military and civil, for LEO and GEO. The critical ACS technology issues were identified and ACS programs developed to address these critical issues.

  5. Aircraft Landing and Attitude Control Using Dynamic Matrix Control

    Directory of Open Access Journals (Sweden)

    George Cristian Calugaru

    2017-06-01

    Full Text Available This paper proposes a method for an efficient control of the aircraft landing and attitude through Dynamic Matrix Control. The idea of MPC structures used in aircraft control has been well established during the last few years, but some aspects require further investigation. With this in mind, the paper proposes structures for aircraft landing and aircraft attitude control by using single DMC controllers for landing and respectively one DMC controller for each of the attitude axis (pitch attitude hold, bank angle hold and heading hold. The model used for analysis of the aircraft landing structure is based on the last phase of landing. Also, the model used to illustrate the attitude control is that of a pitch attitude hold system of a N250-100 aircraft. Simulations are performed for a variety of control and prediction horizons, taking into account the possibility of adding a weighting factor for the control actions. Apart from separate studies on step reference variations, for some use cases, a generic reference trajectory is provided as a control purpose of the system. Results show a better performance of the proposed method in terms of control surface transition and protection of the actuators involved and a better time response in stabilizing the aircraft attitude. Overall, the aspects shown ensure an improved aircraft attitude control and landing stabilization.

  6. Experiment D010: Ion sensing attitude control

    Science.gov (United States)

    Sagalyn, R. C.; Smiddy, M.

    1971-01-01

    The feasibility of an attitude control system that uses environmental positive ions and an electrostatic detection system to measure spacecraft pitch and yaw is studied. The secondary objective was to measure the spatial and temporal variations of ambient positively charged particles along the orbital path of the Gemini 10 and 12 spacecrafts. The results proved that the use of a horizon detector in conjunction with pitch and yaw sensors would facilitate complete description of the spacecraft position and attitude. Furthermore, with the addition of a servosystem, the unit could be used as a complete automatic attitude-control system that would be applicable from the lowest satellite altitudes up to at least 10 earth radii. Also, results established that the charge density along the trajectory of the satellite could be determined by transmission of output voltages from the individual electrometers.

  7. Attitude Dynamics and Control of Solar Sails

    Science.gov (United States)

    Sperber, Evan

    Solar sails are space vehicles that rely on solar radiation pressure in order to generate forces for thrust and attitude control torques. They exhibit characteristics such as large moments of inertia, fragility of various system components, and long mission durations that make attitude control a particularly difficult engineering problem. Thrust vector control (TVC) is a family of sailcraft attitude control techniques that is on a short list of strategies thought to be suitable for the primary attitude control of solar sails. Every sailcraft TVC device functions by manipulating the relative locations of the composite mass center (cm) of the sailcraft and the center of pressure (cp) of at least one of its reflectors. Relative displacement of these two points results in body torques that can be used to steer the sailcraft. This dissertation presents a strategy for the large-angle reorientation of a sailcraft using TVC. Two forms of TVC, namely the panel and ballast mass translation methods are well represented in the literature, while rigorous studies regarding a third form, gimballed mass rotation, are conspicuously absent. The gimballed mass method is physically realized by placing a ballast mass, commonly the sailcraft's scientific payload, at the tip of a gimballed boom that has its base fixed at some point on the sailcraft. A TVC algorithm will then strategically manipulate the payload boom's gimbal angles, thereby changing the projection of the sailcraft cm in the plane of the sail. This research demonstrates effective three-axis attitude control of a model sailcraft using numerical simulation of its nonlinear equations of motion. The particular TVC algorithm developed herein involves two phases---the first phase selects appropriate gimbal rates with the objective that the sailcraft be placed in the neighborhood of its target orientation. It was discovered, however that concomitantly minimizing attitude error as well as residual body rate was not possible using

  8. Acquisition and cruise sensing for attitude control

    Science.gov (United States)

    Pace, G. D., Jr.; Schmidt, L. F.

    1977-01-01

    Modified wideangle analog cruise sun sensor coupled with changes in optic attitude correction capabilities, eliminate need of acquisition and sun gate sensors, making on-course navigation of spacecraft flying interplanetary missions less risky and costly. Operational characteristics potentially make system applicable to guidance and control of solar energy collection systems.

  9. TRMM On Orbit Attitude Control System Performance

    Science.gov (United States)

    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.

  10. Low noise spacecraft attitude control systems

    Science.gov (United States)

    Gondhalekar, Vijay; Downer, James R.; Eisenhaure, David B.; Hockney, Richard L.; Johnson, Bruce G.

    1991-01-01

    The authors describe two ongoing research efforts directed at developing advanced spacecraft momentum control flywheels. The first effort is directed at developing low-noise momentum wheels through the use of magnetic bearings. The second effort is directed at demonstrating critical subcomponents of an integrated power and attitude control system (IPACS) that stores energy as kinetic energy in mechanical rotors with the accompanying angular momentum available for attitude control of the spacecraft. The authors describe a ground experiment that was designed to demonstrate an energy storage capability of 1 kWh at a 40 Wh/kg energy density and a 1 kW electrical generation capacity at 85 percent round-trip efficiency and that will allow single-degree-of-freedom gimballing to quantify experimentally the bearing power requirements for processing the flywheel.

  11. Geo satellite attitude and orbit control: fixed orbit control thrasters

    OpenAIRE

    Ermoshkin, Yu; V. Raevsky; Urusov, V.

    2009-01-01

    The paper describes the enhanced application ofhigh-economical electro-jet orbit control thrusters for geostationary satellites; in particular, generation of controlling moments to the benefit of satellite attitude determination and control subsystems in the course of orbit control maneuvers ongoing. The scheme with thrusters fixed on a satellite body is analyzed. Possible orbit control session procedures are proposed on the basis of controlling moments generation. Advantages and disadvantage...

  12. MAP Attitude Control System Design and Analysis

    Science.gov (United States)

    Andrews, S. F.; Campbell, C. E.; Ericsson-Jackson, A. J.; Markley, F. L.; ODonnell, J. R., Jr.

    1997-01-01

    The Microwave Anisotropy Probe (MAP) is a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE) spacecraft. The MAP spacecraft will perform its mission in a Lissajous orbit around the Earth-Sun L(sub 2) Lagrange point to suppress potential instrument disturbances. To make a full-sky map of cosmic microwave background fluctuations, a combination fast spin and slow precession motion will be used. MAP requires a propulsion system to reach L(sub 2), to unload system momentum, and to perform stationkeeping maneuvers once at L(sub 2). A minimum hardware, power and thermal safe control mode must also be provided. Sufficient attitude knowledge must be provided to yield instrument pointing to a standard deviation of 1.8 arc-minutes. The short development time and tight budgets require a new way of designing, simulating, and analyzing the Attitude Control System (ACS). This paper presents the design and analysis of the control system to meet these requirements.

  13. Optimal Sliding Mode Controllers for Attitude Stabilization of Flexible Spacecraft

    Directory of Open Access Journals (Sweden)

    Chutiphon Pukdeboon

    2011-01-01

    Full Text Available The robust optimal attitude control problem for a flexible spacecraft is considered. Two optimal sliding mode control laws that ensure the exponential convergence of the attitude control system are developed. Integral sliding mode control (ISMC is applied to combine the first-order sliding mode with optimal control and is used to control quaternion-based spacecraft attitude manoeuvres with external disturbances and an uncertainty inertia matrix. For the optimal control part the state-dependent Riccati equation (SDRE and optimal Lyapunov techniques are employed to solve the infinite-time nonlinear optimal control problem. The second method of Lyapunov is used to guarantee the stability of the attitude control system under the action of the proposed control laws. An example of multiaxial attitude manoeuvres is presented and simulation results are included to verify the usefulness of the developed controllers.

  14. Magnetorquer Based Attitude Control for a Nanosatellite Testplatform

    NARCIS (Netherlands)

    Torczynski, D.M.; Amini, R.; Massioni, P.

    2010-01-01

    This paper presents the design of an attitude controller for a magnetically actuated nanosatellite. The goal of this attitude control system is to be able to dump excess kinetic rotational energy as well as to point to a rotating frame with an accuracy of five degrees on each axis. From the options

  15. Research on Design of MUH Attitude Stability Augmentation Control System

    Science.gov (United States)

    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.

  16. Adaptive Jacobian Fuzzy Attitude Control for Flexible Spacecraft Combined Attitude and Sun Tracking System

    Science.gov (United States)

    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

  17. On-orbit experience with the HEAO attitude control subsystem

    Science.gov (United States)

    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.

  18. Pulsed Electrogasdynamic Thruster for Attitude Control and Orbit Maneuver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new pulsed electric thruster, named "pulsed electrogasdynamic thruster," for attitude control and orbit maneuver is proposed. In this thruster, propellant gas is...

  19. Pulsed Electrogasdynamic Thruster for Attitude Control and Orbit Maneuver Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In the Phase I program we successfully demonstrated the feasibility of the Pulsed ElectroGasdynamic (PEG) thruster for attitude control and orbital maneuvering. In...

  20. ISS Contingency Attitude Control Recovery Method for Loss of Automatic Thruster Control

    Science.gov (United States)

    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.

  1. Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

    Science.gov (United States)

    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.

  2. Attitude control of Mariner Jupiter-Saturn spacecraft

    Science.gov (United States)

    Bahrami, K. A.

    1976-01-01

    A major challenge of the Mariner Jupiter-Saturn '77 spacecraft was devising a suboptimal attitude controller that could meet the demanding mission requirements. The challenge was met by implementing a discrete stochastic controller for a specially designed onboard computer. The paper describes the design and operation of the controller, based on a simple model of spacecraft dynamics. Two types of cruising modes are considered: inertial cruise, where spacecraft attitude is determined from gyro position outputs, and celestial cruise, where position information is obtained from sun sensors and a star tracker. These two cruise modes under conditions of disturbances were simulated on computer, and the results showed that the controller maintained the spacecraft attitude with low rates. An appendix gives details on the single-step predictor.

  3. Global Observer-Based Attitude Controller Using Direct Inertial Measurements

    Directory of Open Access Journals (Sweden)

    Saâdi Bouhired

    2014-04-01

    Full Text Available In this work, we address the problem of global attitude control using direct inertial measurements. When using direct inertial measurement to observe the rigid body attitude, it is shown that due to a geometrical obstruction, it is impossible to achieve global asymptotic stability. In fact, for a particular initial condition the tracking error quaternion converges to a pure imaginary quaternion formed by an eigenvector of a characteristic matrix related to the inertial constant and known vectors. Our proposition consists of adding a dynamic signal to force the rigid body to escape from such a situation. The proposed observer-based controller is synthesized based on a single Lyapunov function and a stability analysis shows that the controller stabilizes globally and asymptotically the rigid body attitude at the desired one. The effectiveness of the proposed observer-based controller is confirmed by simulation results.

  4. Helicopter attitude stabilization using individual-blade-control

    Science.gov (United States)

    Ham, N. D.

    1984-01-01

    A theoretical study is presented on the application of the Individual-Blade-Control concept to helicopter attitude stabilization. The design of a system controlling blade flapping dynamics, and related testing of the system on a model rotor in the wind tunnel, is described. The control inputs considered are blade pitch changes proportional to blade flapping acceleration, velocity, and displacement. The effect of such a system on helicopter rotor damping-in-pitch, and angle-of-attack stability is then evaluated. It is shown that helicopter attitude stabilization is achieved, with a corresponding improvement in flying qualities.

  5. Reduced Attitude Control of a Robotic Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Bláha Lukáš

    2017-01-01

    Full Text Available This paper deals with stabilization and reduced attitude control of a robotic underwater vehicle. The vehicle is assumed to be able to perform a full stable rotations around all axes in underwater space, that is why the standard bottom-heavy structure is not used. The system preferably uses a vectored-thrust arrangement and is built as an overactuated system, which enables to gain a better robustness and guarantees a stable controlled motion even if some thruster suddenly stop working. Because the heading angle cannot be measured, the reduced attitude control strategy is designed and the stability of reduced state of the system is proved using perturbation method.

  6. Star sensors for autonomous attitude control and navigation

    Science.gov (United States)

    van Bezooijen, Roelof W. H.

    1992-11-01

    The attitude control and navigation systems of future advanced spacecraft will be characterized by a high degree of autonomy, very high accuracy, efficient commandability, and fast fault recovery. These characteristics are incompatible with the constraints of conventional star sensors which mandate a-priori definition of all onboard attitude fixes and work only if attitude uncertainties remain small. With the availability of accurate, anti-blooming capable CCDs, fast microprocessors, high density memory chips, and star pattern recognition algorithms, it is now feasible to fabricate miniature Autonomous Star Trackers (ASTs) capable of (1) determining their attitude rapidly and reliably while having no a-priori attitude knowledge, (2) autonomous attitude updating, and (3) providing their attitude at rates up to typically 40 Hz. In addition to providing the functionality needed for future missions, ASTs can also be exploited to improve the reliability, mass, power, and cost of spacecraft and reduce the cost of operating them. This paper describes star identification schemes used in the past, it discusses a number of star pattern recognition algorithms, and provides the main characteristics of current CCD star trackers. A number of specific functions enabled or enhanced by an AST are described including fast attitude acquisition, rapid fault recovery, attitude safing, gyroless/cheap-gyro attitude control, autonomous target acquisition by astronomy telescopes, autonomous optical navigation, and precision pointing to terrestrial targets. The AST being developed at Lockheed uses a fast, memory-efficient, and highly robust star pattern recognition algorithm based on matching groups of stars. The algorithm, which is also applicable to star scanners, is described along with a realistic simulation program for testing its performance. It is shown that an AST with an 11.3 degree FOV diameter, a database of 4100 guide stars, a 25 MHz MC68030 class microprocessor, and 800 Kbytes

  7. Sliding Mode Attitude Control for Magnetic Actuated Satellite

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    1998-01-01

    control torques can only be generated perpendicular to the local geomagnetic field vector. This has been a serious obstacle for using magnetorquer based control for three-axis attitude control. This paper deals with three-axis stabilization of a low earth orbit satellite. The problem of controlling......Magnetic torquing is attractive as a control principle on small satellites. The actuation principle is to use the interaction between the earth's magnetic field and magnetic field generated by a coil set in the satellite. This control principle is inherently nonlinear, and difficult to use because...... the spacecraft attitude using only magnetic torquing is realized in the form of the sliding mode control. A three dimensional sliding manifold is proposed, and it is shown that the satellite motion on the sliding manifold is asymptotically stable...

  8. Attitude tracking control of flexible spacecraft with large amplitude slosh

    Science.gov (United States)

    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.

  9. Fuzzy control of attitude of four - rotor UAV

    Science.gov (United States)

    Zhang, Zexiang; Hu, Shengbin

    2017-08-01

    The four - rotor unmanned aerial vehicle (UAV) is the object of study, in this paper. In order to solve the problem of poor robustness and low control precision of the four-rotor unmanned aerial vehicle (UAV) control system, and realized the stability control problem of the four-rotor UAV attitude. First, the dynamic model of the four-rotor unmanned aerial vehicle is established. And on this basis, a fuzzy controller is designed, and used to control the channel. Then, the simulation platform is built by Matlab / Simulink simulation software, and the performance of the designed fuzzy controller is analyzed comprehensively. It is also determined whether the algorithm can control the attitude of the four rotor unmanned aerial vehicle. The simulation results fully verify the accuracy of the model, and proved fuzzy controller has better dynamic performance and robustness under appropriate parameters so that UAVs can fly stable. The algorithm can improve the anti-jamming performance and control accuracy of the system, it has a certain significance for the actual four-rotor aircraft attitude control.

  10. Precision tethered satellite attitude control. Ph.D. Thesis

    Science.gov (United States)

    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).

  11. Attitude control of reentry vehicles in roll channel using single-gimbal control moment gyros and a reaction control system

    National Research Council Canada - National Science Library

    Yu, Xiang; Liu, Kun

    2017-01-01

    A novel roll-channel attitude control scheme using a combination of single-gimbal control moment gyros and a reaction control system is proposed, providing sufficient control torque during the whole reentry process...

  12. Spherical gyroscopic moment stabilizer for attitude control of microsatellites

    Science.gov (United States)

    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.

  13. Position and Attitude Alternate of Path Tracking Heading Control

    Directory of Open Access Journals (Sweden)

    Baocheng Tan

    2014-03-01

    Full Text Available The path tracking control algorithm is one of the key problems in the control system design of autonomous vehicle. In this paper, we have conducted dynamic modeling for autonomous vehicle, the relationship between course deviation and yaw rate and centroid deflection angle. From the angle of the dynamics and geometrical, this paper have described the path tracking problem, analyzed the emergence of the eight autonomous vehicles pose binding - position and attitude alternate control methods to identify the relationship between posture and the controlling variables, and design a controller, the experimental results verify the feasibility and effectiveness of this control method.

  14. Cassini at Saturn Proximal Orbits - Attitude Control Challenges

    Science.gov (United States)

    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.

  15. Robust attitude coordinated control for spacecraft formation with communication delays

    Directory of Open Access Journals (Sweden)

    Jian ZHANG

    2017-06-01

    Full Text Available In this paper, attitude coordinated tracking control algorithms for multiple spacecraft formation are investigated with consideration of parametric uncertainties, external disturbances, communication delays and actuator saturation. Initially, a sliding mode delay-dependent attitude coordinated controller is proposed under bounded external disturbances. However, neither inertia uncertainty nor actuator constraint has been taken into account. Then, a robust saturated delay-dependent attitude coordinated control law is further derived, where uncertainties and external disturbances are handled by Chebyshev neural networks (CNN. In addition, command filter technique is introduced to facilitate the backstepping design procedure, through which actuator saturation problem is solved. Thus the spacecraft in the formation are able to track the reference attitude trajectory even in the presence of time-varying communication delays. Rigorous analysis is presented by using Lyapunov-Krasovskii approach to demonstrate the stability of the closed-loop system under both control algorithms. Finally, the numerical examples are carried out to illustrate the efficiency of the theoretical results.

  16. Knowledge and attitudes of infection prevention and control among ...

    African Journals Online (AJOL)

    Methods: To assess students' knowledge and attitudes regarding infection prevention and control and their sources of information, a self-administered questionnaire was used to look at standard precautions especially hands hygiene. Results: One hundred sixty two students participated in this study of which 31 were ...

  17. Knowledge and attitudes of infection prevention and control among ...

    African Journals Online (AJOL)

    EB

    Methods: To assess students' knowledge and attitudes regarding infection prevention and control and their sources of information, a self-administered questionnaire was used to look at standard precautions especially hands hygiene. Results: One hundred sixty two ... vehicles as food or water. Exposure to infectious.

  18. Satellite Attitude Control Using Only Electromagnetic Actuation

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    of the work was on the class of periodic systems reflecting orbital motion of the satellite. In addition to a theoretical treatment, the thesis contains a large portion of application considerations. The controllers developed were implemented for the Danish Ørsted satellite. The control concept considered......The primary purpose of this work was to develop control laws for three axis stabilization of a magnetic actuated satellite. This was achieved by a combination of linear and nonlinear system theory. In order to reach this goal new theoretical results were produced in both fields. The focus...... was that interaction between the Earth's magnetic field and a magnetic field generated by a set of coils in the satellite can be used for actuation. Magnetic torquing was found attractive for generation of control torques on small satellites, since magnetic control systems are relatively lightweight, require low power...

  19. Design and Stability of an On-Orbit Attitude Control System Using Reaction Control Thrusters

    Science.gov (United States)

    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.

  20. Attitude Optimal Backstepping Controller Based Quaternion for a UAV

    Directory of Open Access Journals (Sweden)

    Kaddouri Djamel

    2016-01-01

    Full Text Available A hierarchical controller design based on nonlinear H∞ theory and backstepping technique is developed for a nonlinear and coupled dynamic attitude system using conventional quaternion based method. The derived controller combines the attractive features of H∞ optimal controller and the advantages of the backstepping technique leading to a control law which avoids winding phenomena. Performance issues of the controller are illustrated in a simulation study made for a four-rotor vertical take-off and landing (VTOL aerial robot prototype known as the quadrotor aircraft.

  1. Attitude Control of a Satellite by using Digital Signal Processing

    Directory of Open Access Journals (Sweden)

    Adirelle C. Santana

    2012-03-01

    Full Text Available This article has discussed the development of a three-axis attitude digital controller for an artificial satellite using a digital signal processor. The main motivation of this study is the attitude control system of the satellite Multi-Mission Platform, developed by the Brazilian National Institute for Space Research for application in different sort of missions. The controller design was based on the theory of the Linear Quadratic Gaussian Regulator, synthesized from the linearized model of the motion of the satellite, i.e., the kinematics and dynamics of attitude. The attitude actuators considered in this study are pairs of cold gas jets powered by a pulse width/pulse frequency modulator. In the first stage of the project development, a system controller for continuous time was studied with the aim of testing the adequacy of the adopted control. The next steps had included an analysis of discretization techniques, the setting time of sampling rate, and the testing of the digital version of the Linear Quadratic Gaussian Regulator controller in the MATLAB/SIMULINK. To fulfill the study, the controller was implemented in a digital signal processor, specifically the Blackfin BF537 from Analog Devices, along with the pulse width/pulse frequency modulator. The validation tests used a scheme of co-simulation, where the model of the satellite was simulated in MATLAB/SIMULINK, while the controller and modulator were processed in the digital signal processor with a tool called Processor-In-the-Loop, which acted as a data communication link between both environments.function and required time to achieve a given mission accuracy are determined, and results are provided as illustration.

  2. Orbit keeping attitude control for space station

    Science.gov (United States)

    Barrows, D.; Bedell, H.

    1983-01-01

    It is pointed out that on-orbit configuration variability is expected to be a characteristic of a space station. The implementation of such a chracteristic will present reboost and thruster control system designers with a number of new challenges. The primary requirement for the space station orbit reboost (or orbit keeping) system is to ensure system viability for extended duration and prevent an uncontrolled reentry as with Skylab. For a station in a low earth orbit, earodynamic drag will be sufficient to cause relatively quick orbit altitude decay. A propulsion system is, therefore, needed to counteract the aerodynamic drag forces and to boost the vehicle to the desired orbit altitudes. A description is given of a typical reboost operational procedure and propellant requirements. Attention is given to thruster control systems, and aspects of reboost guidance.

  3. Spacecraft Attitude Control in Hamiltonian Framework

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2000-01-01

    is the sum of the gradient of the potential energy and the dissipative force. It is shown that this control law makes the system uniformly asymptotically stable to the desired reference point. Three problems were addressed in the paper: spacecraft stabilization in the inertial frame, libration damping...... with the use of electromagnetic coils and a slew maneuver with an additional objective of avoiding undesirable regions e.g. causing blindness of optical sensors...

  4. Autonomous Attitude Determination and Control System for the Ørsted Satellite

    DEFF Research Database (Denmark)

    Bak, Thomas; Wisniewski, Rafal; Blanke, M.

    1996-01-01

    The Ørsted Satellite mission imposes comparatively high requirements on autonomy of the attitude control system.......The Ørsted Satellite mission imposes comparatively high requirements on autonomy of the attitude control system....

  5. Periodic H-2 Synthesis for Spacecraft Attitude Control with Magnetometers

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Stoustrup, Jakob

    2004-01-01

    A control synthesis for a spacecraft equipped with a set of magnetorquer coils is addressed. The electromagnetic actuation is particularly attractive for small low-cost spacecraft missions, due to their relatively low price, high reliability, light weight, and low power consumption. The interaction...... between the Earth´s magnetic field and an artificial magnetic field generated by the coils produces a control torque. The magnetic attitude control is intrinsically periodic due to cyclic variation of the geomagnetic field in orbit. The control performance is specified by the generalized H2 operator norm...

  6. Integrated Power and Attitude Control System (IPACS) technology developments

    Science.gov (United States)

    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.

  7. Colloid Thruster for Attitude Control Systems (ACS) and Tip-off Control Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and test key technologies needed for an integrated, high thrust colloid thruster system with no moving parts, for spacecraft attitude control...

  8. Hispanics' locus of control, acculturation, and wellness attitudes.

    Science.gov (United States)

    Valentine, Sean R; Godkin, Jennie; Doughty, Graeme P

    2008-01-01

    There is reason to believe that various cultural attitudes and beliefs influence certain health behaviors, and additional research should identify the causes of such behaviors. This study explored the relationships among cultural identity, acculturation, locus of control, and health beliefs using a sample of 110 Hispanic individuals taking college classes in the southern or southwestern United States. Path analysis indicated that an external locus of control was positively related to health barrier perceptions and that acculturation was negatively related to health barrier perceptions. The findings suggest that Hispanics' perceived control over health outcomes and positive health beliefs could be enhanced with culturally perceptive counseling.

  9. Attitude and Translation Control of a Solar Sail Vehicle

    Science.gov (United States)

    Singh, Gurkirpal

    2008-01-01

    A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft s center of mass causes solar-pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sunline, requires a low-authority vane/propulsive subsystem. Translation control of the vehicle is achieved by directing the solar-pressure-induced force in the proper inertial direction. This requires attitude control. Attitude and translation degrees-of-freedom are therefore coupled. A guidance law is proposed, which allows the vehicle to stationkeep at an appropriate point on the inertially-rotating Sun-Earth line. Power requirements for moving the bus are minimal. Extensive software simulations have been performed to demonstrate the feasibility of this concept.

  10. Position and attitude tracking control for a quadrotor UAV.

    Science.gov (United States)

    Xiong, Jing-Jing; Zheng, En-Hui

    2014-05-01

    A synthesis control method is proposed to perform the position and attitude tracking control of the dynamical model of a small quadrotor unmanned aerial vehicle (UAV), where the dynamical model is underactuated, highly-coupled and nonlinear. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly, a controller of the fully actuated subsystem is designed through a novel robust terminal sliding mode control (TSMC) algorithm, which is utilized to guarantee all state variables converge to their desired values in short time, the convergence time is so small that the state variables are acted as time invariants in the underactuated subsystem, and, a controller of the underactuated subsystem is designed via sliding mode control (SMC), in addition, the stabilities of the subsystems are demonstrated by Lyapunov theory, respectively. Lastly, in order to demonstrate the robustness of the proposed control method, the aerodynamic forces and moments and air drag taken as external disturbances are taken into account, the obtained simulation results show that the synthesis control method has good performance in terms of position and attitude tracking when faced with external disturbances. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Satellite Attitude Control System Design considering the Fuel Slosh Dynamics

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Gadelha de Souza

    2014-01-01

    Full Text Available The design of the satellite attitude control system (ACS becomes more complex when the satellite structure has different type of components like, flexible solar panels, antennas, mechanical manipulators, and tanks with fuel. A crucial interaction can occur between the fuel slosh motion and the satellite rigid motion during translational and/or rotational manoeuvre since these interactions can change the satellite centre of mass position damaging the ACS pointing accuracy. Although, a well-designed controller can suppress such disturbances quickly, the controller error pointing may be limited by the minimum time necessary to suppress such disturbances thus affecting the satellite attitude acquisition. As a result, the design of the satellite controller needs to explore the limits between the conflicting requirements of performance and robustness. This paper investigates the effects of the interaction between the liquid motion (slosh and the satellite dynamics in order to predict what the damage to the controller performance and robustness is. The fuel slosh dynamics is modelled by a pendulum which parameters are identified using the Kalman filter technique. This information is used to design the satellite controller by the linear quadratic regulator (LQR and linear quadratic Gaussian (LQG methods to perform a planar manoeuvre assuming thrusters are actuators.

  12. Backstepping-Based Inverse Optimal Attitude Control of Quadrotor

    Directory of Open Access Journals (Sweden)

    An Honglei

    2013-05-01

    Full Text Available Abstract Input saturation must be taken into account for applying rapid reorientation in the large angle manoeuvre of a quadrotor. In this paper, a backstepping-based inverse optimal attitude controller (BIOAC is derived which has the property of a maximum convergence rate in the sense of a control Lyapunov function (CLF under input torque limitation. In the controller, a backstepping technique is used for handling the complexity introducing by the unit quaternion representation of the attitude of a quadrotor with four parameters. Moreover, the inverse optimal approach is employed to circumvent the difficulty of solving the Hamilton-Jacobi-Bellman (HJB equation. The performance of BIOAC is compared with a PD controller in which the input torque limitation is not considered under the same unit quaternion representation using numerical simulation while the results show that BIOAC gains faster convergence with less control effort. Next, BIOAC is realized on a test bed and the effectiveness of the control law is verified by experimental studies.

  13. Fuzzy attitude control for a nanosatellite in leo orbit

    Science.gov (United States)

    Calvo, Daniel; Laverón-Simavilla, Ana; Lapuerta, Victoria; Aviles, Taisir

    Fuzzy logic controllers are flexible and simple, suitable for small satellites Attitude Determination and Control Subsystems (ADCS). In this work, a tailored fuzzy controller is designed for a nanosatellite and is compared with a traditional Proportional Integrative Derivative (PID) controller. Both control methodologies are compared within the same specific mission. The orbit height varies along the mission from injection at around 380 km down to a 200 km height orbit, and the mission requires pointing accuracy over the whole time. Due to both the requirements imposed by such a low orbit, and the limitations in the power available for the attitude control, a robust and efficient ADCS is required. For these reasons a fuzzy logic controller is implemented as the brain of the ADCS and its performance and efficiency are compared to a traditional PID. The fuzzy controller is designed in three separated controllers, each one acting on one of the Euler angles of the satellite in an orbital frame. The fuzzy memberships are constructed taking into account the mission requirements, the physical properties of the satellite and the expected performances. Both methodologies, fuzzy and PID, are fine-tuned using an automated procedure to grant maximum efficiency with fixed performances. Finally both methods are probed in different environments to test their characteristics. The simulations show that the fuzzy controller is much more efficient (up to 65% less power required) in single maneuvers, achieving similar, or even better, precision than the PID. The accuracy and efficiency improvement of the fuzzy controller increase with orbit height because the environmental disturbances decrease, approaching the ideal scenario. A brief mission description is depicted as well as the design process of both ADCS controllers. Finally the validation process and the results obtained during the simulations are described. Those results show that the fuzzy logic methodology is valid for small

  14. Observer Based Sliding Mode Attitude Control: Theoretical and Experimental Results

    Directory of Open Access Journals (Sweden)

    U. Jørgensen

    2011-07-01

    Full Text Available In this paper we present the design of a sliding mode controller for attitude control of spacecraft actuated by three orthogonal reaction wheels. The equilibrium of the closed loop system is proved to be asymptotically stable in the sense of Lyapunov. Due to cases where spacecraft do not have angular velocity measurements, an estimator for the generalized velocity is derived and asymptotic stability is proven for the observer. The approach is tested on an experimental platform with a sphere shaped Autonomous Underwater Vehicle SATellite: AUVSAT, developed at the Norwegian University of Science and Technology.

  15. Integrated Power and Attitude Control for a Spacecraft with Flywheels and Control Moment Gyroscopes

    Science.gov (United States)

    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.

  16. STRAP V - Higher accuracy, lower drift attitude control system. [Stellar Tracking Rocket Attitude Positioning

    Science.gov (United States)

    Budney, T. J.; Collinson, T. W.; Stone, R. W.

    1982-01-01

    The STRAP V system was developed to provide higher accuracy and lower limit cycle fine pointing (+ or - 7 arcseconds) in all three axes at targets which cannot be tracked by startrackers or solar trackers. The system provides an increase in pointing performance over that obtainable with the STRAP IV (1) Attitude Control System (ACS). The STRAP IV concept of third axis updates is utilized to reduce pointing errors, using the flight-proven STRAP III (2) system as a first stage. Flight aspect photographs and telemetry records show that the STRAP V objectives have been met. The STRAP IV major error contributors have been significantly reduced and the tracking flexibility has been increased with only minor error contributions. Attention is given to the basic STRAP III control modes, major STRAP IV system error sources, tuned restrained inertial gyros (TRIGs), the programmable sequence timer, the STRAP V control box, third axis update, system gyro alignments, and STRAP V operational capabilities.

  17. Design of Attitude Control System for UAV Based on Feedback Linearization and Adaptive Control

    Directory of Open Access Journals (Sweden)

    Wenya Zhou

    2014-01-01

    Full Text Available Attitude dynamic model of unmanned aerial vehicles (UAVs is multi-input multioutput (MIMO, strong coupling, and nonlinear. Model uncertainties and external gust disturbances should be considered during designing the attitude control system for UAVs. In this paper, feedback linearization and model reference adaptive control (MRAC are integrated to design the attitude control system for a fixed wing UAV. First of all, the complicated attitude dynamic model is decoupled into three single-input single-output (SISO channels by input-output feedback linearization. Secondly, the reference models are determined, respectively, according to the performance indexes of each channel. Subsequently, the adaptive control law is obtained using MRAC theory. In order to demonstrate the performance of attitude control system, the adaptive control law and the proportional-integral-derivative (PID control law are, respectively, used in the coupling nonlinear simulation model. Simulation results indicate that the system performance indexes including maximum overshoot, settling time (2% error range, and rise time obtained by MRAC are better than those by PID. Moreover, MRAC system has stronger robustness with respect to the model uncertainties and gust disturbance.

  18. High Accuracy Attitude Control System Design for Satellite with Flexible Appendages

    OpenAIRE

    Wenya Zhou; Haixu Wang; Zhengwei Ruan; Zhigang Wu; Enmei Wang

    2014-01-01

    In order to realize the high accuracy attitude control of satellite with flexible appendages, attitude control system consisting of the controller and structural filter was designed. When the low order vibration frequency of flexible appendages is approximating the bandwidth of attitude control system, the vibration signal will enter the control system through measurement device to bring impact on the accuracy or even the stability. In order to reduce the impact of vibration of appendages on ...

  19. Cosmic Background Explorer (COBE) transfer orbit attitude control system

    Science.gov (United States)

    Placanica, Samuel J.; Flatley, Thomas W.

    1986-01-01

    The Cosmic Background Explorer (COBE) spacecraft will be launched by the Shuttle from Vandenberg AFB into a 300 km altitude, 99 deg inclination, 6 a.m. or 6 p.m. ascending node orbit. After release from the Remote Manipulator System (RMS) arm, an on-board monopropellant hydrazine propulsion system will raise the orbit altitude to 900 km. The spacecraft continuously spins during transfer orbit operations with the spin axis nominally horizontal and in or near the orbit plane. The blowdown propulsion system consists of twelve 5 lb thrusters (3 'spin', 3 'despin', and 6 'axial') with the latter providing initially 30 lb of force parallel to the spin axis for orbit raising. The spin/despin jets provide a constant roll rate during the transfer orbit phase of the mission and the axials control pitch and yaw. The axial thrusters are pulsed on for attitude control during coast periods and are normally on- and off-modulated for control during orbit raising. Attitude sensors employed in the control loops include an array of two-axis digital sun sensors and three planar earth scanners for position measurements, as well as six gyroscopes for rate information. System redundancy is achieved by means of unique three-axes-in-a-plane geometry. This triaxial concept results in a fail-safe operational system with no performance degradation for many different component failure modes.

  20. Fuzzy attitude control of solar sail via linear matrix inequalities

    Science.gov (United States)

    Baculi, Joshua; Ayoubi, Mohammad A.

    2017-09-01

    This study presents a fuzzy tracking controller based on the Takagi-Sugeno (T-S) fuzzy model of the solar sail. First, the T-S fuzzy model is constructed by linearizing the existing nonlinear equations of motion of the solar sail. Then, the T-S fuzzy model is used to derive the state feedback controller gains for the Twin Parallel Distributed Compensation (TPDC) technique. The TPDC tracks and stabilizes the attitude of the solar sail to any desired state in the presence of parameter uncertainties and external disturbances while satisfying actuator constraints. The performance of the TPDC is compared to a PID controller that is tuned using the Ziegler-Nichols method. Numerical simulation shows the TPDC outperforms the PID controller when stabilizing the solar sail to a desired state.

  1. STRAP IV - High accuracy, low drift attitude control system.

    Science.gov (United States)

    Shrewsberry, D. J.; Budney, T. J.; Riley, D. C.; Schuler, B. C.

    1973-01-01

    The STRAP IV attitude control system was designed, tested, and successfully launched to provide stable high accuracy pointing at nontrackable X-ray sources. On its initial flight (May 19, 1972), the STRAP IV control system updated its high accuracy, rate integrating gyros on two successive stellar targets and then maneuvered the rocket body to point the experimental payload at two separate X-ray sources and an X-ray-free background location. The third axis, which remained under the control of a coarse free gyro, was updated by a technique of successive star-target coordinate transformation to ensure the correct fine-axis azimuth alignment for the high accuracy inertial maneuvers. Pointing accuracies of 4 arc min with limit cycle stability of less than 20 arc sec peak to peak were obtained on all targets.

  2. Space station dynamics, attitude control and momentum management

    Science.gov (United States)

    Sunkel, John W.; Singh, Ramen P.; Vengopal, Ravi

    1989-01-01

    The Space Station Attitude Control System software test-bed provides a rigorous environment for the design, development and functional verification of GN and C algorithms and software. The approach taken for the simulation of the vehicle dynamics and environmental models using a computationally efficient algorithm is discussed. The simulation includes capabilities for docking/berthing dynamics, prescribed motion dynamics associated with the Mobile Remote Manipulator System (MRMS) and microgravity disturbances. The vehicle dynamics module interfaces with the test-bed through the central Communicator facility which is in turn driven by the Station Control Simulator (SCS) Executive. The Communicator addresses issues such as the interface between the discrete flight software and the continuous vehicle dynamics, and multi-programming aspects such as the complex flow of control in real-time programs. Combined with the flight software and redundancy management modules, the facility provides a flexible, user-oriented simulation platform.

  3. Controlled comparison of attitudes of psychiatrists, general practitioners, homosexual doctors and homosexual men to male homosexuality.

    Science.gov (United States)

    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

  4. Pushing the Limits of Cubesat Attitude Control: A Ground Demonstration

    Science.gov (United States)

    Sanders, Devon S.; Heater, Daniel L.; Peeples, Steven R.; Sules. James K.; Huang, Po-Hao Adam

    2013-01-01

    A cubesat attitude control system (ACS) was designed at the NASA Marshall Space Flight Center (MSFC) to provide sub-degree pointing capabilities using low cost, COTS attitude sensors, COTS miniature reaction wheels, and a developmental micro-propulsion system. The ACS sensors and actuators were integrated onto a 3D-printed plastic 3U cubesat breadboard (10 cm x 10 cm x 30 cm) with a custom designed instrument board and typical cubesat COTS hardware for the electrical, power, and data handling and processing systems. In addition to the cubesat development, a low-cost air bearing was designed and 3D printed in order to float the cubesat in the test environment. Systems integration and verification were performed at the MSFC Small Projects Rapid Integration & Test Environment laboratory. Using a combination of both the miniature reaction wheels and the micro-propulsion system, the open and closed loop control capabilities of the ACS were tested in the Flight Robotics Laboratory. The testing demonstrated the desired sub-degree pointing capability of the ACS and also revealed the challenges of creating a relevant environment for development testin

  5. Health literacy and parent attitudes about weight control for children.

    Science.gov (United States)

    Liechty, Janet M; Saltzman, Jaclyn A; Musaad, Salma M

    2015-08-01

    The purpose of this study was to examine associations between parental health literacy and parent attitudes about weight control strategies for young children. Parental low health literacy has been associated with poor child health outcomes, yet little is known about its relationship to child weight control and weight-related health information-seeking preferences. Data were drawn from the STRONG Kids Study, a Midwest panel survey among parents of preschool aged children (n = 497). Parents endorsed an average of 4.3 (SD =2.8) weight loss strategies, 53% endorsed all three recommended weight loss strategies for children, and fewer than 1% of parents endorsed any unsafe strategies. Parents were most likely to seek child weight loss information from healthcare professionals but those with low (vs. adequate) health literacy were significantly less likely to use the Internet or books and more likely to use minister/clergy as sources. Poisson and logistic regressions showed that higher health literacy was associated with endorsement of more strategies overall, more recommended strategies, and greater odds of endorsing each specific recommended strategy for child weight control, after adjusting for parent age, education, race/ethnicity, income, marital status, weight concern, and child BMI percentile. Findings suggest that health literacy impacts parental views about child weight loss strategies and health information-seeking preferences. Pediatric weight loss advice to parents should include assessment of parent attitudes and prior knowledge about child weight control and facilitate parent access to reliable sources of evidence-informed child weight control information. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. ATS-6 engineering performance report. Volume 2: Orbit and attitude controls

    Science.gov (United States)

    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.

  7. The Impact of Personal Attitude, Subjective Norm, and Perceived Behavioural Control on Entrepreneurial Intentions of Women

    National Research Council Canada - National Science Library

    DINC, M. Sait; BUDIC, Semira

    2016-01-01

    .... The purpose of the study is to examine the relationship between demographic variables, personal attitude, subjective norm, perceived behavioural control, and entrepreneurial intentions of women...

  8. Motor Control of Two Flywheels Enabling Combined Attitude Control and Bus Regulation

    Science.gov (United States)

    Kenny, Barbara H.

    2004-01-01

    This presentation discussed the flywheel technology development work that is ongoing at NASA GRC with a particular emphasis on the flywheel system control. The "field orientation" motor/generator control algorithm was discussed and explained. The position-sensorless angle and speed estimation algorithm was presented. The motor current response to a step change in command at low (10 kRPM) and high (60 kRPM) was discussed. The flywheel DC bus regulation control was explained and experimental results presented. Finally, the combined attitude control and energy storage algorithm that controls two flywheels simultaneously was presented. Experimental results were shown that verified the operational capability of the algorithm. shows high speed flywheel energy storage (60,000 RPM) and the successful implementation of an algorithm to simultaneously control both energy storage and a single axis of attitude with two flywheels. Overall, the presentation demonstrated that GRC has an operational facility that

  9. Design of a Control Moment Gyroscope Attitude Actuation System for the Attitude Control Subsystem Proving Ground

    Science.gov (United States)

    2013-03-01

    control using a CMG array is prone to geometric singularities. Singularities are commonly avoided by limiting a vehicle’s performance via limitation of the...ball bearings, tolerancing and fitting, materials, or balancing. For help in these areas, where I had only general knowledge, we looked to experts

  10. Preliminary Test of Adaptive Neuro-Fuzzy Inference System Controller for Spacecraft Attitude Control

    Directory of Open Access Journals (Sweden)

    Sung-Woo Kim

    2012-12-01

    Full Text Available The problem of spacecraft attitude control is solved using an adaptive neuro-fuzzy inference system (ANFIS. An ANFIS produces a control signal for one of the three axes of a spacecraft’s body frame, so in total three ANFISs are constructed for 3-axis attitude control. The fuzzy inference system of the ANFIS is initialized using a subtractive clustering method. The ANFIS is trained by a hybrid learning algorithm using the data obtained from attitude control simulations using state-dependent Riccati equation controller. The training data set for each axis is composed of state errors for 3 axes (roll, pitch, and yaw and a control signal for one of the 3 axes. The stability region of the ANFIS controller is estimated numerically based on Lyapunov stability theory using a numerical method to calculate Jacobian matrix. To measure the performance of the ANFIS controller, root mean square error and correlation factor are used as performance indicators. The performance is tested on two ANFIS controllers trained in different conditions. The test results show that the performance indicators are proper in the sense that the ANFIS controller with the larger stability region provides better performance according to the performance indicators.

  11. GPS IIF yaw attitude control during eclipse season

    Science.gov (United States)

    Dilssner, F.; Springer, T.; Enderle, W.

    2011-12-01

    On May 27, 2010, the first satellite of the Block II "follow-on" (Block IIF) series, the fourth generation of Global Positioning System (GPS) spacecraft, has been successfully placed into orbit. GPS IIF-1, also referred to as space vehicle number (SVN) 62, has been injected into orbital plane B, slot position 2 of the GPS constellation. After completing three months of comprehensive in-orbit testing, the satellite entered service for the US Air Force (USAF) on August 26, 2010. A little over a year after the inaugural launch of GPS IIF-1, the USAF has now launched the second spacecraft of the IIF series (SVN-63). The IIF series includes a total of 12 satellites: SVN-62 through SVN-73. Despite having many technical advances over their predecessors such as enhanced rubidium frequency standards, more precise and powerful signals and an extended design life, the three-axis stabilized Block IIF satellites follow a completely different yaw attitude scheme, when passing through the Earth's shadow, to the Block IIA and IIR spacecraft. We will describe how high-rate carrier phase and pseudo-range measurements from a global GPS tracking network can be exploited to precisely monitor the yaw attitude behavior of SVN-62 and SVN-63 during their solar eclipse phases. The insights gained from this study have led to the development of a new GPS Block IIF yaw attitude model. We will show that the yaw rate of a Block IIF space vehicle is kept constant to the value needed to get the satellite back to near its nominal attitude when leaving the Earth's shadow and that a IIF satellite being in deep eclipse therefore needs to yaw significantly faster than an eclipsing IIF space vehicle passing only partly through the Earth's shadow. How the satellites' attitude control system (ACS) exactly computes this dynamical yaw rate parameter will be discussed here as well. Moreover, we will report on yaw attitude anomalies occurring when the GPS Block IIF satellites are shaded from the Sun by the

  12. Enceladus plume density from Cassini spacecraft attitude control data

    Science.gov (United States)

    Lorenz, Ralph D.; Burk, Thomas A.

    2018-01-01

    The plumes of Enceladus are of interest both as a geophysical phenomenon, and as an astrobiological opportunity for sampling internal material. Here we report measurements of the total mass density (gas plus dust, a combination not reported before except in the engineering literature) deduced from telemetry of Cassini's Attitude and Articulation Control System (AACS), as the spacecraft's thrusters or reaction wheels worked to maintain the desired attitude in the presence of drag torques during close flybys. The drag torque shows good agreement with the water vapor density measured by other instruments during the E5 encounter, but indicates a rather higher mass density on other passes (E3, E14), possibly indicating variations in gas composition and/or gas:dust ratio. The spacecraft appears to have intercepted about 0.2 g of material, on flyby E21 in October 2015 indicating a peak mass density of ∼5.5 × 10-11 kg m-3, the highest of all the flybys measured (E3, E5, E7, E9, E14, E21).

  13. Chinese attitudes, norms, behavioral control and gambling involvement in Macao.

    Science.gov (United States)

    Wu, Anise M S; Lai, Mark H C; Tong, Kowk Kit; Tao, Vivienne Y K

    2013-12-01

    This study tested the applicability of the theory of planned behavior (TPB) on gambling intention and involvement in a representative Chinese sample in Macao, recruited by a random residential number dialing method. We successfully interviewed 685 respondents, with about one-third of them reporting that they had participated in gambling activities during the 12 months prior to the interview. The results of structural equation modeling suggested that favorable attitudes toward superstition and techniques, poor sense of perceived behavioral control over gambling refusal, and high gambling intention increased vulnerability to excessive gambling involvement. These findings generally support the efficacy of the TPB in explaining gambling intention and involvement among both Chinese gamblers and non-gamblers. Some practical implications of the findings are discussed within the Chinese context.

  14. Attitude Analysis and Robust Adaptive Backstepping Sliding Mode Control of Spacecrafts Orbiting Irregular Asteroids

    Directory of Open Access Journals (Sweden)

    Chunhui Liang

    2014-01-01

    Full Text Available Attitude stability analysis and robust control algorithms for spacecrafts orbiting irregular asteroids are investigated in the presence of model uncertainties and external disturbances. Rigid spacecraft nonlinear attitude models are considered and detailed attitude stability analysis of spacecraft subjected to the gravity gradient torque in an irregular central gravity field is included in retrograde orbits and direct orbits using linearized system model. The robust adaptive backstepping sliding mode control laws are designed to make the attitude of the spacecrafts stabilized and responded accurately to the expectation in the presence of disturbances and parametric uncertainties. Numerical simulations are included to illustrate the spacecraft performance obtained using the proposed control laws.

  15. Disturbance observer-based fuzzy control for flexible spacecraft combined attitude & sun tracking system

    Science.gov (United States)

    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.

  16. Attitude Dynamics, Stability, and Control of a Heliogyro Solar Sail

    Science.gov (United States)

    Pimienta-Penalver, Adonis Reinier

    A heliogyro solar sail concept, dubbed `HELIOS', is proposed as an alternative to deep space missions without the need for on-board propellant. Although this type of solar sail has existed in concept for several decades, and some previous studies have investigated certain aspects of its operation, a significant amount of research is still needed to analyze the dynamic and control characteristics of the structure under the projected range of orbital conditions. This work presents an improvement upon the existing discrete-mass models of the heliogyro blade, and the extension of its application from a single membrane blade to a fully-coupled approximation of the dynamics of the HELIOS system with multiple spinning membrane blades around a central hub. The incorporation of structural stiffness and external forcing effects into the model is demonstrated to add a further degree of fidelity in simulating the stability properties of the system. Additionally, the approximated dynamics of multiple-blade heliogyro structures are examined under the effect of solar radiation pressure. Lastly, this study evaluates a control algorithm at each blade root to impose structural integrity and attitude control by coordinating well-known helicopter blade pitching profiles.

  17. Orion Launch Abort Vehicle Attitude Control Motor Testing

    Science.gov (United States)

    Murphy, Kelly J.; Brauckmann, Gregory J.; Paschal, Keith B.; Chan, David T.; Walker, Eric L.; Foley, Robert; Mayfield, David; Cross, Jared

    2011-01-01

    Current Orion Launch Abort Vehicle (LAV) configurations use an eight-jet, solid-fueled Attitude Control Motor (ACM) to provide required vehicle control for all proposed abort trajectories. Due to the forward position of the ACM on the LAV, it is necessary to assess the effects of jet-interactions (JI) between the various ACM nozzle plumes and the external flow along the outside surfaces of the vehicle. These JI-induced changes in flight control characteristics must be accounted for in developing ACM operations and LAV flight characteristics. A test program to generate jet interaction aerodynamic increment data for multiple LAV configurations was conducted in the NASA Ames and NASA Langley Unitary Plan Wind Tunnels from August 2007 through December 2009. Using cold air as the simulant gas, powered subscale models were used to generate interaction data at subsonic, transonic, and supersonic test conditions. This paper presents an overview of the complete ACM JI experimental test program for Orion LAV configurations, highlighting ACM system modeling, nozzle scaling assumptions, experimental test techniques, and data reduction methodologies. Lessons learned are discussed, and sample jet interaction data are shown. These data, in conjunction with computational predictions, were used to create the ACM JI increments for all relevant flight databases.

  18. Periodic H2 Synthesis for Spacecraft Attitude Determination and Control with a Vector Magnetometer and Magnetorquers

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Stoustrup, Jakob

    2001-01-01

    the expected magnetic field vector and the true magnetometer data is used for the attitude determination. The magnetic attitude control and determination is intrinsically periodic due to periodic nature of the geomagnetic field variation in orbit. The control performance is specified by the generalized H2...

  19. Attitude control system of the Delfi-n3Xt satellite

    NARCIS (Netherlands)

    Reijneveld, J.; Choukroun, D.

    2013-01-01

    This work is concerned with the development of the attitude control algorithms that will be implemented on board of the Delfi-n3xt nanosatellite, which is to be launched in 2013. One of the mission objectives is to demonstrate Sun pointing and three axis stabilization. The attitude control modes and

  20. Adaptive fuzzy logic controller with direct action type structures for InnoSAT attitude control system

    Science.gov (United States)

    Bakri, F. A.; Mashor, M. Y.; Sharun, S. M.; Bibi Sarpinah, S. N.; Abu Bakar, Z.

    2016-10-01

    This study proposes an adaptive fuzzy controller for attitude control system (ACS) of Innovative Satellite (InnoSAT) based on direct action type structure. In order to study new methods used in satellite attitude control, this paper presents three structures of controllers: Fuzzy PI, Fuzzy PD and conventional Fuzzy PID. The objective of this work is to compare the time response and tracking performance among the three different structures of controllers. The parameters of controller were tuned on-line by adjustment mechanism, which was an approach similar to a PID error that could minimize errors between actual and model reference output. This paper also presents a Model References Adaptive Control (MRAC) as a control scheme to control time varying systems where the performance specifications were given in terms of the reference model. All the controllers were tested using InnoSAT system under some operating conditions such as disturbance, varying gain, measurement noise and time delay. In conclusion, among all considered DA-type structures, AFPID controller was observed as the best structure since it outperformed other controllers in most conditions.

  1. Optimal Attitude Control of Agile Spacecraft Using Combined Reaction Wheel and Control Moment Gyroscope Arrays

    Science.gov (United States)

    2015-12-01

    for attitude control of a satellite in space begin with Euler’s equation ~Mb̂ = Ib̂ ~̇ω b̂î b̂ + ~ωb̂î b̂ × Ib̂~ωb̂îb̂ (2.1) where ~Mb̂ is a vector...calculation is given in Section 2.5. The final set of equations needed to study satellite attitude control is a set of kinematic relations...greater than 0.025% over the whole mission. Due to the nonlinear equations involved in satellite control, the ~̇hmax value is further checked and

  2. Design of an Adaptive-Neural Network Attitude Controller of a Satellite using Reaction Wheels

    Directory of Open Access Journals (Sweden)

    Abbas Ajorkar

    2015-04-01

    Full Text Available In this paper, an adaptive attitude control algorithm is developed based on neural network for a satellite using four reaction wheels in a tetrahedron configuration. Then, an attitude control based on feedback linearization control has been designed and uncertainties in the moment of inertia matrix and disturbances torque have been considered. In order to eliminate the effect of these uncertainties, a multilayer neural network with back-propagation law is designed. In this structure, the parameters of the moment of inertia matrix and external disturbances are estimated and used in feedback linearization control law. Finally, the performance of the designed attitude controller is investigated by several simulations.

  3. [Development of knowledge, attitude and practice questionnaire on prevention and control of occupational diseases].

    Science.gov (United States)

    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.

  4. Single Axis Attitude Control and DC Bus Regulation with Two Flywheels

    Science.gov (United States)

    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.

  5. Integrated Orbit and Attitude Control for a Nanosatellite with Power Constraints

    Science.gov (United States)

    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.

  6. Attitude Stabilization Control of a Quadrotor UAV by Using Backstepping Approach

    Directory of Open Access Journals (Sweden)

    Xing Huo

    2014-01-01

    Full Text Available The modeling and attitude stabilization control problems of a four-rotor vertical takeoff and landing unmanned air vehicle (UAV known as the quadrotor are investigated. The quadrotor’s attitude is represented by the unit quaternion rather than Euler angles to avoid singularity problem. Taking dynamical behavior of motors into consideration and ignoring aerodynamic effect, a nonlinear controller is developed to stabilize the attitude. The control design is accomplished by using backstepping control technique. The proposed control law is based on the compensation for the Coriolis and gyroscope torques. Applying Lyapunov stability analysis proves that the closed-loop attitude system is asymptotic stable. Moreover, the controller can guarantee that all the states of the system are uniformly ultimately bounded in the presence of external disturbance torque. The effectiveness of the proposed control approach is analytically authenticated and also validated via simulation study.

  7. Nonlinear Attitude Control of Planar Structures in Space Using Only Internal Controls

    Science.gov (United States)

    Reyhanoglu, Mahmut; Mcclamroch, N. Harris

    1993-01-01

    An attitude control strategy for maneuvers of an interconnection of planar bodies in space is developed. It is assumed that there are no exogeneous torques and that torques generated by joint motors are used as means of control so that the total angular momentum of the multibody system is a constant, assumed to be zero. The control strategy utilizes the nonintegrability of the expression for the angular momentum. Large angle maneuvers can be designed to achieve an arbitrary reorientation of the multibody system with respect to an inertial frame. The theoretical background for carrying out the required maneuvers is summarized.

  8. Attitude dynamics and control of a spacecraft using shifting mass distribution

    Science.gov (United States)

    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

  9. Review of reaction spheres for spacecraft attitude control

    Science.gov (United States)

    Zhu, Linyu; Guo, Jian; Gill, Eberhard

    2017-05-01

    With respect to spacecraft attitude control, reaction spheres are promising alternatives to conventional momentum exchange devices for the benefits brought by their 4π rotation. Many design concepts of reaction spheres have been proposed in the past decades, however, developments of the driving unit and the bearing, as well as their combination remain great challenges. To facilitate research and push developments in this field, this paper provides a comprehensive review of reaction spheres. To some extent, an in-depth survey of multi-DOF (degree of freedom) spherical motors and possible bearings is provided, along with their advantages and weaknesses addressed. Some multi-DOF actuators for different applications, such as robotic joints, are investigated since they share many similar challenges and techniques with reaction spheres. The experimental performances of realized reaction spheres are listed and compared. Limits of current designs are identified and their causes are analyzed and discussed. Compared with existing summaries on multi-DOF actuators and some surveys done for specific reaction spheres' design, this paper provides the first thorough review on reaction spheres, considering approaches to excite and support the free 4π rotation.

  10. Maternal and Paternal Psychological Control as Moderators of the Link between Peer Attitudes and Adolescents' Risky Sexual Behavior

    Science.gov (United States)

    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…

  11. High Accuracy Attitude Control System Design for Satellite with Flexible Appendages

    Directory of Open Access Journals (Sweden)

    Wenya Zhou

    2014-01-01

    Full Text Available In order to realize the high accuracy attitude control of satellite with flexible appendages, attitude control system consisting of the controller and structural filter was designed. When the low order vibration frequency of flexible appendages is approximating the bandwidth of attitude control system, the vibration signal will enter the control system through measurement device to bring impact on the accuracy or even the stability. In order to reduce the impact of vibration of appendages on the attitude control system, the structural filter is designed in terms of rejecting the vibration of flexible appendages. Considering the potential problem of in-orbit frequency variation of the flexible appendages, the design method for the adaptive notch filter is proposed based on the in-orbit identification technology. Finally, the simulation results are given to demonstrate the feasibility and effectiveness of the proposed design techniques.

  12. Design of Attitude Control Systems for CubeSat-Class Nanosatellite

    Directory of Open Access Journals (Sweden)

    Junquan Li

    2013-01-01

    Full Text Available We present a satellite attitude control system design using low-cost hardware and software for a 1U CubeSat. The attitude control system architecture is a crucial subsystem for any satellite mission since precise pointing is often required to meet mission objectives. The accuracy and precision requirements are even more challenging for small satellites where limited volume, mass, and power are available for the attitude control system hardware. In this proposed embedded attitude control system design for a 1U CubeSat, pointing is obtained through a two-stage approach involving coarse and fine control modes. Fine control is achieved through the use of three reaction wheels or three magnetorquers and one reaction wheel along the pitch axis. Significant design work has been conducted to realize the proposed architecture. In this paper, we present an overview of the embedded attitude control system design; the verification results from numerical simulation studies to demonstrate the performance of a CubeSat-class nanosatellite; and a series of air-bearing verification tests on nanosatellite attitude control system hardware that compares the performance of the proposed nonlinear controller with a proportional-integral-derivative controller.

  13. Chattering-Free Adaptive Sliding Mode Control for Attitude Tracking of Spacecraft with External Disturbance

    Directory of Open Access Journals (Sweden)

    Xuxi Zhang

    2014-01-01

    Full Text Available The attitude tracking problem of spacecraft in the presence of unknown disturbance is investigated. By using the adaptive control technique and the Lyapunov stability theory, a chattering-free adaptive sliding mode control law is proposed for the attitude tracking problem of spacecraft with unknown disturbance. Simulation results are employed to demonstrate the effectiveness of the proposed control design technique in this paper.

  14. Reaction Wheel Installation Deviation Compensation for Overactuated Spacecraft with Finite-Time Attitude Control

    Directory of Open Access Journals (Sweden)

    Aihua Zhang

    2013-01-01

    Full Text Available A novel attitude tracking control scheme is presented for overactuated spacecraft to address the attitude stabilization problem in presence of reaction wheel installation deviation, external disturbance and uncertain mass of moment inertia. An adaptive sliding mode control technique is proposed to track the uncertainty. A Lyapunov-based analysis shows that the compensation control law can guarantee that the desired attitude trajectories are followed in finite-time. The key feature of the proposed control strategy is that it globally asymptotically stabilizes the system, even in the presence of reaction wheel installation deviation, external disturbances, and uncertain mass of moment inertia. The attitude track performance using the proposed finite-time compensation control is evaluated through a numerical example.

  15. Semi-active Attitude Control and Off-line Attitude Determination for the SSETI-Express Student Micro-satellite

    DEFF Research Database (Denmark)

    Alminde, Lars

    2005-01-01

    This paper concerns the development of the Attitude Determination and Control System (ADCS) for the SSETI-Express micro-satellite mission. The mission is an educational project involving 14 universities and the European Space Agency (ESA). The satellite has been designed and built, by students......, over a period of only 18 months. This paper emphasises on the trade-offs required to build an operational ADCS system within such a rapidly developing project....

  16. Semi-active Attitude Control and Off-line Attitude Determination for the SEETI-Express Student Micro-satellite

    DEFF Research Database (Denmark)

    Alminde, Lars

    This paper concerns the development of the Attitude Determination and Control System (ADCS) for the SSETI-Express micro-satellite mission. The mission is an educational project involving 14 universities and the European Space Agency (ESA). The satellite has been designed and built, by students......, over a period of only 18 months. This paper emphasises on the trade-offs required to build an operational ADCS system within such a rapidly developing project....

  17. Quaternion-based adaptive output feedback attitude control of spacecraft using Chebyshev neural networks.

    Science.gov (United States)

    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.

  18. Three-Axis Attitude Control of Solar Sails Utilising Reflectivity Control Devices

    Science.gov (United States)

    Theodorou, Theodoros

    Solar sails are spacecraft that utilise the Solar Radiation Pressure, the force generated by impinging photons, to propel themselves. Conventional actuators are not suitable for controlling the attitude of solar sails therefore specific attitude control methods have been devised to tackle this. One of these methods is to change the centre of pressure with respect to the center of mass thus creating a torque. Reflectivity Control Devices (RCDs) have been proposed and successfully used to change the centre of pressure. Current methods that utilise RCDs have control authority over two axis only with no ability to control the torque about the normal of the sail surface. This thesis extends the state of the art and demonstrates 3-axis control by generating arbitrary torque vectors within a convex polyhedron. Two different RCD materials are considered, transmission and diffusion technologies both compatible with the proposed concept. A number of metrics have been developed which facilitate the comparison of different sail configurations. One of these metics is the sun map which is a graphic representation of the sun angles for which control authority is maintained. An iterative design process is presented which makes use of the metrics developed and aids in the design of a sail which meets the mission requirements and constraints. Moreover, the effects of different parameters on the performance of the proposed control concept are discussed. For example it is shown that by alternating the angle between the edge and middle RCDs the control authority increases. The concept's scalability has been investigated and a hybrid control scheme has been devised which makes use of both RCDs and reaction wheels. The RCDs are complemented by the reaction wheels to achieve higher slew rates while in turn the RCDs desaturate the reaction wheels. Finally, a number of simulations are conducted to verify the validity of the proposed concept.

  19. Finite-Time Control for Attitude Tracking Maneuver of Rigid Satellite

    Directory of Open Access Journals (Sweden)

    Mingyi Huo

    2014-01-01

    Full Text Available The problem of finite-time control for attitude tracking maneuver of a rigid spacecraft is investigated. External disturbance, unknown inertia parameters are addressed. As stepping stone, a sliding mode controller is designed. It requires the upper bound of the lumped uncertainty including disturbance and inertia matrix. However, this upper bound may not be easily obtained. Therefore, an adaptive sliding mode control law is then proposed to release that drawback. Adaptive technique is applied to estimate that bound. It is proved that the closed-loop attitude tracking system is finite-time stable. The tracking errors of the attitude and the angular velocity are asymptotically stabilized. Moreover, the upper bound on the lumped uncertainty can be exactly estimated in finite time. The attitude tracking performance with application of the control scheme is evaluated through a numerical example.

  20. The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

    National Research Council Canada - National Science Library

    Mingying Huo; He Liao; Yanfang Liu; Naiming Qi

    2017-01-01

    .... The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit...

  1. Interior and exterior ballistics coupled optimization with constraints of attitude control and mechanical-thermal conditions

    Science.gov (United States)

    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.

  2. Impact of self-esteem, locus of control and gender on attitude ...

    African Journals Online (AJOL)

    esteem scale developed by Adanijo and Oyefeso (1986), locus of control scale developed by Craig, Franklin and Andrew (1981) and attitude towards child adoption and adoptive parent questionnaire designed by the researchers. All measures used ...

  3. Plug-and-Play Compatibility for CubeSat Attitude Determination and Control Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of Plug-and-play Compatibility for CubeSat Attitude Determination and Control Systems (ADACS) is proposed. Existing Maryland Aerospace (MAI) ADACS...

  4. Model predictive control of attitude maneuver of a geostationary flexible satellite based on genetic algorithm

    Science.gov (United States)

    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.

  5. Advanced numerical study of the three-axis magnetic attitude control and determination with uncertainties

    Science.gov (United States)

    Ivanov, D. S.; Ovchinnikov, M. Yu.; Penkov, V. I.; Roldugin, D. S.; Doronin, D. M.; Ovchinnikov, A. V.

    2017-03-01

    Attitude motion of a satellite equipped with magnetic control system is considered. System comprises of three magnetorquers and one three-axis magnetometer. Satellite is stabilized in orbital reference frame using PD controller and extended Kalman filter. Three-axis attitude is analyzed numerically with advanced assumptions: inertia tensor uncertainty, disturbances of unknown nature, magnetometer errors are taken into account. Stabilization and determination accuracy dependence on orbit inclination is studied.

  6. Ground-Based Backup Attitude Control System for the Koreasat Spacecraft

    Science.gov (United States)

    Lee, Byoung-Sun; Kim, Jae-Hoon; Eun, Jong-Won; Kim, Jae-Moung

    1996-12-01

    A ground-based backup attitude control software for the KOREASAT spacecraft was developed. The software is called the Ground Loop Control (GLC). GLC is activated by satellite operator when both Attitude Processor Electronics (APE) of the spacecraft are failed. GLC extracts pitch and roll angles from the normal spacecraft telemetry, and then generates momentum wheel and magnetic torquer commands simultaneously. This paper presents the design of the GLC software and the test of the GLC linked with KOREASAT Dynamic Satellite Simulator (DSS).

  7. Attitude-Tracking Control with Path Planning for Agile Satellite Using Double-Gimbal Control Moment Gyros

    Directory of Open Access Journals (Sweden)

    Peiling Cui

    2012-01-01

    Full Text Available In view of the issue of rapid attitude maneuver control of agile satellite, this paper presents an attitude-tracking control algorithm with path planning based on the improved genetic algorithm, adaptive backstepping control as well as sliding mode control. The satellite applies double gimbal control moment gyro as actuator and is subjected to the external disturbance and uncertain inertia properties. Firstly, considering the comprehensive mathematical model of the agile satellite and the double gimbal control moment gyro, an improved genetic algorithm is proposed to solve the attitude path-planning problem. The goal is to find an energy optimal path which satisfies certain maneuverability under the constraints of the input saturation, actuator saturation, slew rate limit and singularity measurement limit. Then, the adaptive backstepping control and sliding mode control are adopted in the design of the attitude-tracking controller to track accurately the desired path comprised of the satellite attitude quaternion and velocity. Finally, simulation results indicate the robustness and good tracking performance of the derived controller as well as its ability to avert the singularity of double gimbal control moment gyro.

  8. Teacher Attitude to Inspectors and Inspection: Quality Control ...

    African Journals Online (AJOL)

    The study assessed the attitude of teachers in Lagos State to inspectors and inspection. The study took the form of a survey. Two hundred and fifty teachers from public secondary schools were selected as samples for the study using stratified random sampling technique. The instruments used for the data collection was the ...

  9. Combines Attitude Control and Energy Storage for Small Satellites using Variable Speed Control Moment Gyroscopes

    Science.gov (United States)

    2008-06-24

    the EC-45 are listed in Table 7.4(a) while an image of this motor is shown in Figure 7.1(a). The shear contrast in size of the EC-16 and EC-45...Spacecraft Attitude and Orbit Control Systems, 1997, pp. 221–228. [6] Hebner, R., B. J. and Walls , A., “Flywheel Batteries Come Around Again,” IEEE...Achieve- ments,” Powerpoint Presentation. [136] Lappas, V., Ooisthuizen, P., Madle, P., Cowie, L., Yuksel, G., and Fertin, D., “De- sign, Analysis

  10. Inertial attitude control of Voyager spacecraft using dry tuned rotor gyro

    Science.gov (United States)

    Bahrami, K.

    1977-01-01

    The inertial attitude control system designed for the Voyager spacecraft, which will carry out flybys of Jupiter and Saturn in 1979 and 1981, respectively, is described. The attitude of the spacecraft in three-dimensional space will be measured by a Dry Inertial Reference Unit (DIRU) based on three identical two-degree-of-freedom dry gyros. A software estimation process has been developed to use DIRU data and other information to obtain optimum estimates of spacecraft position, velocity, and acceleration. The attitude of the spacecraft is corrected using these estimates by activating hydrazine thrusters. The operation of dry gyros is discussed, together with the network compensation techniques used in their associated capture loop to obtain a capture capability of 8 deg/sec and a frequency response of 10 Hz (3-dB point). The control law and estimation process are examined. Results of computer simulation studies of the performance of the attitude control system are presented.

  11. Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.

    Directory of Open Access Journals (Sweden)

    Mingying Huo

    Full Text Available 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.

  12. Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.

    Science.gov (United States)

    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.

  13. Demonstration of Single Axis Combined Attitude Control and Energy Storage Using Two Flywheels

    Science.gov (United States)

    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.

  14. Implicit attitudes towards homosexuality: reliability, validity, and controllability of the IAT.

    Science.gov (United States)

    Banse, R; Seise, J; Zerbes, N

    2001-01-01

    Two experiments were conducted to investigate the psychometric properties of an Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) that was adapted to measure implicit attitudes towards homosexuality. In a first experiment, the validity of the Homosexuality-IAT was tested using a known group approach. Implicit and explicit attitudes were assessed in heterosexual and homosexual men and women (N = 101). The results provided compelling evidence for the convergent and discriminant validity of the Homosexuality-IAT as a measure of implicit attitudes. No evidence was found for two alternative explanations of IAT effects (familiarity with stimulus material and stereotype knowledge). The internal consistency of IAT scores was satisfactory (alpha s > .80), but retest correlations were lower. In a second experiment (N = 79) it was shown that uninformed participants were able to fake positive explicit but not implicit attitudes. Discrepancies between implicit and explicit attitudes towards homosexuality could be partially accounted for by individual differences in the motivation to control prejudiced behavior, thus providing independent evidence for the validity of the implicit attitude measure. Neither explicit nor implicit attitudes could be changed by persuasive messages. The results of both experiments are interpreted as evidence for a single construct account of implicit and explicit attitudes towards homosexuality.

  15. On-orbit attitude control of the Cosmic Background Explorer (COBE)

    Science.gov (United States)

    Bramberg, B.; Croft, J.

    1985-01-01

    The way in which COBE (launched by the SS in late 1982) performs its attitude control is described, along with the design of its on-orbit system. COBE, to be situated in a 900 km high, sun-synchronous orbit, contains two unique control features: (1) the orientation of the spinning satellite is controlled to a sun-normal attitude in the sun/local vertical plane; and (2) pitch and roll control is maintained by a unique triaxial arrangement of reaction wheels, magnetic torque bars and sensors, located in the body's tranverse plane. Inherent in this triaxial configuration concept is a built-in redundancy that will maintain attitude control in the event of any single-point sensor/actuator component failure. Each of the three control drive electronics operates independently and directly of a system of dedicated sensors. This system functions independently of a computer or an ephemeris communication link, leading to greater reliability.

  16. On the semi-passive attitude control and propulsion of space vehicles using solar radiation pressure

    Science.gov (United States)

    Modi, V. J.

    1995-01-01

    This paper briefly reviews attitude dynamics and trajectory mechanics of spacecraft in the presence of environmental forces with particular emphasis on the solar radiation induced pressure and thermal effects on attitude dynamics. In general, the effect is destabilizing as indicated by a significant reduction in the size of the limiting integral manifold. However, several semi-passive controllers have been proposed which can use the environmental forces to advantage in stabilizing the system. Furthermore, the solar radiation-induced forces can be used to advantage for propulsion and trajectory transfer. Examples of contemporary interest illustrate effectiveness of the concepts in achieving desired attitude and trajectory.

  17. Attitude and Altitude Controller Design for Quad-Rotor Type MAVs

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available Micro air vehicles (MAVs have a wide application such as the military reconnaissance, meteorological survey, environmental monitoring, and other aspects. In this paper, attitude and altitude control for Quad-Rotor type MAVs is discussed and analyzed. For the attitude control, a new method by using three gyroscopes and one triaxial accelerometer is proposed to estimate the attitude angle information. Then with the approximate linear model obtained by system identification, Model Reference Sliding Mode Control (MRSMC technique is applied to enhance the robustness. In consideration of the relatively constant altitude model, a Linear Quadratic Gaussian (LQG controller is adopted. The outdoor experimental results demonstrate the superior stability and robustness of the controllers.

  18. General Attitude Control Algorithm for Spacecraft Equipped with Star Camera and Reaction Wheels

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Kulczycki, P.

    A configuration consisting of a star camera, four reaction wheels and magnetorquers for momentum unloading has become standard for many spacecraft missions. This popularity has motivated numerous agencies and private companies to initiate work on the design of an imbedded attitude control system...... realized on an integrated circuit. This paper considers two issues: slew maneuver with a feature of avoiding direct exposure of the camera's CCD chip to the Sun %, three-axis attitude control and optimal control torque distribution in a reaction wheel assembly. The attitude controller is synthesized...... applying the energy shaping technique, where the desired potential function is carefully designed using a physical insight into the nature of the problem. The system stability is thoroughly analyzed and the control performance simulated...

  19. Crew exploration vehicle (CEV) attitude control using a neural-immunology/memory network

    Science.gov (United States)

    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.

  20. A semi-physical simulation platform of attitude determination and control system for satellite

    Directory of Open Access Journals (Sweden)

    Yuanjin Yu

    2016-05-01

    Full Text Available A semi-physical simulation platform for attitude determination and control system is proposed to verify the attitude estimator and controller on ground. A simulation target, a host PC, many attitude sensors, and actuators compose the simulation platform. The simulation target is composed of a central processing unit board with VxWorks operating system and many input/output boards connected via Compact Peripheral Component Interconnect bus. The executable programs in target are automatically generated from the simulation models in Simulink based on Real-Time Workshop of MATLAB. A three-axes gyroscope, a three-axes magnetometer, a sun sensor, a star tracer, three flywheels, and a Global Positioning System receiver are connected to the simulation target, which formulates the attitude control cycle of a satellite. The simulation models of the attitude determination and control system are described in detail. Finally, the semi-physical simulation platform is used to demonstrate the availability and rationality of the control scheme of a micro-satellite. Comparing the results between the numerical simulation in Simulink and the semi-physical simulation, the semi-physical simulation platform is available and the control scheme successfully achieves three-axes stabilization.

  1. Combined spacecraft orbit and attitude control through extended Kalman filtering of magnetometer, gyro, and GPS measurements

    Directory of Open Access Journals (Sweden)

    Tamer Mekky Ahmed Habib

    2014-06-01

    Full Text Available The main goal of this research is to establish spacecraft orbit and attitude control algorithms based on extended Kalman filter which provides estimates of spacecraft orbital and attitude states. The control and estimation algorithms must be capable of dealing with the spacecraft conditions during the detumbling and attitude acquisition modes of operation. These conditions are characterized by nonlinearities represented by large initial attitude angles, large initial angular velocities, large initial attitude estimation error, and large initial position estimation error. All of the developed estimation and control algorithms are suitable for application to the next Egyptian scientific satellite, EGYPTSAT-2. The parameters of the case-study spacecraft are similar but not identical to the former Egyptian satellite EGYPTSAT-1. This is done because the parameters of EGYPTSAT-2 satellite have not been consolidated yet. The sensors utilized are gyro, magnetometer, and GPS. Gyro and magnetometer are utilized to provide measurements for the estimates of spacecraft attitude state vector where as magnetometer and GPS are utilized to provide measurements for the estimates of spacecraft orbital state vector.

  2. Attitude Control Synthesis for Small Satellites Using Gradient Method. Part II Linear Equations, Synthesis

    Directory of Open Access Journals (Sweden)

    Adrian CHELARU

    2013-03-01

    Full Text Available In order to continue paper [5] which presented the nonlinear equations of the movement for small satellite, this paper presents some aspects regarding the synthesis of the attitude control. Afterthe movement equation linearization, the stability and command matrixes will be established and by using the gradient methods controller we will obtain them. Two attitude control cases will beanalysed: the reaction wheels and the micro thrusters. The results will be used in the project European Space Moon Orbit - ESMO, founded by the European Space Agency in which the POLITEHNICA University of Bucharest is involved.

  3. Improvement of helicopter attitude stability by active control of the conventional swash plate

    Science.gov (United States)

    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.

  4. X-33 Attitude Control Using the XRS-2200 Linear Aerospike Engine

    Science.gov (United States)

    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.

  5. On-orbit verification of fuel-free attitude control system for spinning solar sail utilizing solar radiation pressure

    Science.gov (United States)

    Funase, Ryu; Shirasawa, Yoji; Mimasu, Yuya; Mori, Osamu; Tsuda, Yuichi; Saiki, Takanao; Kawaguchi, Jun'ichiro

    2011-12-01

    This paper introduces a new attitude control system for a solar sail, which leverages solar radiation pressure. This novel system achieves completely fuel-free and oscillation-free attitude control of a flexible spinning solar sail. This system consists of thin-film-type devices that electrically control their optical parameters such as reflectivity to generate an imbalance in the solar radiation pressure applied to the edge of the sail. By using these devices, minute and continuous control torque can be applied to the sail to realize very stable and fuel-free attitude control of the large and flexible membrane. The control system was implemented as an optional attitude control system for small solar power sail demonstrator named IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). In-orbit attitude control experiments were conducted, and the performance of the controller was successfully verified in comparison with the ground-based analytical performance estimation.

  6. Smoking behaviors and attitudes during adolescence prospectively predict support for tobacco control policies in adulthood.

    Science.gov (United States)

    Macy, Jonathan T; Chassin, Laurie; Presson, Clark C

    2012-07-01

    Several cross-sectional studies have examined factors associated with support for tobacco control policies. The current study utilized a longitudinal design to test smoking status and attitude toward smoking measured in adolescence as prospective predictors of support for tobacco control policies measured in adulthood. Participants (N = 4,834) were from a longitudinal study of a Midwestern community-based sample. Hierarchical multiple regression analyses tested adolescent smoking status and attitude toward smoking as prospective predictors (after controlling for sociodemographic factors, adult smoking status, and adult attitude toward smoking) of support for regulation of smoking in public places, discussion of the dangers of smoking in public schools, prohibiting smoking in bars, eliminating smoking on television and in movies, prohibiting smoking in restaurants, and increasing taxes on cigarettes. Participants who smoked during adolescence demonstrated more support for discussion of the dangers of smoking in public schools and less support for increasing taxes on cigarettes but only among those who smoked as adults. Those with more positive attitudes toward smoking during adolescence demonstrated less support as adults for prohibiting smoking in bars and eliminating smoking on television and in movies. Moreover, a significant interaction indicated that those with more positive attitudes toward smoking as adolescents demonstrated less support as adults for prohibiting smoking in restaurants, but only if they became parents as adults. This study's findings suggest that interventions designed to deter adolescent smoking may have future benefits in increasing support for tobacco control policies.

  7. Dynamics and Control of Attitude, Power, and Momentum for a Spacecraft Using Flywheels and Control Moment Gyroscopes

    Science.gov (United States)

    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.

  8. Attitude Control of Quad-rotor by Improving the Reliability of Multi-Sensor System

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Dong Hyeon; Chong, Kil To [Chon-bok National University, Jeonju (Korea, Republic of); Park, Jong Ho [Seonam University, Namwon (Korea, Republic of); Ryu, Ji Hyoung [ETRI, Daejeon (Korea, Republic of)

    2015-05-15

    This paper presents the results of study for improving the reliability of quadrotor attitude control by applying a multi-sensor along with a data fusion algorithm. First, a mathematical model of the quadrotor dynamics was developed. Then, using the quadrotor mathematical model, simulations were performed using the improved reliability multi-sensor data as the inputs. From the simulation results, we designed a Gimbal-equipped quadrotor system. With the quadrotor in a hover state, we performed experiments according to the angle change of the user's specifications . We then calculated the attitude control data from the actual experimental data. Furthermore, with additional simulations, we verified the performance of the designed quadrotor attitude control system with multiple sensors.

  9. Adaptive backstepping control for three axis microsatellite attitude pointing under actuator faults

    Science.gov (United States)

    MOHAMMED, M. A. SI; BOUSSADIA, H.; BELLAR, A.; ADNANE, A.

    2017-01-01

    This paper presents the design of Low Earth Orbit (LEO) micro-satellite attitude controller using reaction wheels, and under actuator faults. Firstly, a backstepping controller is developed when the actuator is fault-free. Then, a fault tolerant controller is designed to compensate the actuator fault. Two types of this latter are considered (additive and multiplicative faults). The presented control strategy is based on adaptive backstepping technique. The simulation results clearly demonstrate the effectiveness of the presented technique.

  10. Robust Control Allocation for Spacecraft Attitude Stabilization under Actuator Faults and Uncertainty

    Directory of Open Access Journals (Sweden)

    Aihua Zhang

    2014-01-01

    Full Text Available A robust control allocation scheme is developed for rigid spacecraft attitude stabilization in the presence of actuator partial loss fault, actuator failure, and actuator misalignment. First, a neural network fault detection scheme is proposed, Second, an adaptive attitude tracking strategy is employed which can realize fault tolerance control under the actuator partial loss and actuator failure within λmin⁡=0.5. The attitude tracking and faults detection are always here during the procedure. Once the fault occurred which could not guaranteed the attitude stable for 30 s, the robust control allocation strategy is generated automatically. The robust control allocation compensates the control effectiveness uncertainty which caused the actuator misalignment. The unknown disturbances, uncertain inertia matrix, and even actuator error with limited actuators are all considered in the controller design process. All are achieved with inexpensive online computations. Numerical results are also presented that not only highlight the closed-loop performance benefits of the control law derived here but also illustrate its great robustness.

  11. Attitude output feedback control for rigid spacecraft with finite-time convergence.

    Science.gov (United States)

    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.

  12. Development of a Hardware-in-the-loop Simulator for Spacecraft Attitude Control Using Thrusters

    Directory of Open Access Journals (Sweden)

    Dong-Wook Koh

    2009-03-01

    Full Text Available In this study, a Hardware-In-the-Loop (HIL simulator using thrusters is developed to validate the spacecraft attitude system. To control the attitude of the simulator, eight cold gas thrusters are aligned with roll, pitch and yaw axis. Also linear actuators are applied to the HIL simulator for automatic mass balancing to compensate the center of mass offset from the center of rotation. The HIL simulator consists of an embedded computer (Onboard PC for simulator system control, a wireless adapter for wireless network, a rate gyro sensor to measure 3-axis attitude of the simulator, an inclinometer to measure horizontal attitude, and a battery set to supply power for the simulator independently. For the performance test of the HIL simulator, a bang-bang controller and Pulse-Width Pulse-Frequency (PWPF modulator are evaluated successfully. The maneuver of 68 deg. in yaw axis is tested for the comparison of the both controllers. The settling time of the bang -bang controller is faster than that of the PWPF modulator by six seconds in the experiment. The required fuel of the PWPF modulator is used as much as 51% of bang-bang controller in the experiment. Overall, the HIL simulator is appropriately developed to validate the control algorithms using thrusters.

  13. Model predictive and reallocation problem for CubeSat fault recovery and attitude control

    Science.gov (United States)

    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.

  14. Self-control, perceived opportunity, and attitudes as predictors of academic dishonesty.

    Science.gov (United States)

    Bolin, Aaron U

    2004-03-01

    Academic dishonesty is a persistent and pervasive problem on college campuses. Researchers have suggested a variety of factors that influence academic dishonesty. The present study is an examination of the roles of self-control, attitude toward academic dishonesty, and perceived opportunity in predicting academic dishonesty. The dataset consisted of 853 survey responses from university students across the United States. The results showed that attitude toward academic dishonesty mediated the relationship between self-control and academic dishonesty and also between perceived opportunity and academic dishonesty. Implications of these findings are briefly discussed.

  15. Microsatellite Attitude Determination and Control Subsystem Design and Implementation: Software-in-the-Loop Approach

    Directory of Open Access Journals (Sweden)

    Ho-Nien Shou

    2014-01-01

    Full Text Available The paper describes the development of a microsatellite attitude determination and control subsystem (ADCS and verification of its functionality by software-in-the-loop (SIL method. The role of ADCS is to provide attitude control functions, including the de-tumbling and stabilizing the satellite angular velocity, and as well as estimating the orbit and attitude information during the satellite operation. In Taiwan, Air Force Institute of Technology (AFIT, dedicating for students to design experimental low earth orbit micro-satellite, called AFITsat. For AFITsat, the operation of the ADCS consists of three modes which are initialization mode, detumbling mode, and normal mode, respectively. During the initialization mode, ADCS collects the early orbit measurement data from various sensors so that the data can be downlinked to the ground station for further analysis. As particularly emphasized in this paper, during the detumbling mode, ADCS implements the thrusters in plus-wide modulation control method to decrease the satellite angular velocity. ADCS provides the attitude determination function for the estimation of the satellite state, during normal mode. The three modes of microsatellite adopted Kalman filter algorithm estimate microsatellite attitude. This paper will discuss using the SIL validation ADCS function and verify its feasibility.

  16. Affectionless control by the same-sex parents increases dysfunctional attitudes about achievement.

    Science.gov (United States)

    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.

  17. Finite-Time Reentry Attitude Control Using Time-Varying Sliding Mode and Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Xuzhong Wu

    2015-01-01

    Full Text Available This paper presents the finite-time attitude control problem for reentry vehicle with redundant actuators in consideration of planet uncertainties and external disturbances. Firstly, feedback linearization technique is used to cancel the nonlinearities of equations of motion to construct a basic mode for attitude controller. Secondly, two kinds of time-varying sliding mode control methods with disturbance observer are integrated with the basic mode in order to enhance the control performance and system robustness. One method is designed based on boundary layer technique and the other is a novel second-order sliding model control method. The finite-time stability analyses of both resultant closed-loop systems are carried out. Furthermore, after attitude controller produces the torque commands, an optimization control allocation approach is introduced to allocate them into aerodynamic surface deflections and on-off reaction control system thrusts. Finally, the numerical simulation results demonstrate that both of the time-varying sliding mode control methods are robust to uncertainties and disturbances without chattering phenomenon. Moreover, the proposed second-order sliding mode control method possesses better control accuracy.

  18. Analysis of the TDRS multiple access system for possible use as an attitude control system sensor

    Science.gov (United States)

    Blevins, Bruce Allyn; Sank, Victor J.

    1993-01-01

    A member of the constellation of TDR satellites (TDRS) has experienced a failure of its prime earth sensor. Failure of the remaining earth sensor could result in the inability of the satellite to control its attitude and provide user services. Loss of the satellite would be a serious event. The multiple access (MA) antenna array on the TDRS has been proposed for use as a backup sensor for the attitude control system. This paper describes our analysis of the performance of the MA array as an interferometer used for accurate attitude determination. A least squares fit of a plane to the MA phase information appears to represent the TDRS body roll and pitch within about 0.1 deg. This is sufficient for SGL pointing and MA and SSA user services. Analytic improvements that include ionospheric correction may yield sufficient accuracy for KSA user services.

  19. Modeling the coupling effect of jitter and attitude control on TDICCD camera imaging

    Science.gov (United States)

    Li, Yulun; Yang, Zhen; Ma, Xiaoshan; Ni, Wei

    2016-10-01

    The vibration has an important influence on space-borne TDICCD imaging quality. It is generally aroused by an interaction between satellite jitter and attitude control. Previous modeling for this coupling relation is mainly concentrating on accurate modal analysis, transfer path and damping design, etc. Nevertheless, when controlling attitude, the coupling terms among three body axes are usually ignored. This is what we try to study in this manuscript. Firstly, a simplified formulation dedicated to this problem is established. Secondly, we use Dymola 2016 to execute the simulation model profiting Modelica synchronous feature, which has been proposed in recent years. The results demonstrate that the studied effect can introduce additional oscillatory modes and lead the attitude stabilization process slower. In addition, when fully stabilized, there seems time-statistically no difference but it still intensifies the motion-blur by a tiny amount. We state that this effect might be worth considering in image restoration.

  20. The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

    Directory of Open Access Journals (Sweden)

    Mingying Huo

    2017-01-01

    Full Text Available Displaced solar orbits for spacecraft propelled by electric sails are investigated. Since the propulsive thrust is induced by the sail attitude, the orbital and attitude dynamics of electric-sail-based spacecraft are coupled and required to be investigated together. However, the coupled dynamics and control of electric sails have not been discussed in most published literatures. In this paper, the equilibrium point of the coupled dynamical system in displaced orbit is obtained, and its stability is analyzed through a linearization. The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit system. Numerical simulations show that the proposed strategy can control the coupled system and a small torque can stabilize both the attitude and orbit. In order to generate the control force and torque, the voltage distribution problem is studied in an optimal framework. The numerical results show that the control force and torque of electric sail can be realized by adjusting the voltage distribution of charged tethers.

  1. Maternal and Paternal Psychological Control as Moderators of the Link between Peer Attitudes and Adolescents’ Risky Sexual Behavior

    Science.gov (United States)

    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

  2. Fuzzy based attitude controller for flexible spacecraft with on/off thrusters

    Science.gov (United States)

    Knapp, Roger Glenn

    1993-05-01

    A fuzzy-based attitude controller is designed for attitude control of a generic spacecraft with on/off thrusters. The controller is comprised of packages of rules dedicated to addressing different objectives (e.g., disturbance rejection, low fuel consumption, avoiding the excitation of flexible appendages, etc.). These rule packages can be inserted or removed depending on the requirements of the particular spacecraft and are parameterized based on vehicle parameters such as inertia or operational parameters such as the maneuvering rate. Individual rule packages can be 'weighted' relative to each other to emphasize the importance of one objective relative to another. Finally, the fuzzy controller and rule packages are demonstrated using the high-fidelity Space Shuttle Interactive On-Orbit Simulator (IOS) while performing typical on-orbit operations and are subsequently compared with the existing shuttle flight control system performance.

  3. Attitude angle anti-windup control of small size unmanned helicopter

    Science.gov (United States)

    Shao, Taizhou; Long, Haihui; Zhao, Jiankang; Xia, Xuan; Yang, Guang

    2017-01-01

    This paper researches the small-size unmanned helicopter attitude control problem with actuator saturation limit. Traditional approach for this problem is often based on an accurate dynamic model which is complicated and difficult to achieve in engineering. In this paper, we propose an anti-windup PID approach which does not rely on sophicated helicopter dynamic model. The anti-windup PID controller is established by adding a phase-lead compensator to the conventional PID controller. The performance and merits of this proposed controller are exemplified by the simulations between the conventional PID controller and the anti-windup PID controller.

  4. Pengaruh Attitude, Subjective Norm, Perceived Behavioral Control Pelanggan Non-muslim terhadap Intention To Purchase

    OpenAIRE

    Andryani, Dwinta; Kurniawati

    2015-01-01

    Penelitian ini dilakukan untuk menganalisa pengaruh Attitude, Subjective Norm, PerceivedBehavioral Control terhadap Intention to Purchase. Data dikumpulkan langsung melaluipenyebaran kuesioner kepada 170 orang responden. Teknik pengambilan sampel dalam penelitianini adalah dengan menggunakan purposive sampling. Hasil empiris dari penelitian inimenggunakan program Statistical Package for the Social Science (SPSS) dengan metode analisisstructural equation model (SEM). Hasil pengujian hipotesis ...

  5. A comparison of dysfunctional attitudes in substance abusers and control group and its psychological outcome

    Directory of Open Access Journals (Sweden)

    2008-11-01

    This research was carried out to assess the role of dysfunctional attitudes, outcomes of psychology in substance abuse behaviors of subject were referred to addiction treatment center in the city of Bandar Abbas, and to compare the with the control group. Methods: This is a retrospective study in which 100 subject substance abusers were compared with 100 subject s of control group who were selected using convenience sampling and were also demographically matched. Data were gathered using a demographic questionnaire, clinical interview, dysfunctional attitudes scale (DAS, Depression Anxiety Stress Scale (DASS. The data were analyzed via descriptive statistic method, T- Test and chi-square and variance analysis. Findings: Findings indicated that in comparison with control group, subject of substance abusers had experienced more stress, anxiety, depression, had shown a cognitively more percent of them dysfunctional attitudes in comparison with control group. Results: The results suggested that the dysfunctional attitudes could be as a Vulnerability Factor that increase abuse of substance consequently use of cognitive therapy could be helpful and effective in prevention and treatment of the addicts.

  6. Interrelationships of Study Habits and Attitudes, Locus of Control, Motivation Achievement Tendencies and Academic Achievement.

    Science.gov (United States)

    Gadzella, Bernadette M.; And Others

    The study investigated (a) relationships between measures on study habits and attitudes, locus of control, achieving tendency, and semester grade-point averages (SGPA), (b) differences between the sexes on the above mentioned variables, and (c) best predictor of SGPA. The subjects were 39 males and 81 females. There were a number of significant…

  7. The Attitudes & Beliefs on Classroom Control Inventory-Revised and Revisited: A Continuation of Construct Validation

    Science.gov (United States)

    Martin, Nancy K.; Yin, Zenong; Mayall, Hayley

    2008-01-01

    The purpose of this study was to report the psychometric properties of the revised Attitudes and Beliefs of Classroom Control Inventory (ABCC-R). Data were collected from 489 participants via the ABCC-R, Teacher Efficacy Scale, Problems in School Questionnaire, and a demographic questionnaire. Results were in keeping with the construct. The…

  8. Community Involvement, Perceived Control, and Attitudes toward Aging among Lesbians and Gay Men

    Science.gov (United States)

    Hostetler, Andrew J.

    2012-01-01

    A person-environment approach was used to explore the relationship between community involvement and attitudes toward aging among middle-age and older lesbians and gay men. Specifically, this study investigated the relationships between participation in gay community activities, perceived control, and aging-related concerns among two…

  9. Children's Eating Attitudes and Behaviour: A Study of the Modelling and Control Theories of Parental Influence

    Science.gov (United States)

    Brown, Rachael; Ogden, Jane

    2004-01-01

    The present study compared the modelling and control theories of parental influence on children's eating attitudes and behaviour with a focus on snack foods. Matched questionnaires describing reported snack intake, eating motivations and body dissatisfaction were completed by 112 parent/child pairs. Parents completed additional items relating to…

  10. Locus of Control and Computer Attitude: The Effect of User Involvement.

    Science.gov (United States)

    Hawk, Stephen R.

    1989-01-01

    Describes study that was conducted to investigate the relationship between locus of control and user attitude toward computer based information systems (CBIS) used at work. The impact of user involvement is examined, the hypotheses tested are described, and implications for introducing CBIS into organizations are discussed. (14 references) (LRW)

  11. Tobacco Control Policy Advocacy Attitudes and Self-Efficacy among Ethnically Diverse High School Students

    Science.gov (United States)

    Ramirez, Amelie G.; Velez, Luis F.; Chalela, Patricia; Grussendorf, Jeannie; McAlister, Alfred L.

    2006-01-01

    This study applied self-efficacy theory to assess empowerment to advocate on behalf of tobacco control policies. The Youth Tobacco Survey with added policy advocacy self-efficacy, attitudes, and outcome expectations scales was given to 9,177 high school students in Texas. Asians showed the lowest prevalence of experimentation and current smoking,…

  12. Using Automatic Code Generation in the Attitude Control Flight Software Engineering Process

    Science.gov (United States)

    McComas, David; O'Donnell, James R., Jr.; Andrews, Stephen F.

    1999-01-01

    This paper presents an overview of the attitude control subsystem flight software development process, identifies how the process has changed due to automatic code generation, analyzes each software development phase in detail, and concludes with a summary of our lessons learned.

  13. Analysis of the Command and Control Segment (CCS) attitude estimation algorithm

    Science.gov (United States)

    Stockwell, Catherine

    1993-01-01

    This paper categorizes the qualitative behavior of the Command and Control Segment (CCS) differential correction algorithm as applied to attitude estimation using simultaneous spin axis sun angle and Earth cord length measurements. The categories of interest are the domains of convergence, divergence, and their boundaries. Three series of plots are discussed that show the dependence of the estimation algorithm on the vehicle radius, the sun/Earth angle, and the spacecraft attitude. Common qualitative dynamics to all three series are tabulated and discussed. Out-of-limits conditions for the estimation algorithm are identified and discussed.

  14. Design of Attitude Control Actuators for a Simulated Spacecraft

    Science.gov (United States)

    2011-03-24

    however, there are many dual-use applications, such as regenerative braking technology and flywheel energy storage. The reaction wheel system on Simsat...wheel and thruster control systems . The control moment gyroscope array was required to interface with SimSat’s existing structure, power supply, and...Captain Ryan Snider for sharing his lessons about Simsat, practical knowledge, and valuable hands-on time with someone who knew the system . Next, I’d

  15. Improving knowledge and attitudes towards depression: a controlled trial among Chinese medical students.

    Science.gov (United States)

    Rong, Ye; Glozier, Nick; Luscombe, Georgina M; Davenport, Tracey A; Huang, Yueqin; Hickie, Ian B

    2011-03-08

    Establishing an evidence-based method of improving knowledge and attitudes concerning depression has been identified as a priority in Chinese medical education. The purpose of this study was to determine whether a self-directed learning strategy as a part of student-centred education improved knowledge of and attitudes towards depression among Chinese medical students. A controlled trial in which 205 medical students were allocated to one of two groups: didactic teaching (DT) group or a combined didactic teaching and self-directed learning (DT/SDL) group. The DT/SDL group continued having a series of learning activities after both groups had a lecture on depression together. Student's knowledge and attitudes were assessed immediately after the activities, one month and six months later. The intervention (DT/SDL) group showed substantially greater improvements in recognition of depression as a major health issue and identifying helpful treatments than the DT group. Only the DT/SDL group demonstrated any improvement in attitudes. This improvement was sustained over six months. Self-directed learning is an effective education strategy in improving medical students' knowledge of and attitudes towards depression.

  16. Improving Knowledge and Attitudes towards Depression: a controlled trial among Chinese medical students

    Directory of Open Access Journals (Sweden)

    Davenport Tracey A

    2011-03-01

    Full Text Available Abstract Background Establishing an evidence-based method of improving knowledge and attitudes concerning depression has been identified as a priority in Chinese medical education. The purpose of this study was to determine whether a self-directed learning strategy as a part of student-centred education improved knowledge of and attitudes towards depression among Chinese medical students. Methods A controlled trial in which 205 medical students were allocated to one of two groups: didactic teaching (DT group or a combined didactic teaching and self-directed learning (DT/SDL group. The DT/SDL group continued having a series of learning activities after both groups had a lecture on depression together. Student's knowledge and attitudes were assessed immediately after the activities, one month and six months later. Results The intervention (DT/SDL group showed substantially greater improvements in recognition of depression as a major health issue and identifying helpful treatments than the DT group. Only the DT/SDL group demonstrated any improvement in attitudes. This improvement was sustained over six months. Conclusions Self-directed learning is an effective education strategy in improving medical students' knowledge of and attitudes towards depression.

  17. Coupled Attitude and Orbit Dynamics and Control in Formation Flying Systems

    Science.gov (United States)

    Xu, Yun-Jun; Fitz-Coy, Norman; Mason, Paul

    2003-01-01

    Formation flying systems can range from global constellations offering extended service coverage to clusters of highly coordinated vehicles that perform distributed sensing. Recently, the use of groups of micro-satellites in the areas of near Earth explorations, deep space explorations, and military applications has received considerable attention by researchers and practitioners. To date, most proposed control strategies are based on linear models (e.g., Hill-Clohessy-Wiltshire equations) or nonlinear models that are restricted to circular reference orbits. Also, all models in the literature are uncoupled between relative position and relative attitude. In this paper, a generalized dynamic model is proposed. The reference orbit is not restricted to the circular case. In this formulation, the leader or follower satellite can be in either a circular or an elliptic orbit. In addition to maintaining a specified relative position, the satellites are also required to maintain specified relative attitudes. Thus the model presented couples vehicle attitude and orbit requirements. Orbit perturbations are also included. In particular, the J(sub 2) effects are accounted in the model. Finally, a sliding mode controller is developed and used to control the relative attitude of the formation and the simulation results are presented.

  18. Guidance and adaptive-robust attitude & orbit control of a small information satellite

    Science.gov (United States)

    Somov, Ye.; Butyrin, S.; Somov, S.; Somova, T.; Testoyedov, N.; Rayevsky, V.; Titov, G.; Yakimov, Ye.; Ovchinnikov, A.; Mathylenko, M.

    2017-01-01

    We consider a small information satellite which may be placed on an orbit with altitude from 600 up to 1000 km. The satellite attitude and orbit control system contains a strap-down inertial navigation system, cluster of four reaction wheels, magnetic driver and a correcting engine unit with eight electro-reaction engines. We study problems on design of algorithms for spatial guidance, in-flight identification and adaptive-robust control of the satellite motion on sun-synchronous orbit.

  19. A Comparative Study of Actuator Configurations for Satellite Attitude Control

    Directory of Open Access Journals (Sweden)

    Raymond Kristiansen

    2005-10-01

    Full Text Available In this paper a controllability study of different actuator configurations consisting of magnetic torquers, reaction wheels and a gravity boom is presented. The theoretical analysis is performed with use of controllability gramians, and simulation results with the different configurations are presented and compared regarding settling time and power consumption to substantiate the theoretical analysis. A reference model is also introduced to show how the power consumption can he lowered to the same magnitude as when magnetic torquers are used, without degrading the satellite response significantly.

  20. Knowledge, Attitude and Performance of Shiraz General Dentists about Infection Control Principles during Preparing Intraoral Radiographies

    Directory of Open Access Journals (Sweden)

    Abdolaziz Hagh Negahdar

    2017-02-01

    Full Text Available Background & Objective: Infection control in dental centers is affected by the persons’ attitude and knowledge about mechanisms of infection transmission. This study was designed to evaluate the knowledge and the attitude of Shiraz dentists about infection control during intraoral radiographies preparation. Materials & Methods: In this cross-sectional, and analytical research, the attitude and the knowledge of 45 male and 25 female, randomly selected dentists, were obtained through completion of a researcher- planed questioner which its validity and reliability had been confirmed. Data were analyzed using Cronbach`s alpha, one-way ANOVA, student’s t-test, and Pearson’s correlation coefficient in SPSS (V.21. Results: The average of the dentists’ age was 40.59±10.72 and their average occupational experience was 13.49±9.75 years. The mean score obtained for knowledge about infection control during intraoral radiographic procedures was less than fifty percent of total obtainable score, and was assessed as weak knowledge. There was no significant difference in the level of knowledge between studied male and female dentists (P>0.05. In addition, no significant relationship was detected between level, age/experience, and the university of education (P>0.05. The attitude of the dentists about infection control during intraoral radiography preparation assessed as moderate to good level. Conclusions: The results showed that the main reason for the present problems is insufficient knowledge of the dentists in related subjects. Therefore, the solution, which is recommended among dentists, is to raise their awareness and to change their attitudes and culture in order to improve their performance.

  1. Performance quantification of heliogyro solar sails using structural, attitude, and orbital dynamics and control analysis

    Science.gov (United States)

    Guerrant, Daniel Vernon

    Solar sails enable or enhance exploration of a variety of destinations both within and without the solar system. The heliogyro solar sail architecture divides the sail into blades spun about a central hub and centrifugally stiffened. The resulting structural mass savings can often double acceleration verses kite-type square sails of the same mass. Pitching the blades collectively and cyclically, similar to a helicopter, creates attitude control moments and vectors thrust. The principal hurdle preventing heliogyros' implementation is the uncertainty in their dynamics. This thesis investigates attitude, orbital and structural control using a combination of analytical studies and simulations. Furthermore, it quantifies the heliogyro's ability to create attitude control moments, change the thrust direction, and stably actuate blade pitch. This provides engineers a toolbox from which to estimate the heliogyro's performance and perform trades during preliminary mission design. It is shown that heliogyros can create an attitude control moment in any direction from any orientation. While their large angular momentum limits attitude slewing to only a few degrees per hour, cyclic blade pitching can slew the thrust vector within a few minutes. This approach is only 13% less efficient than slewing a square sail during Earth escape, so it does not offset the overall acceleration benefits of heliogyros. Lastly, a root pitch motor should be able to settle torsional disturbances within a few rotations and achieve thrust performance comparable to that of flat blades. This work found no significant dynamic hurdles for heliogyros, and it provides key insight into their practical capabilities and limitations for future mission designers.

  2. Attitude control of an underactuated spacecraft using quaternion feedback regulator and tube-based MPC

    Science.gov (United States)

    Mirshams, M.; Khosrojerdi, M.

    2017-03-01

    Feasibility of achieving 3-axis stabilization of an asymmetric spacecraft for cases where there is no control available in one axis (underactuated spacecraft) is explored in this paper. A novel control design methodology is presented which can stabilize the underactuated spacecraft and steer it to the origin. A passive fault tolerant control (FTC) is defined which controls and maintains the attitude of the spacecraft near the desired point in presence of uncertainties, disturbances, control constraints and actuator faults. Considering the general conditions of the underactuated spacecraft, a hybrid controller combining a quaternion feedback regulator (QFR) with a tube-based model predictive controller (MPC) is developed based on the nonlinear kinematic and dynamic equations of the spacecraft motion. The hybrid controller is composed of two control stages. At the first stage, QFR decreases the angular velocities and brings the state vector to an acceptable region for the next stage. Then, tube-based MPC solves two optimal control problems, a standard problem for the nominal system to define a central guide path, and an ancillary problem to steer the state vector towards the central path with semi-optimal control effort. Numerical simulation results obtained for the underactuated spacecraft merely indicate effectiveness of the proposed attitude control method.

  3. Finite-time sliding mode attitude control for a reentry vehicle with blended aerodynamic surfaces and a reaction control system

    Directory of Open Access Journals (Sweden)

    Geng Jie

    2014-08-01

    Full Text Available This paper proposes a finite-time robust flight controller, targeting for a reentry vehicle with blended aerodynamic surfaces and a reaction control system (RCS. Firstly, a novel finite-time attitude controller is pointed out with the introduction of a nonsingular finite-time sliding mode manifold. The attitude tracking errors are mathematically proved to converge to zero within finite time which can be estimated. In order to improve the performance, a second-order finite-time sliding mode controller is further developed to effectively alleviate chattering without any deterioration of robustness and accuracy. Moreover, an optimization control allocation algorithm, using linear programming and a pulse-width pulse-frequency (PWPF modulator, is designed to allocate torque commands for all the aerodynamic surface deflections and on–off switching-states of RCS thrusters. Simulations are provided for the reentry vehicle considering uncertain parameters and external disturbances for practical purposes, and the results demonstrate the effectiveness and robustness of the attitude control system.

  4. Information Fusion-Based Optimal Attitude Control for an Alterable Thrust Direction Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Ziyang Zhen

    2013-01-01

    Full Text Available Attitude control is the inner-loop and the most important part of the automatic flight control system of an unmanned aerial vehicle (UAV. The information fusion-based optimal control method is applied in a UAV flight control system in this work. Firstly, a nonlinear model of alterable thrust direction UAV (ATD-UAV is established and linearized for controller design. The longitudinal controller and lateral controller are respectively designed based on information fusion-based optimal control, and then the information fusion flight control system is built up. Finally, the simulation of a nonlinear model described as ATD-UAV is carried out, the results of which show the superiority of the information fusion-based control strategy when compared to the single-loop design method. We also show that the ATD technique improves the anti-disturbance capacity of the UAV.

  5. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  6. Attitude towards computer-based learning: determinants as revealed by a controlled interventional study.

    Science.gov (United States)

    Hahne, Amina Katharina; Benndorf, Ralf; Frey, Peter; Herzig, Stefan

    2005-09-01

    Curriculum-wide implementation of computer-based learning (CBL) in undergraduate medical education remains elusive. Unlike many pilot tests of singular learning programmes, dropout rates are high and acceptance seems low in the long run. We studied the effect of a new CBL programme, suitable for curriculum-wide implementation, on Year 3 medical students' attitudes towards CBL. Students from 2 universities participating in a mandatory pharmacology course were given access to a CBL programme covering cardiovascular drug therapy in a controlled randomised study (n = 167). Learner properties and attitude towards CBL were measured using psychometric scales, and knowledge by multiple-choice questions (pre- and post-test). Attitude towards CBL worsened in the CBL group (n = 70). Individual learners' properties did not explain this effect. The perceived programme quality was rated only 'average', which may contribute to the lower post-test values of attitude towards CBL. Learning outcomes were similar between the control group (n = 97) and students using CBL (n = 44). Learning efforts were shifted from self-study towards CBL. The initial enthusiasm of students was not maintained when using a programme designed to complement or even replace traditional teaching. Curriculum-wide implementation of CBL might be hampered by the discouragement of users.

  7. Asymptotic stability of a satellite with electrodynamic attitude control in the orbital frame

    Science.gov (United States)

    Aleksandrov, A. Yu.; Tikhonov, A. A.

    2017-10-01

    A satellite in a circular near-Earth orbit is under consideration. The three-axis stabilization of the satellite in the orbital coordinate system with the use of electrodynamic attitude control system is studied. No constraints are imposed on the Earth's magnetic field approximation. The gravity gradient disturbing torque acting on the satellite attitude dynamics is taken into account as the largest disturbing torque. With the use of the Lyapunov direct method, conditions under which electrodynamic control solves the problem are obtained. The restrictions on the control parameter values for which one can guarantee the asymptotic stability of the programmed satellite motion are found and represented in an explicit form. Comparison of the results of numerical simulation and analytical investigation demonstrate effectiveness of the proposed approach.

  8. Design development of the Apollo command and service module thrust vector attitude control systems

    Science.gov (United States)

    Peters, W. H.

    1978-01-01

    Development of the Apollo thrust vector control digital autopilot (TVC DAP) was summarized. This is the control system that provided pitch and yaw attitude control during velocity change maneuvers using the main rocket engine on the Apollo service module. A list of ten primary functional requirements for this control system are presented, each being subordinate to a more general requirement appearing earlier on the list. Development process functions were then identified and the essential information flow paths were explored. This provided some visibility into the particular NASA/contractor interface, as well as relationships between the many individual activities.

  9. Public attitudes towards smoking and tobacco control policy in Russia

    Science.gov (United States)

    Danishevski, Kirill; Gilmore, Anna; McKee, Martin

    2014-01-01

    Background Since the political transition in 1991, Russia has been targeted intensively by the transnational tobacco industry. Already high smoking rates among men have increased further; traditionally low rates among women have more than doubled. The tobacco companies have so far faced little opposition as they shape the discourse on smoking in Russia. This paper asks what ordinary Russians really think about possible actions to reduce smoking. Methods A representative sample of the Russian population (1600 respondents) was interviewed face-to-face in November 2007. Results Only 14% of respondents considered tobacco control in Russia adequate, while 37% felt that nothing was being done at all. There was support for prices keeping pace with or even exceeding inflation. Over 70% of all respondents favoured a ban on sales from street kiosks, while 56% believed that existing health warnings (currently 4% of front and back of packs) were inadequate. The current policy of designating a few tables in bars and restaurants as non-smoking was supported by less than 10% of respondents, while almost a third supported a total ban, with 44% supporting provision of equal space for smokers and non-smokers. Older age, non-smoking status and living a smaller town all emerged as significantly associated with the propensity to support of antismoking measures. The tobacco companies were generally viewed as behaving like most other companies in Russia, with three-quarters believing that they definitely or maybe bribe politicians. Knowledge of impact of smoking on health was limited with significant underestimation of dangers and addictive qualities of tobacco. A third believed that light cigarettes are safer than normal. Conclusion The majority of the Russian population would support considerable strengthening of tobacco control policies but there is also a need for effective public education campaigns. PMID:18653793

  10. The Connection between Environmental Attitude-Behavior Gap and Other Individual Inconsistencies: A Call for Strengthening Self-Control

    Science.gov (United States)

    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…

  11. Inertial attitude control of a bat-like morphing-wing air vehicle.

    Science.gov (United States)

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-03-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (ϕ) and pitch (θ) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms⁻¹.

  12. Real-Time Attitude Control Algorithm for Fast Tumbling Objects under Torque Constraint

    Science.gov (United States)

    Tsuda, Yuichi; Nakasuka, Shinichi

    This paper describes a new control algorithm for achieving any arbitrary attitude and angular velocity states of a rigid body, even fast and complicated tumbling rotations, under some practical constraints. This technique is expected to be applied for the attitude motion synchronization to capture a non-cooperative, tumbling object in such missions as removal of debris from orbit, servicing broken-down satellites for repairing or inspection, rescue of manned vehicles, etc. For this objective, we have introduced a novel control algorithm called Free Motion Path Method (FMPM) in the previous paper, which was formulated as an open-loop controller. The next step of this consecutive work is to derive a closed-loop FMPM controller, and as the preliminary step toward the objective, this paper attempts to derive a conservative state variables representation of a rigid body dynamics. 6-Dimensional conservative state variables are introduced in place of general angular velocity-attitude angle representation, and how to convert between both representations are shown in this paper.

  13. Finite time attitude takeover control for combination via tethered space robot

    Science.gov (United States)

    Lu, Yingbo; Huang, Panfeng; Meng, Zhongjie; Hu, Yongxin; Zhang, Fan; Zhang, Yizhai

    2017-07-01

    Up to April 6, 2016, there are 17,385 large debris in orbit around the Earth, which poses a serious hazard to near-Earth space activities. As a promising on-orbit debris capture strategy, tethered space robots (TSRs) have wide applications in future on-orbit service owing to its flexibility and great workspace. However, lots of problems may arise in the Tethered Space Robots (TSRs) system from the approaching, capturing, postcapturing and towing phases. The postcapture combination attitude takeover control by the TSR is studied in this paper. Taking control constraints, tether oscillations and external disturbances into consideration, a fast terminal sliding mode control (FTSMC) methodology with dual closed loops for the flexible combination attitude takeover control is designed. The unknown upper bounds of the uncertainties, external disturbances are estimated through adaptive techniques. Stability of the dual closed loop control system and finite time convergence of system states are proved via Lyapunov stability theory. Besides, null space intersection control allocation was adopted to distribute the required control moment over TSR's redundant thrusters. Simulation studies have been conducted to demonstrate the effectiveness of the proposed controller with the conventional sliding mode control(SMC).

  14. Attitude control for on-orbit servicing spacecraft using hybrid actuator

    Science.gov (United States)

    Wu, Yunhua; Han, Feng; Zheng, Mohong; He, Mengjie; Chen, Zhiming; Hua, Bing; Wang, Feng

    2018-03-01

    On-orbit servicing is one of the research hotspots of space missions. A small satellite equipped with multiple robotic manipulators is expected to carry out device replacement task for target large spacecraft. Attitude hyperstable control of a small satellite platform under rotations of the manipulators is a challenging problem. A hybrid momentum exchanging actuator consists of Control Moment Gyro (CMG) and Reaction Wheel (RW) is proposed to tackle the above issue, due to its huge amount of momentum storage capacity of the CMG and high control accuracy of the RW, in which the CMG produces large command torque while the RW offers additional control degrees. The constructed dynamic model of the servicing satellite advises that it's feasible for attitude hyperstable control of the platform with arbitrary manipulators through compensating the disturbance generated by rapid rotation of the manipulators. Then, null motion between the CMG and RW is exploited to drive the system to the expected target with favorable performance, and to overcome the CMG inherent geometric singularity and RW saturation. Simulations with different initial situations, including CMG hyperbolic and elliptic singularities and RW saturation, are executed. Compared to the scenarios where the CMG or RW fails stabilizing the platform, large control torque, precise control effect and escape of singularity are guaranteed by the introduced hybrid actuator, CMGRW (CMGRW refers to the hybrid momentum exchanging devices in this paper, consisting of 4 CMGs in classical pyramid cluster and 3 RWs in an orthogonal group (specific description can been found in Section 4)). The feasible performance of the satellite, CMG and RW under large disturbance demonstrates that the control architecture proposed is capable of attitude control for on-orbit servicing satellite with multiple robotic manipulators.

  15. Deterministic errors in the Magellan orbit due to attitude control thruster activity

    Science.gov (United States)

    Engelhardt, Douglas B.; Mohan, Srinivas N.

    1989-01-01

    The pitch and yaw attitude control thrusters of the Magellan spacecraft generate uncoupled moments about the spacecraft center of mass, perturbing the spacecraft's orbit. A strategy to model these perturbing forces in the spacecraft equations of motion is presented. This strategy can model the thruster forces occurring in the nominal and contingency modes of attitude control operation. In the nominal mode, the thrusters fire only to balance the daily unloading of the momentum wheels. The contingency case will occur if a pitch or yaw axis momentum wheel fails, and the thrusters could fire up to 1200 times around the orbit to replace the failed wheel's momentum contribution. Deterministic errors are computed and shown to be under specified error requirements.

  16. The Impact of Personal Attitude, Subjective Norm, and Perceived Behavioural Control on Entrepreneurial Intentions of Women

    Directory of Open Access Journals (Sweden)

    M. Sait DINC

    2016-05-01

    Full Text Available In the last decade, female entrepreneurship has been identified as one of the most important unutilised sources of economic growth. Entrepreneurial intention of women has become a key element in establishing a new business. The factors influencing entrepreneurial intention of women, particularly in developing countries, have attracted curiosity lot of attention. The purpose of the study is to examine the relationship between demographic variables, personal attitude, subjective norm, perceived behavioural control, and entrepreneurial intentions of women in Federation of Bosnia and Herzegovina. A total of 216 questionnaires were collected from women in two big cities in Bosnia: Tuzla and Sarajevo. Relationships between the variables were evaluated using factor analysis, reliability, correlations, descriptive statistics, and regression. The findings show a positive and significant influence of personal attitude and perceived behavioural control on entrepreneurial intention.

  17. Modifying attitude and intention toward regular physical activity using protection motivation theory: a randomized controlled trial.

    Science.gov (United States)

    Mirkarimi, Kamal; Eri, Maryam; Ghanbari, Mohammad R; Kabir, Mohammad J; Raeisi, Mojtaba; Ozouni-Davaji, Rahman B; Aryaie, Mohammad; Charkazi, Abdurrahman

    2017-10-30

    We were guided by the Protection Motivation Theory to test the motivational interviewing effects on attitude and intention of obese and overweight women to do regular physical activity. In a randomized controlled trial, we selected using convenience sampling 60 overweight and obese women attending health centres. The women were allocated to 2 groups of 30 receiving a standard weight-control programme or motivational interviewing. All constructs of the theory (perceived susceptibility, severity, self-efficacy and response efficacy) and all anthropometric characteristics (except body mass index) were significantly different between the groups at 3 study times. The strongest predictors of intention to do regular physical exercise were perceived response efficacy and attitude at 2- and 6-months follow-up. We showed that targeting motivational interviewing with an emphasis on Protection Motivation Theory constructs appeared to be beneficial for designing and developing appropriate intervention to improve physical activity status among women with overweight and obesity.

  18. Linear Time Varying Approach to Satellite Attitude Control Using only Electromagnetic Actuation

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2000-01-01

    , lightweight, and power efficient actuators is therefore crucial and viable. This paper discusser linear attitude control strategies for a low earth orbit satellite actuated by a set of mutually perpendicular electromagnetic coils. The principle is to use the interaction between the Earth's magnetic field......, nevertheless, a solution of the riccati equation gives an excellent frame for investigations provided in this paper. An observation that geomagnetic field changes approximately periodically when satellite is on a near polar orbit is used throughout this paper. Three types of attitude controllers are proposed......Recently small satellite missions have gained considerable interest due to low-cost launch opportunities and technological improvemant of micro-electronics. Required pointing accuracy of small, inexpensive satellites is often relatively loose, within a couple of degrees. Application of cheap...

  19. Analysis of Pan-European attitudes to the eradication and control of bovine viral diarrhoea.

    Science.gov (United States)

    Heffernan, C; Misturelli, F; Nielsen, L; Gunn, G J; Yu, J

    2009-02-07

    At present, national-level policies concerning the eradication and control of bovine viral diarrhoea (BVD) differ widely across Europe. Some Scandinavian countries have enacted strong regulatory frameworks to eradicate the disease, whereas other countries have few formal policies. To examine these differences, the attitudes of stakeholders and policy makers in 17 European countries were investigated. A web-based questionnaire was sent to policy makers, government and private sector veterinarians, and representatives of farmers' organisations. In total, 131 individuals responded to the questionnaire and their responses were analysed by applying a method used in sociolinguistics: frame analysis. The results showed that the different attitudes of countries that applied compulsory or voluntary frameworks were associated with different views about the attribution or blame for BVD and the roles ascribed to farmers and other stakeholders in its eradication and control.

  20. 42: An Open-Source Simulation Tool for Study and Design of Spacecraft Attitude Control Systems

    Science.gov (United States)

    Stoneking, Eric

    2018-01-01

    Simulation is an important tool in the analysis and design of spacecraft attitude control systems. The speaker will discuss the simulation tool, called simply 42, that he has developed over the years to support his own work as an engineer in the Attitude Control Systems Engineering Branch at NASA Goddard Space Flight Center. 42 was intended from the outset to be high-fidelity and powerful, but also fast and easy to use. 42 is publicly available as open source since 2014. The speaker will describe some of 42's models and features, and discuss its applicability to studies ranging from early concept studies through the design cycle, integration, and operations. He will outline 42's architecture and share some thoughts on simulation development as a long-term project.

  1. Attitudes to Gun Control in an American Twin Sample: Sex Differences in the Causes of Variation.

    Science.gov (United States)

    Eaves, Lindon J; Silberg, Judy L

    2017-10-01

    The genetic and social causes of individual differences in attitudes to gun control are estimated in a sample of senior male and female twin pairs in the United States. Genetic and environmental parameters were estimated by weighted least squares applied to polychoric correlations for monozygotic (MZ) and dizygotic (DZ) twins of both sexes. The analysis suggests twin similarity for attitudes to gun control in men is entirely genetic while that in women is purely social. Although the volunteer sample is small, the analysis illustrates how the well-tested concepts and methods of genetic epidemiology may be a fertile resource for deepening our scientific understanding of biological and social pathways that affect individual risk to gun violence.

  2. Cassini Attitude Control Flight Software: from Development to In-Flight Operation

    Science.gov (United States)

    Brown, Jay

    2008-01-01

    The Cassini Attitude and Articulation Control Subsystem (AACS) Flight Software (FSW) has achieved its intended design goals by successfully guiding and controlling the Cassini-Huygens planetary mission to Saturn and its moons. This paper describes an overview of AACS FSW details from early design, development, implementation, and test to its fruition of operating and maintaining spacecraft control over an eleven year prime mission. Starting from phases of FSW development, topics expand to FSW development methodology, achievements utilizing in-flight autonomy, and summarize lessons learned during flight operations which can be useful to FSW in current and future spacecraft missions.

  3. Indirect Adaptive Attitude Control for a Ducted Fan Vertical Takeoff and Landing Microaerial Vehicle

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-01-01

    Full Text Available The present paper addresses an attitude tracking control problem of a ducted fan microaerial vehicle. The proposed indirect adaptive controller can greatly reduce tracking error in the initial stage of the adaptive learning process by using an error compensation strategy and can achieve good capability to eliminate the adverse effect of measurement noises on the convergence of adjustable parameters. Moreover, the learning rate adaptation strategy is proposed to further minimize the adverse effect of large learning rates on the convergence of adjustable parameters. The experimental tests have illustrated the effectiveness of the proposed adaptive controller.

  4. Predicting healthcare employees' participation in an office redesign program: Attitudes, norms and behavioral control

    Directory of Open Access Journals (Sweden)

    Lukas Carol

    2008-11-01

    Full Text Available Abstract Background The study examined the extent to which components based on a modified version of the theory of planned behavior explained employee participation in a new clinical office program designed to reduce patient waiting times in primary care clinics. Methods We regressed extent of employee participation on attitudes about the program, group norms, and perceived behavioral control along with individual and clinic characteristics using a hierarchical linear mixed model. Results Perceived group norms were one of the best predictors of employee participation. Attitudes about the program were also significant, but to a lesser degree. Behavioral control, however, was not a significant predictor. Respondents with at least one year of clinic tenure, or who were team leaders, first line supervisor, or managers had greater participation rates. Analysis at the clinic level indicated clinics with scores in the highest quartile clinic scores on group norms, attitudes, and behavioral control scores were significantly higher on levels of overall participation than clinics in the lowest quartile. Conclusion Findings suggest that establishing strong norms and values may influence employee participation in a change program in a group setting. Supervisory level was also significant with greater responsibility being associated with greater participation.

  5. Attitudes of women from five European countries regarding tobacco control policies.

    Science.gov (United States)

    Dresler, Carolyn; Wei, Mei; Heck, Julia E; Allwright, Shane; Haglund, Margaretha; Sanchez, Sara; Kralikova, Eva; Stücker, Isabelle; Tamang, Elizabeth; Gritz, Ellen R; Hashibe, Mia

    2013-03-01

    Tobacco-related cancers and, in particular, lung cancer still represents a substantial public health epidemic across Europe as a result of high rates of smoking prevalence. Countries in Europe have proposed and implemented tobacco control policies to reduce smoking prevalence, with some countries being more progressive than others. The aim of this study was to examine factors that influenced women's attitudes across five European countries relative to comprehensive smokefree laws in their countries. A cross-sectional landline telephone survey on attitudes towards tobacco control laws was conducted in five European countries: France, Ireland, Italy, the Czech Republic, and Sweden. Attitudinal scores were determined for each respondent relative to questions about smokefree laws. Logistic regression models were used to obtain odds ratios with 95% confidence intervals. A total of 5000 women were interviewed (1000 women from each country). The majority of women, regardless of smoking history, objected to smoking in public buses, enclosed shopping centers, hospitals, and other indoor work places. More women who had quit smoking believed that new tobacco control laws would prompt cessation - as compared with women who still smoked. In general, there is very high support for national smokefree laws that cover bars, restaurants, and public transport systems. As such laws are implemented, attitudes do change, as demonstrated by the differences between countries such as Ireland and the Czech Republic. Implementing comprehensive smokefree laws will gain high approval and will be associated with prompting people to quit.

  6. A Simple Attitude Control of Quadrotor Helicopter Based on Ziegler-Nichols Rules for Tuning PD Parameters

    Directory of Open Access Journals (Sweden)

    ZeFang He

    2014-01-01

    Full Text Available 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.

  7. Nurses' Perceptions and Attitudes Toward Use of Oral Patient-Controlled Analgesia.

    Science.gov (United States)

    Riemondy, Susan; Gonzalez, Lorie; Gosik, Kirk; Ricords, Amy; Schirm, Victoria

    2016-04-01

    Patient-controlled analgesia (PCA) administered intravenously is a generally well-accepted therapy by nurses and patients. PCA devices are now available for oral medications, allowing patients to self-administer pain pills without requesting them from the nurse. Successful introduction of new pain medication delivery devices can depend on nurses' knowledge and attitudes. The aim of this institutional review board approved project was to evaluate nurses' perceptions and attitudes toward using an oral PCA device for patients' pain. A 4-week study was designed and conducted at an academic medical center on an orthopedic unit and a women's health unit. Nurse participants received education on using the oral PCA device and were invited to complete a pre- and poststudy knowledge and attitude survey regarding pain management. Nurses and patients also completed a questionnaire about perceptions related to using the oral PCA device. Findings showed that nurses' attitudes toward using the oral PCA device were less favorable than those of patients, suggesting that nurses may require additional education for acceptance of this device. Results from 37 nurses showed improvement in overall knowledge and attitudes, from 70.8% pretest to 74.2% post-test. Although improvement was not statistically significant (p = .1637), two items showed significant improvement. Knowledge about the effectiveness of NSAIDS was 27.5% pretest compared with 60.0% post-test (p = .0028); and understanding about use of opioids in patients with a history of substance abuse was 50% pretest compared with 70% post-test (p = .0531). Helping nurses overcome the perceived barriers to use of an oral PCA device has potential implications for better pain management as well as enhanced patient satisfaction. Copyright © 2016 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  8. Knowledge, attitude, and practice of urban Gujarati type 2 diabetics: Prevalence and impact on disease control.

    Science.gov (United States)

    Solanki, Jayesh Dalpatbhai; Sheth, Nidhi Shaileshbhai; Shah, Chinmay J; Mehta, Hemant B

    2017-01-01

    Type 2 diabetes is the modern epidemic wherein patient care needs multiple approaches, education, and self-awareness being one of them. There are some knowledge, attitude, and practice (KAP) studies from India but very few relating it with disease control. We tried to study KAP of treated type 2 diabetics and its correlation with glycemic control. Cross-sectional KAP study. We formulated KAP questionnaires in the form of KAP - 10 points for each and total 30. We recruited 200 type 2 diabetics (96 males, 104 females) treated by MD physicians with known current glycemic status. They were asked KAP questionnaires one to one by a direct interview in local language and results were associated with various factors and glycemic control. KAP score on was average 19 out of 30 in type 2 diabetics having mean age 58 years, mean duration 9 years. KAP score was unaffected by gender, occupation, duration of disease but significantly affected by current age, and education level. Only 40% patients had good glycemic control who scored better KAP than poor glycemic. There was positive correlation between KAP score and glycemic control, with significance for only glycosylated hemoglobin and not fasting blood sugar, postprandial blood sugar. Physician treated type 2 diabetics of our region had moderate KAP score, affected by age, education which suggested to affect glycemic control. Lacunae in knowledge regarding incurability of disease, attitudes toward complication, self-care, and good practices like walking, enriching knowledge need improvement so as an optimum glycemic control.

  9. Fault Detection and Correction for the Solar Dynamics Observatory Attitude Control System

    Science.gov (United States)

    Starin, Scott R.; Vess, Melissa F.; Kenney, Thomas M.; Maldonado, Manuel D.; Morgenstern, Wendy M.

    2007-01-01

    The Solar Dynamics Observatory is an Explorer-class mission that will launch in early 2009. The spacecraft will operate in a geosynchronous orbit, sending data 24 hours a day to a devoted ground station in White Sands, New Mexico. It will carry a suite of instruments designed to observe the Sun in multiple wavelengths at unprecedented resolution. The Atmospheric Imaging Assembly includes four telescopes with focal plane CCDs that can image the full solar disk in four different visible wavelengths. The Extreme-ultraviolet Variability Experiment will collect time-correlated data on the activity of the Sun's corona. The Helioseismic and Magnetic Imager will enable study of pressure waves moving through the body of the Sun. The attitude control system on Solar Dynamics Observatory is responsible for four main phases of activity. The physical safety of the spacecraft after separation must be guaranteed. Fine attitude determination and control must be sufficient for instrument calibration maneuvers. The mission science mode requires 2-arcsecond control according to error signals provided by guide telescopes on the Atmospheric Imaging Assembly, one of the three instruments to be carried. Lastly, accurate execution of linear and angular momentum changes to the spacecraft must be provided for momentum management and orbit maintenance. In thsp aper, single-fault tolerant fault detection and correction of the Solar Dynamics Observatory attitude control system is described. The attitude control hardware suite for the mission is catalogued, with special attention to redundancy at the hardware level. Four reaction wheels are used where any three are satisfactory. Four pairs of redundant thrusters are employed for orbit change maneuvers and momentum management. Three two-axis gyroscopes provide full redundancy for rate sensing. A digital Sun sensor and two autonomous star trackers provide two-out-of-three redundancy for fine attitude determination. The use of software to maximize

  10. A neural network approach to fault detection in spacecraft attitude determination and control systems

    Science.gov (United States)

    Schreiner, John N.

    This thesis proposes a method of performing fault detection and isolation in spacecraft attitude determination and control systems. The proposed method works by deploying a trained neural network to analyze a set of residuals that are defined such that they encompass the attitude control, guidance, and attitude determination subsystems. Eight neural networks were trained using either the resilient backpropagation, Levenberg-Marquardt, or Levenberg-Marquardt with Bayesian regularization training algorithms. The results of each of the neural networks were analyzed to determine the accuracy of the networks with respect to isolating the faulty component or faulty subsystem within the ADCS. The performance of the proposed neural network-based fault detection and isolation method was compared and contrasted with other ADCS FDI methods. The results obtained via simulation showed that the best neural networks employing this method successfully detected the presence of a fault 79% of the time. The faulty subsystem was successfully isolated 75% of the time and the faulty components within the faulty subsystem were isolated 37% of the time.

  11. Attitudes toward Placebo-Controlled Clinical Trials of Patients with Schizophrenia in Japan.

    Directory of Open Access Journals (Sweden)

    Norio Sugawara

    Full Text Available Although the use of placebo in clinical trials of schizophrenia patients is controversial because of medical and ethical concerns, placebo-controlled clinical trials are commonly used in the licensing of new drugs.The objective of this study was to assess the attitudes toward placebo-controlled clinical trials among patients with schizophrenia in Japan.Using a cross-sectional design, we recruited patients (n = 251 aged 47.7±13.2 (mean±SD with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who were admitted to six psychiatric hospitals from December 2013 to March 2014. We employed a 14-item questionnaire specifically developed to survey patients' attitudes toward placebo-controlled clinical trials.The results indicated that 33% of the patients would be willing to participate in a placebo-controlled clinical trial. Expectations for improvement of disease, a guarantee of hospital treatment continuation, and encouragement by family or friends were associated with the willingness to participate in such trials, whereas a belief of additional time required for medical examinations was associated with non-participation.Fewer than half of the respondents stated that they would be willing to participate in placebo-controlled clinical trials. Therefore, interpreting the results from placebo-controlled clinical trials could be negatively affected by selection bias.

  12. Thrust distribution for attitude control in a variable thrust propulsion system with four ACS nozzles

    Science.gov (United States)

    Lim, Yeerang; Lee, Wonsuk; Bang, Hyochoong; Lee, Hosung

    2017-04-01

    A thrust distribution approach is proposed in this paper for a variable thrust solid propulsion system with an attitude control system (ACS) that uses a reduced number of nozzles for a three-axis attitude maneuver. Although a conventional variable thrust solid propulsion system needs six ACS nozzles, this paper proposes a thrust system with four ACS nozzles to reduce the complexity and mass of the system. The performance of the new system was analyzed with numerical simulations, and the results show that the performance of the system with four ACS nozzles was similar to the original system while the mass of the whole system was simultaneously reduced. Moreover, a feasibility analysis was performed to determine whether a thrust system with three ACS nozzles is possible.

  13. A method of testing attitude control systems during the development phase

    Science.gov (United States)

    Besonis, A.; Dougherty, H.; Levinthal, J.; Meadows, P.

    1981-01-01

    A technique, utilized on the Space Telescope Program, and used for testing satellite attitude pointing and control systems during the engineering and development phases is presented. The technique verifies the hardware models used in design phase computer simulations, verifies the interface between the flight hardware and flight software, and uncovers hardware/software switching or mode logic problems. The testing is accomplished in two phases: a dynamic hardware simulator phase using hardware electronic simulators and an electronic vehicle motion simulator; and a second real hardware phase utilizing engineering model gyros and reaction wheels on an airbearing table. Both phases use an engineering model of the flight computer, flight algorithms and software, and a breadboard data management and computer hardware interface for timing simulations. The purpose of each test and the test phases are described, and examples of closed loop test results for both attitude hold and maneuvering models are given.

  14. Linear Time Varying Approach to Satellite Attitude Control Using only Electromagnetic Actuation

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    1997-01-01

    , lightweight, and power efficient actuators is therefore crucial and viable. This paper discusses linear attitude control strategies for a low earth orbit satellite actuated by a set of mutually perpendicular electromagnetic coils. The principle is to use the interaction between the Earth's magnetic field...... systems is limited, nevertheless, a solution of the Riccati equation gives an excellent frame for investigations provided in this paper. An observation that geomagnetic field changes approximately periodically when a satellite is on a near polar orbit is used throughout this paper. Three types of attitude......Recently small satellite missions have gained considerable interest due to low-cost launch opportunities and technological improvement of micro-electronics. Required pointing accuracy of small, inexpensive satellites is often relatively loose, within a couple of degrees. Application of cheap...

  15. Balloon infrared astronomy platform (BIRAP). [development and characteristics of a balloon-borne attitude control system

    Science.gov (United States)

    Greeb, M. E.; True, G. A.

    1974-01-01

    The development of a balloon-borne attitude control system for infrared astronomy studies is discussed. The Balloon Infrared Astronomy Platform (BIRAP) is the result of the development effort. The BIRAP uses electronic gimballing for the offset pointing which eliminates a set of mechanical gimbals. Guide stars with visual magnitudes as low as plus 6 are used for fine tracking assuring that all areas of the sky can be covered. The BIRAP control concept uses a closed loop system in the airborne equipment with automatic update through a command link that can be operated either manually or automatically by a ground based computer.

  16. Motion coordination for VTOL unmanned aerial vehicles attitude synchronisation and formation control

    CERN Document Server

    Abdessameud, Abdelkader

    2013-01-01

    Motion Coordination for VTOL Unmanned Aerial Vehicles develops new control design techniques for the distributed coordination of a team of autonomous unmanned aerial vehicles. In particular, it provides new control design approaches for the attitude synchronization of a formation of rigid body systems. In addition, by integrating new control design techniques with some concepts from nonlinear control theory and multi-agent systems, it presents  a new theoretical framework for the formation control of a class of under-actuated aerial vehicles capable of vertical take-off and landing. Several practical problems related to the systems’ inputs, states measurements, and  restrictions on the interconnection  topology  between the aerial vehicles in the team  are addressed. Worked examples with sufficient details and simulation results are provided to illustrate the applicability and effectiveness of the theoretical results discussed in the book. The material presented is primarily intended for researchers an...

  17. Attitude stabilization of flexible spacecrafts via extended disturbance observer based controller

    Science.gov (United States)

    Yan, Ruidong; Wu, Zhong

    2017-04-01

    To achieve the high-precision attitude stabilization for the flexible spacecraft in the presence of space environmental disturbances, unmodeled dynamics, and the disturbances caused by the elastic vibration of flexible appendages, an extended disturbance observer (EDO) based controller is proposed. The proposed controller is formulated by combining EDO and a backstepping feedback controller. EDO is used to estimate the disturbance, which is modeled as an unknown high-order differentiable equation and the rth-order derivative of the disturbance is assumed to be bounded. Compared to the conventional first-order disturbance observer, the higher order EDO offers improvement in estimate accuracy, if the absolute values of poles for EDO transfer function are chosen larger than the frequency content of the disturbance. Then, the output of EDO plus the backstepping feedback controller are applied to stabilize the attitude with high precision by rejecting disturbances for the flexible spacecraft. Finally, numerical simulations have been conducted to verify the effectiveness of the proposed controller.

  18. Nurse Attitude-Related Barriers to Effective Control of Cancer Pain among Iranian Nurses.

    Science.gov (United States)

    Name, Name; Mohamadian, Robab; Rahmani, Azad; Fizollah-Zadeh, Hussein; Jabarzadeh, Franak; Azadi, Arman; Rostami, Hussein

    2016-01-01

    Many cancer patients still experience pain worldwide. There are many barriers for effective control of cancer pain and many of these are related to health care providers. There is a need for further investigation of these barriers. The aim of this study was to investigate nurse-related barriers to control of cancer pain among Iranian nurses. In this descriptive study 49 nurses from two hospitals affiliated to Tabriz and Ardebil Universities of Medical Sciences participated using a census sampling method. A demographic and profession related checklist and Barriers Questionnaire II (BQ-II) were used for data collection. The results showed negative attitudes of participants regarding control of cancer pain. Participants believed that cancer pain medications do not manage cancer pain at acceptable levels; patients may become addicted by using these drugs; cancer pain medications have many uncontrollable effects; and controlling cancer pain may distract the physicians from treating disease. Iranian nurses have negative attitudes toward pain control in cancer patients especially about effectiveness of pain medication and their side effects. Educational intervention to reduce these misconceptions is needed.

  19. Improving psychology students' attitudes toward people with schizophrenia: A quasi-randomized controlled study.

    Science.gov (United States)

    Magliano, Lorenza; Rinaldi, Angela; Costanzo, Regina; De Leo, Renata; Schioppa, Giustina; Petrillo, Miriam; Read, John

    2016-01-01

    Despite scientific evidence that the majority of people with schizophrenia (PWS) have personal histories of traumatic life events and adversities, their needs for psychological support often remain unmet. Poor availability of nonpharmacological therapies in schizophrenia may be partly because of professionals' attitudes toward people diagnosed with this disorder. As future health professionals, psychology students represent a target population for efforts to increase the probability that PWS will be offered effective psychological therapies. This quasi-randomized controlled study investigated the effect of an educational intervention, addressing common prejudices via scientific evidence and prerecorded audio-testimony from PWS, on the attitudes of psychology students toward PWS. Students in their fifth year of a master's degree in Psychology at the Second University of Naples, Italy were randomly assigned to an experimental group-which attended two 3-hr sessions a week apart-or to a control group. Compared with their baseline assessment, at 1-month reassessment the 76 educated students endorsed more psychosocial causes and more of them recommended psychologists in the treatment of schizophrenia. They were also more optimistic about recovery, less convinced that PWS are recognizable and unpredictable, and more convinced that treatments, pharmacological and psychological, are useful. No significant changes were found, from baseline to 1-month reassessment, in the 112 controls. At 1-month reassessment, educated students were more optimistic about recovery and less convinced that PWS are unpredictable than controls. These findings suggest that psychology students' attitudes toward PWS can be improved by training initiatives including education and indirect contact with users. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  20. Relationships between objective physical characteristics and the use of weight control methods in adolescence: a mediating role for eating attitudes?

    Science.gov (United States)

    Peñas Lledó, E; Sancho, L; Waller, G

    2001-09-01

    This study of non-clinical adolescent males and females examined associations of objectively measured physical characteristics with greater use of methods of weight control and considered whether the relationships between these variables might be explained by a mediating effect of a subjective characteristic--unhealthy eating attitudes. Non-clinical male and female adolescents completed measures of weight control and eating attitudes, and their physical characteristics were measured using a range of standardized anthropometry techniques. Regression analyses were used to test the role of eating attitudes as mediators in the relationship between physical characteristics and the use of weight control methods. The data were compatible with a partial mediator model, where physical characteristics influence eating attitudes, and those where attitudes drive the use of methods to control weight. However, not all of the relationship was explained by this mediator. In addition, there were different patterns of association for men and women, consistent with different patterns of bodily focus between the genders. These findings stress the importance of understanding objective physical characteristics as well as subjective eating attitudes to find out why people use different levels of weight control behaviours. Limitations, further research and potential implications for clinical and preventative programmes are discussed.

  1. Controlling healthcare professionals: how human resource management influences job attitudes and operational efficiency.

    Science.gov (United States)

    Cogin, Julie Ann; Ng, Ju Li; Lee, Ilro

    2016-09-20

    We assess how human resource management (HRM) is implemented in Australian hospitals. Drawing on role theory, we consider the influence HRM has on job attitudes of healthcare staff and hospital operational efficiency. We adopt a qualitative research design across professional groups (physicians, nurses, and allied health staff) at multiple levels (executive, healthcare managers, and employee). A total of 34 interviews were carried out and analyzed using NVivo. Findings revealed a predominance of a control-based approach to people management. Using Snell's control framework (AMJ 35:292-327, 1992), we found that behavioral control was the principal form of control used to manage nurses, allied health workers, and junior doctors. We found a mix between behavior, output, and input controls as well as elements of commitment-based HRM to manage senior physicians. We observed low levels of investment in people and a concentration on transactional human resource (HR) activities which led to negative job attitudes such as low morale and frustration among healthcare professionals. While hospitals used rules to promote conformity with established procedures, the overuse and at times inappropriate use of behavior controls restricted healthcare managers' ability to motivate and engage their staff. Excessive use of behavior control helped to realize short-term cost-cutting goals; however, this often led to operational inefficiencies. We suggest that hospitals reduce the profusion of behavior control and increase levels of input and output controls in the management of people. Poor perceptions of HR specialists and HR activities have resulted in HR being overlooked as a vehicle to address the strategic challenges required of health reform and to build an engaged workforce.

  2. Robust Optimal Attitude Controller for MIMO Uncertain Hexarotor MAVs: Disturbance Observer-Based

    Directory of Open Access Journals (Sweden)

    Nurul Dayana Salim

    2016-01-01

    Full Text Available This paper proposes a robust optimal attitude control design for multiple-input, multiple-output (MIMO uncertain hexarotor micro aerial vehicles (MAVs in the presence of parametric uncertainties, external time-varying disturbances, nonlinear dynamics, and coupling. The parametric uncertainties, external time-varying disturbances, nonlinear dynamics, and coupling are treated as the total disturbance in the proposed design. The proposed controller is achieved in two simple steps. First, an optimal linear-quadratic regulator (LQR controller is designed to guarantee that the nominal closed-loop system is asymptotically stable without considering the total disturbance. After that, a disturbance observer is integrated into the closed-loop system to estimate the total disturbance acting on the system. The total disturbance is compensated by a compensation input based on the estimated total disturbance. Robust properties analysis is given to prove that the state is ultimately bounded in specified boundaries. Simulation results illustrate the robustness of the disturbance observer-based optimal attitude control design for hovering and aggressive flight missions in the presence of the total disturbance.

  3. Imaging X-Ray Polarimetry Explorer Mission Attitude Determination and Control Concept

    Science.gov (United States)

    Bladt, Jeff; Deininger, William D.; Kalinowski, William C.; Boysen, Mary; Bygott, Kyle; Guy, Larry; Pentz, Christina; Seckar, Chris; Valdez, John; Wedmore, Jeffrey; hide

    2018-01-01

    The goal of the Imaging X-Ray Polarimetry Explorer (IXPE) Mission is to expand understanding of high-energy astrophysical processes and sources, in support of NASA's first science objective in Astrophysics: "Discover how the universe works." X-ray polarimetry is the focus of the IXPE science mission. Polarimetry uniquely probes physical anisotropies-ordered magnetic fields, aspheric matter distributions, or general relativistic coupling to black-hole spin-that are not otherwise measurable. The IXPE Observatory consists of Spacecraft and Payload modules. The Payload includes three polarization sensitive, X-ray detector units (DU), each paired with its corresponding grazing incidence mirror module assemblies (MMA). A deployable boom provides the correct separation (focal length) between the DUs and MMAs. These Payload elements are supported by the IXPE Spacecraft. A star tracker is mounted directly with the deployed Payload to minimize alignment errors between the star tracker line of sight (LoS) and Payload LoS. Stringent pointing requirements coupled with a flexible structure and a non-collocated attitude sensor-actuator configuration requires a thorough analysis of control-structure interactions. A non-minimum phase notch filter supports robust control loop stability margins. This paper summarizes the IXPE mission science objectives and Observatory concepts, and then it describes IXPE attitude determination and control implementation. IXPE LoS pointing accuracy, control loop stability, and angular momentum management are discussed.

  4. The effects of educating mothers and girls on the girls' attitudes toward puberty health: a randomized controlled trial.

    Science.gov (United States)

    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.

  5. Evaluation and modeling of autonomous attitude thrust control for the Geostation Operational Environmental Satellite (GOES)-8 orbit determination

    Science.gov (United States)

    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.

  6. Attitude guidance and control of the navigation satellites at passage of singular orbit sites

    Science.gov (United States)

    Fateev, Alexey; Vassilyev, Alexander; Somov, Sergey

    2017-01-01

    The solar-terrestrial reference frame is applied during a navigation satellite flight using onboard measured units of directions on the Sun and Earth, which are beginning in the satellite (Object) mass center. The angle between these units traditionally is named as the angle SOE (Sun - Object - Earth). We consider problems of attitude guidance and control at the spacecraft operation on specific parts of the orbit (singular orbit sites) at following values of the SOE angles — close to 0 deg (small SOE angles) and close to 180 deg (large SOE angles) with a view to minimizing the impact of solar pressure forces on the SC mass center motion.

  7. Electric propulsion. [pulsed plasma thruster and electron bombardment ion engine for MSAT attitude control and stationkeeping

    Science.gov (United States)

    1982-01-01

    An alternative propulsion subsystem for MSAT is presented which has a potential of reducing the satellite weight by more than 15%. The characteristics of pulsed plasma and ion engines are described and used to estimate of the mass of the propellant and thrusters for attitude control and stationkeeping functions for MSAT. Preliminary estimates indicate that the electric propulsion systems could also replace the large momentum wheels necessary to counteract the solar pressure; however, the fine pointing wheels would be retained. Estimates also show that either electric propulsion system can save approximately 18% to 20% of the initial 4,000 kg mass. The issues that require further experimentation are mentioned.

  8. Improved ITOS attitude control system with Hall generator brushless motor and earth-splitting technique

    Science.gov (United States)

    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.

  9. Attitude control and sloshing suppression for liquid-filled spacecraft in the presence of sinusoidal disturbance

    Science.gov (United States)

    Zhang, Honghua; Wang, Zeguo

    2016-11-01

    The attitude regulation for a liquid-filled spacecraft in the presence of low frequency sinusoidal disturbance is considered in this paper. The liquid-filled spacecraft is modelled as a rigid body attached with a simple pendulum. A novel control scheme is proposed, which is composed of Active Disturbance Rejection Control (ADRC), Positive Position Feedback (PPF), Extended State Observer (ESO) and Singular Spectrum Analysis (SSA). The unknown sloshing mode could be estimated from the combined ESO and SSA, and accordingly ADRC and PPF controller is designed for the stabilization of the spacecraft. Particularly, the parameters of the disturbance are not required as long as its frequency is lower than the sloshing one. The proposed approach could provide stabilization for the spacecraft, rejection for the disturbance, and active damping for the sloshing. Its effectiveness is validated by numerical simulations.

  10. The Effects of Cueing and Framing on Youth Attitudes towards Gun Control and Gun Rights

    Directory of Open Access Journals (Sweden)

    Stephen Wu

    2018-02-01

    Full Text Available I analyze attitudes towards gun control from a recent survey of American high school students. For students who most closely identify as Republicans, cueing them to think about prior school shootings increases their agreement that armed staff in schools will improve safety and arming citizens will reduce risk of mass shootings. For those identifying as Democrats and Independents, providing them with selective information that certain states have loose gun control laws and low rates of gun violence makes them more supportive of gun rights. For Republicans, providing selective information that certain states have loose gun control laws and high rates of gun violence makes them less supportive of gun rights. These results suggest that emotional cues may exacerbate a priori biases, while informational cues may be more likely to change people’s minds about firearm policies.

  11. Eating on impulse: Implicit attitudes, self-regulatory resources, and trait self-control as determinants of food consumption.

    Science.gov (United States)

    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.

  12. Design, dynamics and control of an Adaptive Singularity-Free Control Moment Gyroscope actuator for microspacecraft Attitude Determination and Control System

    Science.gov (United States)

    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

  13. Methods of fertility control in cats: Owner, breeder and veterinarian behavior and attitudes.

    Science.gov (United States)

    Murray, Jane K; Mosteller, Jill R; Loberg, Jenny M; Andersson, Maria; Benka, Valerie A W

    2015-09-01

    Fertility control is important for population management of owned and unowned cats, provides health benefits at the individual level and can reduce unwanted sexually dimorphic behaviors such as roaming, aggression, spraying and calling. This article reviews the available evidence regarding European and American veterinarian, owner and pedigree cat breeder attitudes toward both surgical sterilization and non-surgical fertility control. It additionally presents new data on veterinarians' and pedigree cat breeders' use of, and attitudes toward, alternative modalities of fertility control. Within the United States and Europe, the proportion of cats reported to be sterilized varies widely. Published estimates range from 27-93% for owned cats and 2-5% for cats trapped as part of a trap-neuter-return (TNR) program. In some regions and populations of cats, non-surgical fertility control is also used. Social context, cultural norms, individual preferences, economic considerations, legislation and professional organizations may all influence fertility control decisions for cats. Particularly in Europe, a limited number of non-surgical temporary contraceptives are available for cats; these include products with regulatory approval for cats as well as some used 'off label'. Non-surgical methods remove the risk of complications related to surgery and offer potential to treat more animals in less time and at lower cost; they may also appeal to pedigree cat breeders seeking temporary contraception. However, concerns over efficacy, delivery methods, target species safety, duration and side effects exist with current non-surgical options. Research is under way to develop new methods to control fertility in cats without surgery. US and European veterinarians place high value on three perceived benefits of surgical sterilization: permanence, behavioral benefits and health benefits. Non-surgical options will likely need to share these benefits to be widely accepted by the veterinary

  14. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    Science.gov (United States)

    O’Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    Objective Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. Method The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification) were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. Results After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58) was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46), which likely represents self-interest in retaining property (guns). Conclusions Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites’ paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions. PMID:24204867

  15. Racism, gun ownership and gun control: biased attitudes in US whites may influence policy decisions.

    Science.gov (United States)

    O'Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification) were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58) was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46), which likely represents self-interest in retaining property (guns). Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites' paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions.

  16. Racism, gun ownership and gun control: biased attitudes in US whites may influence policy decisions.

    Directory of Open Access Journals (Sweden)

    Kerry O'Brien

    Full Text Available OBJECTIVE: Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty. This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. METHOD: The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites. Explanatory variables known to be related to gun ownership and gun control opposition (i.e., age, gender, education, income, conservatism, anti-government sentiment, southern vs. other states, political identification were entered in logistic regression models, along with measures of racism, and the stereotype of blacks as violent. Outcome variables included; having a gun in the home, opposition to bans on handguns in the home, support for permits to carry concealed handguns. RESULTS: After accounting for all explanatory variables, logistic regressions found that for each 1 point increase in symbolic racism there was a 50% increase in the odds of having a gun at home. After also accounting for having a gun in the home, there was still a 28% increase in support for permits to carry concealed handguns, for each one point increase in symbolic racism. The relationship between symbolic racism and opposition to banning handguns in the home (OR1.27 CI 1.03,1.58 was reduced to non-significant after accounting for having a gun in the home (OR1.17 CI.94,1.46, which likely represents self-interest in retaining property (guns. CONCLUSIONS: Symbolic racism was related to having a gun in the home and opposition to gun control policies in US whites. The findings help explain US whites' paradoxical attitudes towards gun ownership and gun control. Such attitudes may adversely influence US gun control policy debates and decisions.

  17. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data

    Science.gov (United States)

    Krening, Samantha C.

    2013-01-01

    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  18. Fault tolerant attitude control for small unmanned aircraft systems equipped with an airflow sensor array.

    Science.gov (United States)

    Shen, H; Xu, Y; Dickinson, B T

    2014-11-18

    Inspired by sensing strategies observed in birds and bats, a new attitude control concept of directly using real-time pressure and shear stresses has recently been studied. It was shown that with an array of onboard airflow sensors, small unmanned aircraft systems can promptly respond to airflow changes and improve flight performances. In this paper, a mapping function is proposed to compute aerodynamic moments from the real-time pressure and shear data in a practical and computationally tractable formulation. Since many microscale airflow sensors are embedded on the small unmanned aircraft system surface, it is highly possible that certain sensors may fail. Here, an adaptive control system is developed that is robust to sensor failure as well as other numerical mismatches in calculating real-time aerodynamic moments. The advantages of the proposed method are shown in the following simulation cases: (i) feedback pressure and wall shear data from a distributed array of 45 airflow sensors; (ii) 50% failure of the symmetrically distributed airflow sensor array; and (iii) failure of all the airflow sensors on one wing. It is shown that even if 50% of the airflow sensors have failures, the aircraft is still stable and able to track the attitude commands.

  19. A survey of cross-infection control procedures: knowledge and attitudes of Turkish dentists

    Directory of Open Access Journals (Sweden)

    Emir Yüzbasioglu

    2009-12-01

    Full Text Available OBJECTIVES: The objective of this study was to investigate the knowledge, attitudes and behavior of Turkish dentists in Samsun City regarding cross-infection control. MATERIAL AND METHODS: A questionnaire was designed to obtain information about procedures used for the prevention of cross-infection in dental practices and determine the attitudes and perceptions of respondent dental practitioners to their procedures. The study population included all dentists in the city of Samsun, Turkey, in April 2005 (n=184. The questionnaire collected data on sociodemographic characteristics, knowledge and practice of infection control procedures, sterilization, wearing of gloves, mask, use of rubber dam, method of storing instruments and disposal methods of contaminated material, etc. Questionnaire data was entered into a computer and analyzed by SPSS statistical software. RESULTS: From the 184 dentists to whom the questionnaires were submitted, 135 participated in the study (overall response rate of 73.36%. As much as 74.10% dentists expressed concern about the risk of cross-infection from patients to themselves and their dental assistants. Forty-three percent of the participants were able to define "cross-infection" correctly. The greatest majority of the respondents (95.60% stated that all patients have to be considered as infectious and universal precautions must apply to all of them. The overall responses to the questionnaire showed that the dentists had moderate knowledge of infection control procedures. CONCLUSIONS: Improved compliance with recommended infection control procedures is required for all dentists evaluated in the present survey. Continuing education programs and short-time courses about cross-infection and infection control procedures are suitable to improve the knowledge of dentists.

  20. Infection control knowledge, attitudes, and practices among healthcare workers in Addis Ababa, Ethiopia.

    Science.gov (United States)

    Tenna, Admasu; Stenehjem, Edward A; Margoles, Lindsay; Kacha, Ermias; Blumberg, Henry M; Kempker, Russell R

    2013-12-01

    To better understand hospital infection control practices in Ethiopia. A cross-sectional evaluation of healthcare worker (HCW) knowledge, attitudes, and practices about hand hygiene and tuberculosis (TB) infection control measures. An anonymous 76-item questionnaire was administered to HCWs at 2 university hospitals in Addis Ababa, Ethiopia. Knowledge items were scored as correct/incorrect. Attitude and practice items were assessed using a Likert scale. In total, 261 surveys were completed by physicians (51%) and nurses (49%). Fifty-one percent of respondents were male; mean age was 30 years. While hand hygiene knowledge was fair, self-reported practice was suboptimal. Physicians reported performing hand hygiene 7% and 48% before and after patient contact, respectively. Barriers for performing hand hygiene included lack of hand hygiene agents (77%), sinks (30%), and proper training (50%) as well as irritation and dryness (67%) caused by hand sanitizer made in accordance with the World Health Organization formulation. TB infection control knowledge was excellent (more than 90% correct). Most HCWs felt that they were at high risk for occupational acquisition of TB (71%) and that proper TB infection control can prevent nosocomial transmission (92%). Only 12% of HCWs regularly wore a mask when caring for TB patients. Only 8% of HCWs reported that masks were regularly available, and 76% cited a lack of infrastructure to isolate suspected/known TB patients. Training HCWs about the importance and proper practice of hand hygiene along with improving hand sanitizer options may improve patient safety. Additionally, enhanced infrastructure is needed to improve TB infection control practices and allay HCW concerns about acquiring TB in the hospital.

  1. Factors associated with Hispanic teenagers' attitude toward the importance of birth control.

    Science.gov (United States)

    Gibson, J W; Lanz, J B

    1991-10-01

    Attitudes of 240 female Hispanic teenagers in 1984-85 in New York City toward the importance of birth control (ATIBC) are examined as a reflection of the following: demographic factors, educational aspirations, maternal characteristics, religiosity, clarity of longterm goals, and perception of friends' behavior, i.e., the degree, formation, and variation of these factors. The nonrandom sample was recruited from pregnancy prevention classes. The questionnaire was available in English or Spanish. 9 research questions were of interest including whether girls in female-headed households were more likely to be sexually active and have higher ATIBC scores, whether Catholics will have lower ATIBC scores, whether spanish preference speakers have lower ATIBC scores, whether working mothers' children, or more highly educated mothers' children were more sexually active and have higher scores, whether religiosity lowers scores, whether higher educational aspirations increases scores, whether childrens' beliefs that most of the friends use contraceptive is related to higher cores, and whether clearer longterm goals are related to higher scores. The attitude scale was based on Kirby's and Cvetkovich and Grote's work and focused on peer influence, parental attitudes, and strength of intention to use contraceptives. Other measures are identified by specific questions, i.e., clarity of longterm goals is measured by the question: I have a clear idea of where I'm headed in the future, and I know what I want out of life. The results indicated that 4 variables were significantly associated with ATIBC scores: 1) lower scores were associated with teenagers who had mothers with low education (2nd-9th grades), and 2) teenagers who spoke Spanish best; 3) perceived importance of religion was significantly related to lower ATIBC scores such that great importance was related to low scores and little importance was related to high scores; and 4) teenagers' belief about their friends' potential

  2. Development of helicopter attitude axes controlled hover flight without pilot assistance and vehicle crashes

    Science.gov (United States)

    Simon, Miguel

    In this work, we show how to computerize a helicopter to fly attitude axes controlled hover flight without the assistance of a pilot and without ever crashing. We start by developing a helicopter research test bed system including all hardware, software, and means for testing and training the helicopter to fly by computer. We select a Remote Controlled helicopter with a 5 ft. diameter rotor and 2.2 hp engine. We equip the helicopter with a payload of sensors, computers, navigation and telemetry equipment, and batteries. We develop a differential GPS system with cm accuracy and a ground computerized navigation system for six degrees of freedom (6-DoF) free flight while tracking navigation commands. We design feedback control loops with yet-to-be-determined gains for the five control "knobs" available to a flying radio-controlled (RC) miniature helicopter: engine throttle, main rotor collective pitch, longitudinal cyclic pitch, lateral cyclic pitch, and tail rotor collective pitch. We develop helicopter flight equations using fundamental dynamics, helicopter momentum theory and blade element theory. The helicopter flight equations include helicopter rotor equations of motions, helicopter rotor forces and moments, helicopter trim equations, helicopter stability derivatives, and a coupled fuselage-rotor helicopter 6-DoF model. The helicopter simulation also includes helicopter engine control equations, a helicopter aerodynamic model, and finally helicopter stability and control equations. The derivation of a set of non-linear equations of motion for the main rotor is a contribution of this thesis work. We design and build two special test stands for training and testing the helicopter to fly attitude axes controlled hover flight, starting with one axis at a time and progressing to multiple axes. The first test stand is built for teaching and testing controlled flight of elevation and yaw (i.e., directional control). The second test stand is built for teaching and

  3. Tuberculosis knowledge, attitudes, and practices among northern Ethiopian prisoners: Implications for TB control efforts.

    Science.gov (United States)

    Adane, Kelemework; Spigt, Mark; Johanna, Laturnus; Noortje, Dorscheidt; Abera, Semaw Ferede; Dinant, Geert-Jan

    2017-01-01

    Although awareness is an important component in tuberculosis (TB) control, we do not know how much Ethiopian prisoners know about TB. This study assessed the level of knowledge, attitudes, and practices (KAP) of prisoners about TB in eight northern Ethiopian prisons. Data were collected cross-sectionally from 615 prisoners using a standardized questionnaire between March and May 2016. The outcome variables were defined considering the basic elements about TB. Out of 615 prisoners, only 37.7% mentioned bacteria as a cause of TB while 21.7% related TB to exposure to cold wind. Eighty-eight per cent correctly mentioned the aerial route of TB transmission and 27.3% had perceived stigma towards TB. The majority (63.7%) was not aware of the possibility of getting multi-drug-resistant strains when they would not adhere to treatment. Overall, only 24% knew the basic elements about TB, 41% had favorable attitudes, and 55% had a good practice. Prisoners who were urban residents were generally more knowledgeable than rural residents (adjusted OR = 2.16; 95% CI = 1.15-4.06). Illiterates were found to be less knowledgeable (adjusted OR = 0.17; 95% CI = 0.06-0.46), less likely to have a favorable attitude (adjusted OR = 0.31; 95% CI = 0.15-0.64), and less good practice (adjusted OR = 0.35; 95% CI = 0.18-0.69). Significant differences were also observed between the different study prisons. Knowledge of prisoners regarding the cause of TB and consequences of non-adherence to TB treatment was low. Knowledge on the transmission, symptoms, and prevention was fairly high. Health education interventions, focused on the cause and the translation of the knowledge to appropriate practices, are needed in all the study prisons. Special attention should be given to less educated prisoners, and to prisons with a high number of prisoners and those in remote areas.

  4. Electrospray Thrusters for Attitude Control of a 1-U CubeSat

    Science.gov (United States)

    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.

  5. Attitudes and behavioral response toward key tobacco control measures from the FCTC among Chinese urban residents

    Directory of Open Access Journals (Sweden)

    Li Fuzhong

    2007-09-01

    Full Text Available Abstract Background The Chinese National People's Congress ratified the WHO Framework Convention on Tobacco Control (FCTC on 27 August 2005, signaling China's commitment to implement tobacco control policies and legislation consistent with the treaty. This study was designed to examine attitudes towards four WHO FCTC measures among Chinese urban residents. Methods In a cross-sectional design study, survey data were collected from two Chinese urban cities involving a sample of 3,003 residents aged 15 years or older. Through a face-to-face interview, respondents were asked about attitudes toward four tobacco control measures developed by the WHO FCTC. Data on the four dependent measures were analyzed using multivariate logistic regression analyses. Using descriptive statistics, potential change in smoking behavior that smokers might make in response to increasing cigarette prices is also reported. Results 81.8% of the respondents in the study sample supported banning smoking in public places, 68.8% favored increasing the cigarette tax, 85.1% supported health warnings on cigarette packages, and 85.7% favored banning tobacco advertising. The likelihood to support these measures was associated with gender, educational level, and personal income. Smokers were less likely to support these measures than non-smokers, with decreased support expressed by daily smokers compared to occasional smokers, and heavy smokers compared to light smokers. The proportion of switching to cheaper cigarette brands, decreasing smoking, and quitting smoking altogether with increased cigarette prices were 29.1%, 30.90% and 40.0% for occasional smokers, respectively; and 30.8%, 32.7% and 36.5% for daily smokers, respectively. Conclusion Results from this study indicate strong public support in key WHO FCTC measures and that increases in cigarette price may reduce tobacco consumption among Chinese urban residents. Findings from this study have implications with respect to

  6. Effect of locus of control on disordered eating in athletes: the mediational role of self-regulation of eating attitudes.

    Science.gov (United States)

    Scoffier, S; Paquet, Y; d'Arripe-Longueville, F

    2010-08-01

    This study examined the influence of locus of control on disordered eating as mediated by the self-regulation of eating attitudes. The assessment instruments were adapted for athletes as the entire sample of 179 volunteer University students (M(age)=21.12; SD=2.87) were all regularly involved in competition. The results showed that (a) an internal locus of control had a positive influence on the self-regulation of eating attitudes in social interaction contexts; (b) self-regulatory eating attitudes had a negative influence on disordered eating in contexts of negative affect, social interaction, and lack of anticipation of consequences on performance; and (c) an internal locus of control had an influence on disordered eating through the mediation of self-regulatory eating attitudes in social interaction contexts, and an external locus of control attributed to the coach and sports friends had an influence on disordered eating through the mediation of self-regulatory eating attitudes in contexts of negative affect, social interaction and lack of anticipation of consequences on performance. This study, combined with an earlier study from Scoffier, Maïano, and d'Arripe-Longueville (2009) on the antecedents of athletes' eating disorders, suggests the powerful impact of the social environment on the development of disordered eating in athletes. 2010 Elsevier Ltd. All rights reserved.

  7. [Intention, attitude, subjective norms and perception of control in Spanish adolescents about using Double Dutch].

    Science.gov (United States)

    Hernández, Oscar; Goulet, Céline; Lampron, Annie

    2005-09-01

    With adolescence, boys and girls reach their sexual maturity and initiate their sexual encounters. They very frequently adopt risk behaviors as they tend not to use any contraceptive methods. Today's trend in relation to contraceptive methods is to recommend the combined utilization of condom and pill. In comparison to other methods, this last one, known as the Double Dutch (DD) method, has the advantage of preventing pregnancy and STD's, at the same time it increases the efficiency of contraception. Using the Theory of Planned Behavior the purpose of the study was to measure the intention, attitude, subjective norm and perceived behavioral control towards the utilization of the DD method among 15-16 year-old Spanish students and to determine the relationships among these variables. The results indicate that adolescents show favorable intention, attitude and subjective norm toward the utilization of the DD method. They seem to be more worried about pregnancy prevention than about STDs'prevention. Parents seem to be the most important reference people for adolescents, followed by their friends; the results show that at this age, adolescents tend to take into consideration these reference people's opinion.

  8. MERCATOR: Methods and Realization for Control of the Attitude and the Orbit of spacecraft

    Science.gov (United States)

    Tavernier, Gilles; Campan, Genevieve

    1993-01-01

    Since 1974, CNES has been involved in geostationary positioning. Among different entities participating in operations and their preparation, the Flight Dynamics Center (FDC) is in charge of performing the following tasks: orbit determination; attitude determination; computation, monitoring, and calibration of orbit maneuvers; computation, monitoring, and calibration of attitude maneuvers; and operational predictions. In order to fulfill this mission, the FDC receives telemetry from the satellite and localization measurements from ground stations (e.g., CNES, NASA, INTELSAT). These data are processed by space dynamics programs integrated in the MERCATOR system which is run on SUN workstations (UNIX O.S.). The main features of MERCATOR are redundancy, modularity, and flexibility: efficient, flexible, and user friendly man-machine interface; and four identical SUN stations redundantly linked in an Ethernet network. Each workstation can perform all the tasks from data acquisition to computation results dissemination through a video network. A team of four engineers can handle the space mechanics aspects of a complete geostationary positioning from the injection into a transfer orbit to the final maneuvers in the station-keeping window. MERCATOR has been or is to be used for operations related to more than ten geostationary positionings. Initially developed for geostationary satellites, MERCATOR's methodology was also used for satellite control centers and can be applied to a wide range of satellites and to future manned missions.

  9. Numerical analysis of orbital transfers to Mars using solar sails and attitude control

    Science.gov (United States)

    Pereira, M. C.; de Melo, C. F.; Meireles, L. G.

    2017-10-01

    Solar sails present a promising alternative method of propulsion for the coming phases of the space exploration. With the recent advances in materials engineering, the construction of lighter and more resistant materials capable of impelling spaceships with the use of solar radiation pressure has become increasingly viable technologically and economically. The studies, simulations and analysis of orbital transfers from Earth to Mars proposed in this work were implemented considering the use of a flat solar sail. Maneuvers considering the delivery of a sailcraft from a Low Earth Orbit to the border of the Earth’s sphere of influence and interplanetary trajectories to Mars were investigated. A set of simulations were implemented varying the attitude of the sail relative to the Sun. Results show that a sailcraft can carry out transfers with final velocity with respect to Mars smaller than the interplanetary Patched-conic approximation, although this requires a longer time of transfers, provided the attitude of the sailcraft relative to the Sun can be controlled in some points of the trajectories.

  10. Uncooled micro-earth sensor for micro-satellite attitude control: Earth remote sensing application

    Science.gov (United States)

    Fourniols, J.-Y.; Soto-Romero, G.; Bony, F.; Vergnenègre, C.; Simonne, J.-J.; Esteve, D.; Albukerque, J.

    2017-11-01

    MEMS technology now makes possible to produce active microdevices combining detection, signal processing, and data storage with accuracy and compactness. In view of their characteristics, it can be expected that such microsensors will be used extensively in space applications dedicated to micro and nano satellites. For this purpose, a specific investigation dealing with the complete development of a micro-earth sensor used for attitude control of Low Earth Orbit satellites is under realization and test. Based on an infrared uncooled 320x240 microbolometer the experimental characterization of the final active system consists of three microsensors linear arrays of 240 pixels of the same technology, radialy spaced at 120°, watching and receiving earth IR radiations. The transition between excited and non excited pixels will determine the IR image of the Earth/Space transition hidden in IR atmosphere response. Specific on-chip algorithms have been implemented to extract the transition and compute the attitude satellite position in roll and pitch. The complete physical system modeling of one linear 240 pixels array including earth models, optic characteristics, microbolometer behavioral models, mixed analog/digital electronics and associated algorithms is consistent (at +/-8% ) with the breadboard measurements.

  11. Solar Sail Attitude Control System for the NASA Near Earth Asteroid Scout Mission

    Science.gov (United States)

    Orphee, Juan; Diedrich, Ben; Stiltner, Brandon; Becker, Chris; Heaton, Andrew

    2017-01-01

    An Attitude Control System (ACS) has been developed for the NASA Near Earth Asteroid (NEA) Scout mission. The NEA Scout spacecraft is a 6U cubesat with an eighty-six square meter solar sail for primary propulsion that will launch as a secondary payload on the Space Launch System (SLS) Exploration Mission 1 (EM-1) and rendezvous with a target asteroid after a two year journey, and will conduct science imagery. The spacecraft ACS consists of three major actuating subsystems: a Reaction Wheel (RW) control system, a Reaction Control System (RCS), and an Active Mass Translator (AMT) system. The reaction wheels allow fine pointing and higher rates with low mass actuators to meet the science, communication, and trajectory guidance requirements. The Momentum Management System (MMS) keeps the speed of the wheels within their operating margins using a combination of solar torque and the RCS. The AMT is used to adjust the sign and magnitude of the solar torque to manage pitch and yaw momentum. The RCS is used for initial de-tumble, performing a Trajectory Correction Maneuver (TCM), and performing momentum management about the roll axis. The NEA Scout ACS is able to meet all mission requirements including attitude hold, slews, pointing for optical navigation and pointing for science with margin and including flexible body effects. Here we discuss the challenges and solutions of meeting NEA Scout mission requirements for the ACS design, and present a novel implementation of managing the spacecraft Center of Mass (CM) to trim the solar sail disturbance torque. The ACS we have developed has an applicability to a range of potential missions and does so in a much smaller volume than is traditional for deep space missions beyond Earth.

  12. Case-based e-learning to improve the attitude of medical students towards occupational health, a randomised controlled trial.

    Science.gov (United States)

    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.

  13. Integrated 6-DOF Orbit-Attitude Dynamical Modeling and Control Using Geometric Mechanics

    Directory of Open Access Journals (Sweden)

    Ling Jiang

    2017-01-01

    Full Text Available The integrated 6-DOF orbit-attitude dynamical modeling and control have shown great importance in various missions, for example, formation flying and proximity operations. The integrated approach yields better performances than the separate one in terms of accuracy, efficiency, and agility. One challenge in the integrated approach is to find a unified representation for the 6-DOF motion with configuration space SE(3. Recently, exponential coordinates of SE(3 have been used in dynamics and control of the 6-DOF motion, however, only on the kinematical level. In this paper, we will improve the current method by adopting exponential coordinates on the dynamical level, by giving the relation between the second-order derivative of exponential coordinates and spacecraft’s accelerations. In this way, the 6-DOF motion in terms of exponential coordinates can be written as a second-order system with a quite compact form, to which a broader range of control theories, such as higher-order sliding modes, can be applied. For a demonstration purpose, a simple asymptotic tracking control law with almost global convergence is designed. Finally, the integrated modeling and control are applied to the body-fixed hovering over an asteroid and verified by a simulation, in which absolute motions of the spacecraft and asteroid are simulated separately.

  14. Fast spacecraft adaptive attitude tracking control through immersion and invariance design

    Science.gov (United States)

    Wen, Haowei; Yue, Xiaokui; Li, Peng; Yuan, Jianping

    2017-10-01

    This paper presents a novel non-certainty-equivalence adaptive control method for the attitude tracking control problem of spacecraft with inertia uncertainties. The proposed immersion and invariance (I&I) based adaptation law provides a more direct and flexible approach to circumvent the limitations of the basic I&I method without employing any filter signal. By virtue of the adaptation high-gain equivalence property derived from the proposed adaptive method, the closed-loop adaptive system with a low adaptation gain could recover the high adaptation gain performance of the filter-based I&I method, and the resulting control torque demands during the initial transient has been significantly reduced. A special feature of this method is that the convergence of the parameter estimation error has been observably improved by utilizing an adaptation gain matrix instead of a single adaptation gain value. Numerical simulations are presented to highlight the various benefits of the proposed method compared with the certainty-equivalence-based control method and filter-based I&I control schemes.

  15. Attitude Dynamics and Tracking Control of Spacecraft in the Presence of Gravity Oblateness Perturbations

    Directory of Open Access Journals (Sweden)

    Achim IONITA

    2016-03-01

    Full Text Available The orbital docking represents a problem of great importance in aerospace engineering. The paper aims to perform an analysis of docking maneuvers between a chaser vehicle and a target vehicle in permanent LEO (low earth orbit. The work begins with a study of the attitude dynamics modeling intended to define the strategy that facilitates the chaser movement toward a docking part of the target. An LQR (linear quadratic regulator approach presents an optimal control design that provides linearized closed-loop error dynamics for tracking a desired quaternion. The control law formulation is combined with the control architecture based on SDRE (State Dependent Riccati equation technique for rotational maneuvers, including the Earth oblateness perturbation. The chaser body-fixed frame must coincide with the target body-fixed frame at the docking moment. Then the implementation of the control architecture based on LQR technique using the computational tool MATLAB is carried out. In simulation of the docking strategy V-R bar operations are analyzed and the minimum accelerations needs the control of chaser vehicle. The simulation analysis of those maneuvers considered for a chaser vehicle and a target vehicle in LEO orbit is validated in a case study.

  16. Relations of Children's Effortful Control and Teacher-Child Relationship Quality to School Attitudes in a Low-Income Sample.

    Science.gov (United States)

    Silva, Kassondra M; Spinrad, Tracy L; Eisenberg, Nancy; Sulik, Michael J; Valiente, Carlos; Huerta, Snjezana; Edwards, Alison; Eggum, Natalie D; Kupfer, Anne S; Lonigan, Christopher J; Phillips, Beth M; Wilson, Shauna B; Clancy-Menchetti, Jeanine; Landry, Susan H; Swank, Paul R; Assel, Michael A; Taylor, Heather B

    2011-01-01

    RESEARCH FINDINGS: The purpose of this study was to examine the relations of children's effortful control and quality of relationships with teachers to school attitudes longitudinally in an ethnically diverse and economically disadvantaged sample. Data were collected as part of a larger intervention project during mid-fall, winter, and late spring (ns = 823, 722, and 758, respectively) for 2 cohorts of 3- to 5-year-olds (collected during 2 different school years). Children's effortful control was assessed in the fall with parents' and teachers' reports and 2 behavioral measures. Teacher-child relationship quality was assessed mid-year with teachers' reports of closeness and conflict. Attitudes toward school were assessed in late spring using teachers' and students' reports of school avoidance and liking. Effortful control, in general, was positively correlated with teacher-child closeness and school liking and negatively correlated with conflict and school avoidance. Using structural equation modeling and controlling for sex and ethnicity, we found that effortful control was positively related to teacher-child relationship quality, which in turn was positively related to school attitudes. Furthermore, the relation of effortful control to school attitudes was mediated by teacher-child relationship quality. PRACTICE OR POLICY: Results provide evidence for the importance of relational processes that take place within the classroom context and have implications for teachers and clinicians working to increase school success in ethnic minority and low-income children.

  17. Space Satellite Dynamics with Applications to Sunlight Pressure Attitude Control. Ph.D. Thesis

    Science.gov (United States)

    Stuck, B. W.

    1972-01-01

    A research program into three aspects of space satellite dynamics was carried out. First, a four-dimensional space-time formulation of Newtonian mechanics is developed. This theory allows a new physical interpretation of the conservation theorems of mechanics first derived rigorously by Noether. Second, a new concept for estimating the three angles which specify the orientation in space of a rigid body is presented. Two separate methods for implementing this concept are discussed, one based on direction cosines, the other on quaternions. Two examples are discussed: constant orientation in space, and constant rate of change of the three angles with time. Third, two synchronous equatorial orbit communication satellite designs which use sunlight pressure to control their attitude are analyzed. Each design is equipped with large reflecting surfaces, called solar sails, which can be canted in different directions to generate torques to correct pointing errors.

  18. Optimizing the Attitude Control of Small Satellite Constellations for Rapid Response Imaging

    Science.gov (United States)

    Nag, S.; Li, A.

    2016-12-01

    Distributed Space Missions (DSMs) such as formation flight and constellations, are being recognized as important solutions to increase measurement samples over space and time. Given the increasingly accurate attitude control systems emerging in the commercial market, small spacecraft now have the ability to slew and point within few minutes of notice. In spite of hardware development in CubeSats at the payload (e.g. NASA InVEST) and subsystems (e.g. Blue Canyon Technologies), software development for tradespace analysis in constellation design (e.g. Goddard's TAT-C), planning and scheduling development in single spacecraft (e.g. GEO-CAPE) and aerial flight path optimizations for UAVs (e.g. NASA Sensor Web), there is a gap in open-source, open-access software tools for planning and scheduling distributed satellite operations in terms of pointing and observing targets. This paper will demonstrate results from a tool being developed for scheduling pointing operations of narrow field-of-view (FOV) sensors over mission lifetime to maximize metrics such as global coverage and revisit statistics. Past research has shown the need for at least fourteen satellites to cover the Earth globally everyday using a LandSat-like sensor. Increasing the FOV three times reduces the need to four satellites, however adds image distortion and BRDF complexities to the observed reflectance. If narrow FOV sensors on a small satellite constellation were commanded using robust algorithms to slew their sensor dynamically, they would be able to coordinately cover the global landmass much faster without compensating for spatial resolution or BRDF effects. Our algorithm to optimize constellation satellite pointing is based on a dynamic programming approach under the constraints of orbital mechanics and existing attitude control systems for small satellites. As a case study for our algorithm, we minimize the time required to cover the 17000 Landsat images with maximum signal to noise ratio fall

  19. Experimental study on cascaded attitude angle control of a multi-rotor unmanned aerial vehicle with the simple internal model control method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jun Beom [Dept. of Aviation Maintenance, Dongwon Institute of Science and Technology, Yangsan (Korea, Republic of); Byun, Young Seop; Jeong, Jin Seok; Kim, Jeong; Kang, Beom Soo [Dept. of Aerospace Engineering, Pusan National University, Busan (Korea, Republic of)

    2016-11-15

    This paper proposes a cascaded control structure and a method of practical application for attitude control of a multi-rotor Unmanned aerial vehicle (UAV). The cascade control, which has tighter control capability than a single-loop control, is rarely used in attitude control of a multi-rotor UAV due to the input-output relation, which is no longer simply a set-point to Euler angle response transfer function of a single-loop PID control, but there are multiply measured signals and interactive control loops that increase the complexity of evaluation in conventional way of design. However, it is proposed in this research a method that can optimize a cascade control with a primary and secondary loops and a PID controller for each loop. An investigation of currently available PID-tuning methods lead to selection of the Simple internal model control (SIMC) method, which is based on the Internal model control (IMC) and direct-synthesis method. Through the analysis and experiments, this research proposes a systematic procedure to implement a cascaded attitude controller, which includes the flight test, system identification and SIMC-based PID-tuning. The proposed method was validated successfully from multiple applications where the application to roll axis lead to a PID-PID cascade control, but the application to yaw axis lead to that of PID-PI.

  20. Attitude dynamics and control of a spacecraft like a robotic manipulator when implementing on-orbit servicing

    Science.gov (United States)

    Da Fonseca, Ijar M.; Goes, Luiz C. S.; Seito, Narumi; da Silva Duarte, Mayara K.; de Oliveira, Élcio Jeronimo

    2017-08-01

    In space the manipulators working space is characterized by the microgravity environment. In this environment the spacecraft floats and its rotational/translational motion may be excited by any internal and external disturbances. The complete system, i.e., the spacecraft and the associated robotic manipulator, floats and is sensitive to any reaction force and torque related to the manipulator's operation. In this sense the effort done by the robot may result in torque about the system center of mass and also in forces changing its translational motion. This paper analyzes the impact of the robot manipulator dynamics on the attitude motion and the associated control effort to keep the attitude stable during the manipulator's operation. The dynamics analysis is performed in the close proximity phase of rendezvous docking/berthing operation. In such scenario the linear system equations for the translation and attitude relative motions are appropriate. The computer simulations are implemented for the relative translational and rotational motion. The equations of motion have been simulated through computer by using the MatLab software. The LQR and the PID control laws are used for linear and nonlinear control, respectively, aiming to keep the attitude stable while the robot is in and out of service. The gravity-gradient and the residual magnetic torque are considered as external disturbances. The control efforts are analyzed for the manipulator in and out of service. The control laws allow the system stabilization and good performance when the manipulator is in service.

  1. Knowledge, attitude and practice of exercise for plasma blood glucose control among patients with type-2 diabetes.

    Science.gov (United States)

    Awotidebe, Taofeek O; Adedoyin, Rufus A; Afolabi, Mubaraq A; Opiyo, Rose

    2016-01-01

    Exercise plays significant role in the health outcomes of patients with diabetes, however, little is known about patients' knowledge of exercise for plasma blood glucose control among patients with type-2 diabetes (T2D). This study investigated knowledge, attitude and practice (KAP) of exercise for plasma blood glucose control among patients with T2D. This cross-sectional study recruited 299 patients with T2D (male=105; female=194) from selected government hospitals in Osun State, Nigeria using purposive sampling technique. Validated questionnaires were used to assess of exercise for plasma blood glucose control and socioeconomic status (SES) of the patients. Data were analysed using descriptive and inferential statistics. Alpha level was set at knowledge of exercise whilst 269(90.0%) had negative attitude to exercise practice. Less than a third, 82(27.4%) engaged in exercise practice for plasma blood glucose control. There was significant association between knowledge and practice of exercise ((2)=12.535; p=0.002). Furthermore, significant associations were found between knowledge and gender ((2)=11.453; p=0.003), and socioeconomic status ((2)=29.127, p=0.001) but not associated with attitude towards exercise (p>0.05). Patients with demonstrated good knowledge of exercise for plasma blood glucose control but reported negative attitude and poor practice of exercise. Copyright © 2016. Published by Elsevier Ltd.

  2. Spacecraft attitude maneuver control using two parallel mounted 3-DOF spherical actuators

    Directory of Open Access Journals (Sweden)

    Guidan Li

    2017-02-01

    Full Text Available A parallel configuration using two 3-degree-of-freedom (3-DOF spherical electromagnetic momentum exchange actuators is investigated for large angle spacecraft attitude maneuvers. First, the full dynamic equations of motion for the spacecraft system are derived by the Newton-Euler method. To facilitate computation, virtual gimbal coordinate frames are established. Second, a nonlinear control law in terms of quaternions is developed via backstepping method. The proposed control law compensates the coupling torques arising from the spacecraft rotation, and is robust against the external disturbances. Then, the singularity problem is analyzed. To avoid singularities, a modified weighed Moore-Pseudo inverse velocity steering law based on null motion is proposed. The weighted matrices are carefully designed to switch the actuators and redistribute the control torques. The null motion is used to reorient the rotor away from the tilt angle saturation state. Finally, numerical simulations of rest-to-rest maneuvers are performed to validate the effectiveness of the proposed method.

  3. Attitudes, subjective norm, perceived behavioral control, and intentions related to adult smoking cessation after coronary artery bypass graft surgery.

    Science.gov (United States)

    Bursey, M; Craig, D

    2000-01-01

    The purpose of this study was to examine the relationships between intention, attitudes, subjective norm, and perceived behavioral control related to smoking cessation in adults after initial coronary artery bypass graft surgery (CABG). The theoretical framework for the study was derived from Ajzen's Theory of Planned Behavior. Intention, the global and belief-based measures of attitude, subjective norm, and perceived behavioral control were measured with the Determinants of Adult Smoking Cessation (DOASC) Questionnaire developed by the investigator. Thirty-two adult smokers completed the questionnaire 2 to 3 weeks following hospital discharge. Four weeks after the questionnaire completion, a follow-up telephone call was used to determine the participants' current smoking status. The study results indicated that there was a statistically significant relationship between the intention to quit smoking after CABG and the global measure of attitude, and perceived behavioral control. This study highlights some of the beliefs about the outcomes of quitting smoking permanently after CABG which may underlie attitudes, subjective norm, and perceived behavioral control in this population. Implications for theory, practice, and research are discussed.

  4. Predicting Participation in Group Parenting Education in an Australian Sample: The Role of Attitudes, Norms, and Control Factors

    Science.gov (United States)

    White, Katherine M.; Wellington, Larne

    2009-01-01

    We examined the theory of planned behavior (TPB) in predicting intentions to participate in group parenting education. One hundred and seventy-six parents (138 mothers and 38 fathers) with a child under 12 years completed TPB items assessing attitude, subjective norms, perceived behavioral control (PBC), and two additional social influence…

  5. The prevalence of weight – controlling attitude and eating disorders and their association with anthropometric indices in female adolescent students

    Directory of Open Access Journals (Sweden)

    mohamad hasan Eftekhari

    2015-01-01

    Full Text Available Background : Adolescence is one of the most critical growth periods in the human's life. Eating disorder is one of the most common nutritional-psychological disorders in this period, which can lead to acute and chronic physical and mental problems. Therefore, regarding the importance of the topic, the present study was designed to determine the prevalence of weight – controlling attitude and eating disorders, and their association with anthropometric indices in female adolescent school students. Materials and Methods: The present study was a cross-sectional descriptive analytical study. 594 high school adolescent girls were selected using multi-stage random sampling method. Nutritional attitude was assessed by use of a nutritional attitude questionnaire. Another specific questionnaire was used to gather demographic and anthropometric information. Data analysis was done using SPSS software, independent t- test and Chi-square (P˂0.05. Results: The information shows that 80% of the studied population are at risk of eating disorders. The number of the obese , over weight and underweight students were significantly more in the group with nutritional attitude disorders. Conclusion: Due to the high prevalence of eating disorders in adolescent girls, and the concomitant obesity and underweight with these disorders, the correction of these attitude could be mentioned as a health priority in this city

  6. Integrated Orbit, Attitude, and Structural Control Systems Design for Space Solar Power Satellites

    Science.gov (United States)

    Wie, Bong; Roithmayr, Carlos M.

    2001-01-01

    The major objective of this study is to develop an integrated orbit, attitude, and structural control systems architecture for very large Space Solar Power Satellites (SSPS) in geosynchronous orbit. This study focuses on the 1.2-GW Abacus SSPS concept characterized by a 3.2 x 3.2 km solar-array platform, a 500-m diameter microwave beam transmitting antenna, and a 500 x 700 m earth-tracking reflector. For this baseline Abacus SSPS configuration, we derive and analyze a complete set of mathematical models, including external disturbances such as solar radiation pressure, microwave radiation, gravity-gradient torque, and other orbit perturbation effects. The proposed control systems architecture utilizes a minimum of 500 1-N electric thrusters to counter, simultaneously, the cyclic pitch gravity-gradient torque, the secular roll torque caused by an offset of the center-of-mass and center-of-pressure, the cyclic roll/yaw microwave radiation torque, and the solar radiation pressure force whose average value is about 60 N.

  7. Integrated Orbit, Attitude, and Structural Control System Design for Space Solar Power Satellites

    Science.gov (United States)

    Woods-Vedeler, Jessica (Technical Monitor); Moore, Chris (Technical Monitor); Wie, Bong; Roithmayr, Carlos

    2001-01-01

    The major objective of this study is to develop an integrated orbit, attitude, and structural control system architecture for very large Space Solar Power Satellites (SSPS) in geosynchronous orbit. This study focuses on the 1.2-GW Abacus SSPS concept characterized by a 3.2 x 3.2 km solar-array platform, a 500-m diameter microwave beam transmitting antenna, and a 500 700 m earth-tracking reflector. For this baseline Abacus SSPS configuration, we derive and analyze a complete set of mathematical models, including external disturbances such as solar radiation pressure, microwave radiation, gravity-gradient torque, and other orbit perturbation effects. The proposed control system architecture utilizes a minimum of 500 1-N electric thrusters to counter, simultaneously, the cyclic pitch gravity-gradient torque, the secular roll torque caused by an o.set of the center-of-mass and center-of-pressure, the cyclic roll/yaw microwave radiation torque, and the solar radiation pressure force whose average value is about 60 N.

  8. Attitudes Toward Obese Persons and Weight Locus of Control in Chinese Nurses: A Cross-sectional Survey.

    Science.gov (United States)

    Wang, Yan; Ding, Ye; Song, Daoping; Zhu, Daqiao; Wang, Jianrong

    2016-01-01

    Obese individuals frequently experience weight-related bias or discrimination-even in healthcare settings. Although obesity bias has been associated with several demographic factors, little is known about the association of weight locus of control with bias against overweight persons or about weight bias among Chinese health professionals. The aim of the study was to examine attitudes toward obese patients in a sample of Chinese registered nurses (RNs) and the relationship between weight bias and nurses' weight locus of control. RNs working in nine community health service centers across Shanghai, China, answered three self-report questionnaires: The Attitudes Toward Obese Persons Scale (ATOP), the External Weight Locus of Control Subscale (eWLOC) from the Dieting Belief Scale, and a sociodemographic profile. Hierarchical, stepwise, multiple regression was used to predict ATOP scores. From among 385 invited, a total of 297 RNs took part in the study (77.1% response rate). Participants scored an average of 71.04 on the ATOP, indicating slightly positive attitudes toward obese persons, and 30.08 on the eWLOC, indicating a belief in the uncontrollability of body weight. Using hierarchical, stepwise, multiple regression, two predictors of ATOP scores were statistically significant (eWLOC scores and status as a specialist rather than generalist nurse), but explained variance was low. Chinese RNs seemed to have relatively neutral or even slightly positive attitudes toward obese persons. Those nurses who believed that obesity was beyond the individual's control or worked in specialties were more likely to have positive attitudes toward obese people. Improved understanding of the comprehensive etiology of obesity is needed.

  9. Educating early childhood care and education providers to improve knowledge and attitudes about reporting child maltreatment: A randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Ben Mathews

    Full Text Available Early childhood care and education providers (CCPs work with over 7 million young children. These children are vulnerable to physical, sexual and emotional abuse, and neglect. However, CCPs make less than 1% of all reports of suspected child abuse and neglect that are made to child protective services. CCPs are therefore an untapped resource in the public health response to child maltreatment. However, their knowledge and attitudes about duties to report child maltreatment are poorly understood. Moreover, no rigorous research has tested whether their knowledge and attitudes about reporting child maltreatment can be improved. These gaps in knowledge are important because knowledge of the duty and positive attitudes towards it produce more effective reporting, and little evidence exists about how to enhance cognitive and affective attributes. Using the CONSORT approach, we report a single-blind test-retest randomized controlled trial evaluating iLook Out for Child Abuse, a customized online educational intervention for CCPs to increase knowledge and attitudes towards the reporting duty. 762 participants were randomized with results analyzed for 741 participants (372 in the intervention group; 369 in the control. Knowledge of the reporting duty increased in the intervention group from 13.54 to 16.19 out of 21 (2.65 increase, 95% CI: (2.37, 2.93; large effect size 0.95, p < 0.001; the control group remained stable, moving from 13.54 to 13.59 (0.05 increase, 95% CI: (-0.12, 0.22; negligible effect size 0.03, p = 0.684. Attitudes were enhanced on all 13 items for the intervention group, remaining stable in the control, with significant differences between groups on all items (p < 0.05. Gains were largely sustained at four month follow-up. Findings support education for CCPs and other professions. Future research should also explore effects of education on reporting behavior.US National Institutes of Health NCT02225301.

  10. Full quaternion based finite-time cascade attitude control approach via pulse modulation synthesis for a spacecraft.

    Science.gov (United States)

    Mazinan, A H; Pasand, M; Soltani, B

    2015-09-01

    In the aspect of further development of investigations in the area of spacecraft modeling and analysis of the control scheme, a new hybrid finite-time robust three-axis cascade attitude control approach is proposed via pulse modulation synthesis. The full quaternion based control approach proposed here is organized in association with both the inner and the outer closed loops. It is shown that the inner closed loop, which consists of the sliding mode finite-time control approach, the pulse width pulse frequency modulator, the control allocation and finally the dynamics of the spacecraft is realized to track the three-axis referenced commands of the angular velocities. The pulse width pulse frequency modulators are in fact employed in the inner closed loop to accommodate the control signals to a number of on-off thrusters, while the control allocation algorithm provides the commanded firing times for the reaction control thrusters in the overactuated spacecraft. Hereinafter, the outer closed loop, which consists of the proportional linear control approach and the kinematics of the spacecraft is correspondingly designed to deal with the attitude angles that are presented by quaternion vector. It should be noted that the main motivation of the present research is to realize a hybrid control method by using linear and nonlinear terms and to provide a reliable and robust control structure, which is able to track time varying three-axis referenced commands. Subsequently, a stability analysis is presented to verify the performance of the overall proposed cascade attitude control approach. To prove the effectiveness of the presented approach, a thorough investigation is presented compared to a number of recent corresponding benchmarks. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Geometric Collocation Method on SO(3 with Application to Optimal Attitude Control of a 3D Rotating Rigid Body

    Directory of Open Access Journals (Sweden)

    Xiaojia Xiang

    2015-01-01

    Full Text Available The collocation method is extended to the special orthogonal group SO(3 with application to optimal attitude control (OAC of a rigid body. A left-invariant rigid-body attitude dynamical model on SO(3 is established. For the left invariance of the attitude configuration equation in body-fixed frame, a geometrically exact numerical method on SO(3, referred to as the geometric collocation method, is proposed by deriving the equivalent Lie algebra equation in so(3 of the left-invariant configuration equation. When compared with the general Gauss pseudo-spectral method, the explicit RKMK, and Lie group variational integrator having the same order and stepsize in numerical tests for evolving a free-floating rigid-body attitude dynamics, the proposed method is higher in accuracy, time performance, and structural conservativeness. In addition, the numerical method is applied to solve a constrained OAC problem on SO(3. The optimal control problem is transcribed into a nonlinear programming problem, in which the equivalent Lie algebra equation is being considered as the defect constraints instead of the configuration equation. The transcription method is coordinate-free and does not need chart switching or special handling of singularities. More importantly, with the numerical advantage of the geometric collocation method, the proposed OAC method may generate satisfying convergence rate.

  12. Knowledge, attitudes and practices (KAP about rabies prevention and control: a community survey in Tanzania.

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    Maganga Sambo

    2014-12-01

    Full Text Available Despite being entirely preventable, canine rabies still kills 55,000 people/year in developing countries. Information about local beliefs and practices can identify knowledge gaps that may affect prevention practices and lead to unnecessary deaths.We investigated knowledge, attitudes and practices related to rabies and its prevention and control amongst a cross-section of households (n = 5,141 in urban and rural areas of central, southern and northern Tanzania. Over 17% of respondents owned domestic dogs (average of 2.3 dogs/household,>95% had heard about rabies, and>80% knew that rabies is transmitted through dog bites. People who (1 had greater education, (2 originated from areas with a history of rabies interventions, (3 had experienced exposure by a suspect rabid animal, (4 were male and (5 owned dogs were more likely to have greater knowledge about the disease. Around 80% of respondents would seek hospital treatment after a suspect bite, but only 5% were aware of the need for prompt wound cleansing after a bite. Although>65% of respondents knew of dog vaccination as a means to control rabies, only 51% vaccinated their dogs. Determinants of dog vaccination included (1 being a male-headed household, (2 presence of children, (3 low economic status, (4 residing in urban areas, (5 owning livestock, (6 originating from areas with rabies interventions and (7 having purchased a dog. The majority of dog-owning respondents were willing to contribute no more than US$0.31 towards veterinary services.We identified important knowledge gaps related to, and factors influencing the prevention and control of rabies in Tanzania. Increasing knowledge regarding wound washing, seeking post-exposure prophylaxis and the need to vaccinate dogs are likely to result in more effective prevention of rabies; however, greater engagement of the veterinary and medical sectors is also needed to ensure the availability of preventative services.

  13. Attitude Determination and Control Subsystem (ADCS) Preparations for the EPOXI Flyby of Comet Haley 2

    Science.gov (United States)

    Luna, Michael E.; Collins, Stephen M.

    2011-01-01

    On November 4, 2010 the already "in-flight" Deep Impact spacecraft flew within 700km of comet 103P/Hartley 2 as part of its extended mission EPOXI, the 5th time to date any spacecraft visited a comet. In 2005, the spacecraft had previously imaged a probe impact comet Tempel 1. The EPOXI flyby marked the first time in history that two comets were explored with the same instruments on a re-used spacecraft-with hardware and software originally designed and optimized for a different mission. This made the function of the attitude determination and control subsystem (ADCS) critical to the successful execution of the EPOXI flyby. As part of the spacecraft team preparations, the ADCS team had to perform thorough sequence reviews, key spacecraft activities and onboard calibrations. These activities included: review of background sequences for the initial conditions vector, sun sensor coefficients, and reaction wheel assembly (RWA) de-saturations; design and execution of 10 trajectory correction maneuvers; science calibration of the two telescope instruments; a flight demonstration of the fastest turns conducted by the spacecraft between Earth and comet point; and assessment of RWA health (given RWA problems on other spacecraft).

  14. Attitude Determination and Control Subsystem (ADCS) Preparations for the EPOXI Flyby of Comet Hartley 2

    Science.gov (United States)

    Luna, Michael E.; Collins, Steven M.

    2011-01-01

    On November 4, 2010 the former "Deep Impact" spacecraft, renamed "EPOXI" for its extended mission, flew within 700km of comet 103P/Hartley 2. In July 2005, the spacecraft had previously imaged a probe impact of comet Tempel 1. The EPOXI flyby was the fifth close encounter of a spacecraft with a comet nucleus and marked the first time in history that two comet nuclei were imaged at close range with the same suite of onboard science instruments. This challenging objective made the function of the attitude determination and control subsystem (ADCS) critical to the successful execution of the EPOXI flyby.As part of the spacecraft flyby preparations, the ADCS operations team had to perform meticulous sequence reviews, implement complex spacecraft engineering and science activities and perform numerous onboard calibrations. ADCS contributions included design and execution of 10 trajectory correction maneuvers, the science calibration of the two telescopic instruments, an in-flight demonstration of high-rate turns between Earth and comet point, and an ongoing assessment of reaction wheel health. The ADCS team was also responsible for command sequences that included updates to the onboard ephemeris and sun sensor coefficients and implementation of reaction wheel assembly (RWA) de-saturations.

  15. Knowledge and attitudes of cattle owners regarding trypanosomosis control in tsetse-infested areas of Uganda

    Directory of Open Access Journals (Sweden)

    J.W. Magona

    2004-06-01

    Full Text Available Apilot survey using a structured questionnaire was conducted in Tororo and Busia districts of Uganda on the knowledge and attitudes of cattle owners regarding tsetse fly and trypanosomosis control, in order to understand factors that hindered their full participation. A total of 81 cattle owners was randomly selected and interviewed, of which 92.5 % were aware of tsetse flies and trypanosomosis and 87.6%recognised animal trypanosomosis as a problem in the area. Most cattle owners were aware of tsetse fly trapping (76.5 %, isometamidium chloride use (55.5 %, diminazene aceturate use (48 % and pour-on applications (18.5 %. However, knowledge did not coincide with the application of control measures. Despite the widespread awareness, tsetse fly trapping and pour-on applications were used by only a small percentage of cattle owners (7.5 % applied tsetse fly trapping while 76.5%were aware of it; 1.2%applied pour-oninsecticides while 18.5%were aware of them. Differences between awareness and application were highly significant for tsetse fly trapping (c2=67.8, d.f.=1, P<0.001 and pour-on applications (c2=10.8, d.f.=1, P<0.05, but not for isometamidium chloride use (c2 = 0.08, d.f. = 1, P = 0.77 and diminazene aceturate use (c2 = 0.00, d.f. = 1, P = 1.00. Most cattle owners (97.5 % were willing to participate in future control programmes, but preferred participating on a group basis (85.2 % rather than individually (14.8 %. The 4 most favoured control options in order of importance were: fly traps supplied by the government and maintained by cattle owners; contribution of labour by cattle owners for trap deployment; self-financing of trypanocidal drugs and self-financing of pour-on insecticide. The control options that should be selected in order to elicit full participation by cattle owners are discussed.

  16. Guidance and Control of Position and Attitude for Rendezvous and Dock/Berthing with a Noncooperative/Target Spacecraft

    Directory of Open Access Journals (Sweden)

    Gilberto Arantes

    2014-01-01

    Full Text Available Noncooperative target spacecrafts are those assets in orbit that cannot convey any information about their states (position, attitude, and velocities or facilitate rendezvous and docking/berthing (RVD/B process. Designing a guidance, navigation, and control (GNC module for the chaser in a RVD/B mission with noncooperative target should be inevitably solved for on-orbit servicing technologies. The proximity operations and the guidance for achieving rendezvous problems are addressed in this paper. The out-of-plane maneuvers of proximity operations are explored with distinct subphases, including a chaser far approach in the target’s orbit to the first hold point and a closer approach to the final berthing location. Accordingly, guidance solutions are chosen for each subphase from the standard Hill based Closhessy-Willtshire (CW solution, elliptical fly-around, and Glideslope algorithms. The control is based on a linear quadratic regulator approach (LQR. At the final berthing location, attitude tracker based on a proportional derivative (PD form is tested to synchronize the chaser and target attitudes. The paper analyzes the performance of both controllers in terms of the tracking ability and the robustness. Finally, it prescribes any restrictions that may be imposed on the guidance during any subphase which can help to improve the controllers tracking ability.

  17. Integrated Power and Attitude Control System Demonstrated With Flywheels G2 and D1

    Science.gov (United States)

    Jansen, Ralph H.

    2005-01-01

    On September 14, 2004, NASA Glenn Research Center's Flywheel Development Team experimentally demonstrated a full-power, high-speed, two-flywheel system, simultaneously regulating a power bus and providing a commanded output torque. Operation- and power-mode transitions were demonstrated up to 2000 W in charge and 1100 W in discharge, while the output torque was simultaneously regulated between plus or minus 0.8 N-m. The G2 and D1 flywheels--magnetically levitated carbon-fiber wheels with permanent magnet motors--were used for the experiment. The units were mounted on an air bearing table in Glenn's High Energy Flywheel Facility. The operational speed range for these tests was between 20,000 and 60,000 rpm. The bus voltage was regulated at 125 V during charge and discharge, and charge-discharge and discharge-charge transitions were demonstrated by changing the amount of power that the power supply provided between 300 and 0 W. In a satellite system, this would be the equivalent of changing the amount of energy that the solar array provides to the spacecraft. In addition to regulating the bus voltage, we simultaneously controlled the net torque produced by the two flywheel modules. Both modules were mounted on an air table that was restrained by a load cell. The load cell measured the force on the table, and the torque produced by the two flywheels on the table could be calculated from that measurement. This method was used to measure the torque produced by the modules, yielding net torques from -0.8 to 0.8 N-m. This was the first Glenn demonstration of the Integrated Power and Attitude Control System (IPACS) at high power levels and speeds.

  18. Use of hormonal contraceptives to control menstrual bleeding: attitudes and practice of Brazilian gynecologists

    Directory of Open Access Journals (Sweden)

    Makuch MY

    2013-11-01

    Full Text Available María Y Makuch,1 Maria José D Osis,1 Karla Simonia de Pádua,1,2 Luis Bahamondes3 1Center for Research in Reproductive Health (CEMICAMP, 2Prof Dr José Aristodemo Pinotti Women's Hospital, University of Campinas, 3Department of Obstetrics and Gynaecology, School of Medical Sciences, University of Campinas, and National Institute of Hormones and Women's Health, Campinas, São Paulo, Brazil Background: The purpose of this study was to assess the attitudes and prescribing practices of Brazilian obstetricians and gynecologists regarding use of contraceptive methods to interfere with menstruation and/or induce amenorrhea. Methods: We undertook a nationwide survey of Brazilian obstetricians and gynecologists selected using a computer-generated randomization system. Participants completed a questionnaire on prescription of contraceptives and extended/continuous regimens of combined oral contraceptives (COCs. Results: In total, 79.2% of Brazilian obstetricians and gynecologists reported that 20%–40% of their patients consulted them for menstrual-related complaints and 26%–34% of the gynecologists reported that 21%–40% of their patients consulted them for reduction in the intensity, frequency, and/or duration of menstrual bleeding. Overall, 93% stated that medically induced amenorrhea represents no risk to women's health and 82.5% said that they prescribed contraceptives to control menstruation or induce amenorrhea. The contraceptives most commonly prescribed were extended-cycle 24/4 or 26/2 COC regimens and the levonorgestrel-releasing intrauterine system. Poisson regression analysis showed that Brazilian obstetricians and gynecologists prescribing contraceptives to control menstruation or induce amenorrhea consider extended-use or continuous-use COC regimens to be effective for both indications (prevalence ratio 1.23 [95% confidence interval 1.09–1.40] and prevalence ratio 1.28 [95% confidence interval 1.13–1.46], respectively. They also

  19. Development of common metrics for donation attitude, subjective norm, perceived behavioral control, and intention for the blood donation context.

    Science.gov (United States)

    France, Janis L; Kowalsky, Jennifer M; France, Christopher R; McGlone, Sarah T; Himawan, Lina K; Kessler, Debra A; Shaz, Beth H

    2014-03-01

    The Theory of Planned Behavior has been widely used in blood donation research, but the lack of uniform, psychometrically sound measures makes it difficult to draw firm conclusions or compare results across studies. Accordingly, the goal of this study was to develop such measures of donation attitude, subjective norm, perceived behavioral control, and intention. Exploratory and confirmatory factor analyses (CFAs) were conducted on survey responses collected from college students (n = 1080). The resulting scales were then administered to an independent sample of experienced donors (n = 433) for additional CFAs and to test whether the Theory of Planned Behavior model provided a good fit to the data. CFAs conducted on both samples support the use of six-item scales, with two factors each, to measure donation attitude, subjective norm, and perceived behavioral control and a single-factor three-item scale to measure donation intention. Further, structural equation modeling of these measures revealed that the Theory of Planned Behavior provided a strong fit to the data (comparative fit index, 0.976; root mean square error of approximation, 0.041; standardized root mean square residual, 0.055) and accounted for 73.7% of the variance in donation intention. The present findings confirm the applicability of the Theory of Planned Behavior to the blood donation context and more importantly provide psychometric support for the future use of four brief measures of donation attitude, subjective norm, perceived behavioral control, and intention. © 2013 American Association of Blood Banks.

  20. Attitudes, subjective norms and perception of behavioural control as predictors of sun-related behaviour in Swedish adults.

    Science.gov (United States)

    Bränström, Richard; Ullén, Henrik; Brandberg, Yvonne

    2004-11-01

    Exposure to ultraviolet (UV) radiation is the major preventable cause of skin cancer. The aim of this study was to investigate the explanatory value of attitudes, subjective norms and perceived behavioural control on behaviours related to UV exposure. A random population-based sample (n = 1752, 18-37 years of age) in the Stockholm County, Sweden, answered a questionnaire with items on sun related behaviours and beliefs. The items concerned issues influenced by the Theory of Planned Behaviour, that is, attitudes, subjective norms and perceived behavioural control. Logistic regression analysis was used to examine the associations between behaviours and beliefs. Positive attitudes towards being tanned and being in the sun were both strongly associated with time spent in the sun, intentional tanning, sunbed use, going on vacation to a sunny resort, intention to decrease sunbathing and use of protection against the sun. Perceiving sunbathing as risky was associated with using different ways to protect and intending to reduce sun exposure. Having people around oneself who frequently sunbathe was related to intentional tanning and vacations to sunny resorts. Finally, perceived behavioural control was associated with use of sunscreen and use of other ways to protect from the sun among women. The study identified factors on which primary preventive interventions towards decreasing sun exposure should be focused.

  1. Impact of an Oral Health Education Workshop on Parents’ Oral Health Knowledge, Attitude, and Perceived Behavioral Control among African Immigrants

    Directory of Open Access Journals (Sweden)

    Maryam Amin

    2014-01-01

    Full Text Available Purpose. To evaluate the impact of an educational workshop on parental knowledge, attitude, and perceived behavioral control regarding their child’s oral health. Materials and Methods. A one-time oral health education workshop including audio/visual and hands-on components was conducted by a trained dentist and bilingual community workers in community locations. Participants were African parents of children who had lived in Canada for less than ten years. The impact of the workshop was evaluated by a questionnaire developed based on the theory of planned behavior. Results. A total of 105 parents participated in this study. Participants were mainly mothers (mean age 35.03±5.4 years who came to Canada as refugee (77.1% and had below high school education (70%. Paired t-test showed a significant difference in participants’ knowledge of caries, preventive measures, and benefits of regular dental visits after the workshop (P value<0.05. A significant improvement was also found in parental attitudes toward preventive measures and their perceived behavioral control (P<0.05. Parents’ intention to take their child to a dentist within six months significantly altered after the workshop (P value<0.05. Conclusions. A one-time hands-on training was effective in improving parental knowledge, attitude, perceived behavioral control, and intention with respect to their child’s oral health and preventive dental visits in African immigrants.

  2. Application of MAVEN Accelerometer and Attitude Control Data to Mars Atmospheric Characterization

    Science.gov (United States)

    Zurek, Richard W.; Tolson, Robert H.; Baird, Darren; Johnson, Mark Z.; Bougher, Stephen W.

    2015-12-01

    The structure of the upper atmosphere of Mars (above ˜100 km) has been probed in situ mainly using spacecraft accelerometers during the aerobraking phases of 3 Mars orbiters. In a similar manner, the Mars Atmosphere and Volatile Evolution (MAVEN) Accelerometer Experiment (ACC) will also use atmospheric drag accelerations sensed by inertial measurement units (IMU) onboard the spacecraft to recover atmospheric density along the orbiter path. These densities are used to estimate hydrostatic `vertical' density and temperature profiles, along track and altitudinal density waves, and latitudinal and longitudinal density variations. The IMU accelerometer signal-to-noise should permit profile reconstructions from spacecraft periapsis, nominally at 150 km altitude, to ˜170 km, an altitude range nominally spanning densities of 0.05-0.15 kg/km3. However, in situ measurements over a much greater altitude range, down to ˜125 km (reaching densities of ˜2-3.5 kg/km3), can be made during each of five week-long "Deep Dip" (DD) campaigns, and these are the prime focus of the Accelerometer Experiment. Judicious choice of the timing of these Deep-Dip campaigns during the MAVEN periapsis progression through local time, latitude and longitude in both hemispheres and in different seasons will add significantly to the existing data base of lower thermospheric densities. Other IMU and attitude control data may be used to estimate torques in order to improve the atmospheric density analysis, especially in the higher altitudes of the nominal science orbit, and, more challengingly, to estimate cross-track winds during the Deep-Dips.

  3. Acoustic-Modal Testing of the Ares I Launch Abort System Attitude Control Motor Valve

    Science.gov (United States)

    Davis, R. Benjamin; Fischbach, Sean R.

    2010-01-01

    The Attitude Control Motor (ACM) is being developed for use in the Launch Abort System (LAS) of NASA's Ares I launch vehicle. The ACM consists of a small solid rocket motor and eight actuated pintle valves that directionally allocate.thrust_- 1t.has-been- predicted-that significant unsteady. pressure.fluctuations.will.exist. inside the-valves during operation. The dominant frequencies of these oscillations correspond to the lowest several acoustic natural frequencies of the individual valves. An acoustic finite element model of the fluid volume inside the valve has been critical to the prediction of these frequencies and their associated mode shapes. This work describes an effort to experimentally validate the acoustic finite model of the valve with an acoustic modal test. The modal test involved instrumenting a flight-like valve with six microphones and then exciting the enclosed air with a loudspeaker. The loudspeaker was configured to deliver broadband noise at relatively high sound pressure levels. The aquired microphone signals were post-processed and compared to results generated from the acoustic finite element model. Initial comparisons between the test data and the model results revealed that additional model refinement was necessary. Specifically, the model was updated to implement a complex impedance boundary condition at the entrance to the valve supply tube. This boundary condition models the frequency-dependent impedance that an acoustic wave will encounter as it reaches the end of the supply tube. Upon invoking this boundary condition, significantly improved agreement between the test data and the model was realized.

  4. Auto Code Generation for Simulink-Based Attitude Determination Control System

    Science.gov (United States)

    MolinaFraticelli, Jose Carlos

    2012-01-01

    This paper details the work done to auto generate C code from a Simulink-Based Attitude Determination Control System (ADCS) to be used in target platforms. NASA Marshall Engineers have developed an ADCS Simulink simulation to be used as a component for the flight software of a satellite. This generated code can be used for carrying out Hardware in the loop testing of components for a satellite in a convenient manner with easily tunable parameters. Due to the nature of the embedded hardware components such as microcontrollers, this simulation code cannot be used directly, as it is, on the target platform and must first be converted into C code; this process is known as auto code generation. In order to generate C code from this simulation; it must be modified to follow specific standards set in place by the auto code generation process. Some of these modifications include changing certain simulation models into their atomic representations which can bring new complications into the simulation. The execution order of these models can change based on these modifications. Great care must be taken in order to maintain a working simulation that can also be used for auto code generation. After modifying the ADCS simulation for the auto code generation process, it is shown that the difference between the output data of the former and that of the latter is between acceptable bounds. Thus, it can be said that the process is a success since all the output requirements are met. Based on these results, it can be argued that this generated C code can be effectively used by any desired platform as long as it follows the specific memory requirements established in the Simulink Model.

  5. Robust Fault-Tolerant Control for Satellite Attitude Stabilization Based on Active Disturbance Rejection Approach with Artificial Bee Colony Algorithm

    Directory of Open Access Journals (Sweden)

    Fei Song

    2014-01-01

    Full Text Available This paper proposed a robust fault-tolerant control algorithm for satellite stabilization based on active disturbance rejection approach with artificial bee colony algorithm. The actuating mechanism of attitude control system consists of three working reaction flywheels and one spare reaction flywheel. The speed measurement of reaction flywheel is adopted for fault detection. If any reaction flywheel fault is detected, the corresponding fault flywheel is isolated and the spare reaction flywheel is activated to counteract the fault effect and ensure that the satellite is working safely and reliably. The active disturbance rejection approach is employed to design the controller, which handles input information with tracking differentiator, estimates system uncertainties with extended state observer, and generates control variables by state feedback and compensation. The designed active disturbance rejection controller is robust to both internal dynamics and external disturbances. The bandwidth parameter of extended state observer is optimized by the artificial bee colony algorithm so as to improve the performance of attitude control system. A series of simulation experiment results demonstrate the performance superiorities of the proposed robust fault-tolerant control algorithm.

  6. Design of Satellite Attitude Control Algorithm Based on the SDRE Method Using Gas Jets and Reaction Wheels

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    Luiz C. G. de Souza

    2013-01-01

    Full Text Available An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

  7. Effects of a Cell Phone Use Education Program on Knowledge, Attitude, Self-efficacy, and Self-control of Cell Phone Use in Elementary School Students

    National Research Council Canada - National Science Library

    Koo, Hyun-Young

    2012-01-01

    This study was done to develop an education program on cell phone use for elementary school students, and examine its effects on their knowledge, attitude, self-efficacy, and self-control in cell phone use...

  8. Survey on attitudes toward HIV-infected individuals and infection control practices among dentists in Mexico City.

    Science.gov (United States)

    Maupomé, G; Acosta-Gío, E; Borges-Yáñez, S A; Díez-de-Bonilla, F J

    2000-02-01

    The teaching of infection control is gradually being introduced at dental schools in Mexico. However, most practicing dentists have limited access to current infection control standards. Deficiencies of knowledge with regard to blood-borne pathogens such as HIV and hepatitis B virus may influence attitudes toward infected individuals and reduce compliance with infection control recommendations. The purpose of this study was to assess (1) attitudes toward HIV-infected patients and hepatitis B virus-infected patients and (2) infection control knowledge and practices among dental practitioners in Mexico City. A total of 196 dentists were interviewed by means of a questionnaire with Likert-type scales and open-ended questions (response rate, 86.1%). Most respondents had no previous social or professional contact with HIV-positive individuals. Nine percent indicated that they had knowingly treated HIV-positive patients. Perceived professional and moral obligations to treat HIV-positive patients were high. Thirty-five percent of the respondents perceived the risk of HIV infection as "considerable" to "very strong." The risk of hepatitis B infection was considered significantly higher than the risk of HIV infection (P personal protective equipment was high. Most respondents used dry heat sterilization. The principal disinfectants used were quaternary ammonium compounds, bleach, and glutaraldehyde. Fifty-four percent of the respondents acknowledged that clinical precautions reduced occupational risks. This survey revealed contradictory attitudes toward HIV-positive individuals and limited understanding of infection control recommendations. Educational and regulatory efforts are needed to promote better adherence to current infection control standards.

  9. Relationship of credit attitude and debt to self-esteem and locus of control in college-age consumers.

    Science.gov (United States)

    Pinto, Mary Beth; Mansfield, Phylis M; Parente, Diane H

    2004-06-01

    College-age consumers are one of the groups most highly targeted by credit card marketers. While some college students use their credit cards wisely, others are unable to control their spending. The objective of this study was to investigate differences in attitude toward credit cards and the psychological factors of self-esteem and locus of control among college students who possess one or more credit cards. Attitude was operationalized to include three underlying components: cognitive, affective, and behavioral. We separated credit users into subcategories based on amount of installment debt. Convenience users were defined as those consumers who paid the credit-card balance in full each month. Installment users were classified as consumers who carried a balance month-to-month. Convenience users were compared to mild and heavy installment users to assess significance of differences in attitudinal and psychological factors. There were no significant differences in the psychological factors across the credit-card user groups. In addition, there was a statistically significant difference on each of the attitude components (knowledge/beliefs, affect, and behavior) across user groups; convenience users, mild installment, and heavy installment users.

  10. Perceived behavioural control, subjective norms, attitudes and intention to use condom: a longitudinal cross-lagged design.

    Science.gov (United States)

    Prati, Gabriele; Mazzoni, Davide; Zani, Bruna

    2014-01-01

    Based on the Theory of Planned Behaviour (TPB), the purpose of this investigation was to examine the directionality of the association among condom use, intention, attitudes, subjective norms and perceived behavioural control. The present study investigated the nature of these relationships using a longitudinal cross-lagged design applied to data from a cohort of 958 randomly selected Italian adults. Using structural equation modelling, two cross-lagged panel analyses revealed reciprocal relationships between intention and attitudes and between intention and condom use. Contrary to expectations, baseline subjective norms and perceived behavioural control did not predict subsequent intention to use condom when controlled for the autoregressive effect of intention at T1 on the same variable at T2. Also, perceived behavioural control at T1 did not influence condom use at T2 after controlling for the effect of baseline intention. The possibility of reciprocity was also tested for all relations and significant results were found. The moderation effect of perceived behavioural control on the relationship between intention and condom use was not significant. The differences in age, gender and partnership status were taken into account in the analyses.

  11. ATTITUDE CONTROL SYSTEM DESIGN FOR A RIGID-FLEXIBLE SATELLITE USING THE H-INFINITY METHOD WITH PARAMETRIC UNCERTAINTY

    OpenAIRE

    Souza, Alain Giacobini de; Souza, Luiz Carlos Gadelha de

    2017-01-01

    This paper presents the Attitude Control System (ACS) design for a rigid-flexible satellite with two vibrations mode, using the H infinity method considering the parametric uncertainty over the mass matrix. Usually the mathematic model obtained from the linearization and/or reduction of the rigid flexible model loses information about the flexible dynamical behavior and introduces some uncertainty. As a result, the ACS performance can be degraded when controlling large angle maneuvers. One wa...

  12. Longitudinal associations of intimate partner violence attitudes and perpetration: Dyadic couples data from a randomized controlled trial in rural India.

    Science.gov (United States)

    Shakya, Holly B; Fleming, Paul; Saggurti, Niranjan; Donta, Balaiah; Silverman, Jay; Raj, Anita

    2017-04-01

    We conducted longitudinal analyses examining the associations between intimate partner violence (IPV) attitudes and women's reported IPV in couples (N = 762) using 3 waves of data from a randomized controlled trial in Maharashtra, India. We found that, between Waves 1 and 2, men's and women's acceptance of IPV in the overall population decreased significantly while reports of IPV increased. These changes, we hypothesize, are evidence of an exogenous shock, possibly a high profile rape in Delhi in December 2012, that may have impacted the entire population. Cross-sectional associations between men's attitudes towards IPV and reported IPV were not significant in Wave 1, while positively and significantly associated in Waves 2 and 3. Longitudinal analysis showed that reduction in men's acceptance of IPV between Waves 1 and 2 was associated with a lower likelihood of reported IPV in Wave 3. Women's Wave 1 acceptance of IPV was positively associated with reported IPV in the Wave 1 cross-sectional analysis, while Wave 2 and Wave 3 measures of IPV acceptance were negatively associated with reported IPV in Waves 2 and 3 respectively. Longitudinal analyses of the change in women's attitudes towards IPV from Wave 1 to 2 and reported IPV in Wave 3 were insignificant. However, When women first reported IPV in Waves 2 or 3 they were less likely to report acceptance of IPV in that same wave. Findings suggest that changes in husbands' IPV acceptance is predictive of subsequent IPV, while newly experienced IPV predicts decreased IPV acceptance for women. Wave 2 and Wave 3 results were significant for the control group only, evidence that the intervention affected those associations, potentially changing attitudes more quickly than behavior. We recommend interventions that expose community opposition to IPV as a new social norm, and analysis of how the 2012 Delhi rape case may have affected these norms. Copyright © 2017. Published by Elsevier Ltd.

  13. Helicopter gust alleviation, attitude stabilization, and vibration alleviation using individual-blade-control through a conventional swash plate

    Science.gov (United States)

    Ham, N. D.

    1985-01-01

    The novel active control system presented for helicopter rotor aerodynamic and aeroelastic problems involves the individual control of each blade in the rotating frame over a wide range of frequencies (up to the sixth harmonic of rotor speed). This Individual Blade Control (IBC) system controls blade pitch by means of broadband electrohydraulic actuators attached to the swash plate (in the case of three blades) or individually to each blade, using acceleratometer signals to furnish control commands to the actuators. Attention is given to IBC's application to blade lag, flapping, and bending dynamics. It is shown that gust alleviation, attitude stabilization, vibration alleviation, and air/ground resonance suppression, are all achievable with a conventional helicopter swash plate.

  14. Differentiating the effects of maternal and peer encouragement to diet on child weight control attitudes and behaviors.

    Science.gov (United States)

    Armstrong, Bridget; Janicke, David M

    2012-12-01

    Obese and overweight youth are more at risk for engaging in frequent dieting, unhealthy weight control behaviors and report more body dissatisfaction than their normal weight peers. Previous research has indicated that peer and maternal encouragement to diet is predictive of unhealthy weight related behaviors and attitudes. The current study aims to examine if maternal and peer encouragement to diet equally mediate the relationship between youth BMI z-score and (a) unhealthy weight control behaviors, (b) diet frequency and (c) body dissatisfaction in a sample of racially diverse boys and girls. Participants were 94 children/adolescents between the ages of 8-17. Results were stratified by gender. Three bootstrapped multiple mediation models were conducted to examine each outcome variable. Results indicated that maternal encouragement to diet mediated the relationships predicting unhealthy weight control and diet frequency for girls, but not for boys. Peer encouragement to diet significantly mediated the relationship predicting unhealthy weight control behaviors, with increased peer encouragement associated with fewer unhealthy weight control behaviors for girls. Peer encouragement to diet was not a significant mediator for any of the outcomes for boys. Results suggest that maternal encouragement to diet may play a larger role than peer encouragement to diet in predicting unhealthy weight attitudes and behaviors for girls. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. BReastfeeding Attitude and Volume Optimization (BRAVO) trial : Study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Savitri, Ary I.; Idris, Nikmah S; Indawati, Wahyuni; Saldi, Siti Rizny F; Amelia, Dwirani; Baharuddin, Mohammad; Sastroasmoro, Sudigdo; Grobbee, Diederick E.; Uiterwaal, Cuno S P M

    2016-01-01

    Background: A growing body of evidence shows the short-term benefits of breastfeeding, which include protection against infections, allergies, and lung diseases. However, evidence on the long-term benefits of breastfeeding is scarce and often conflicting. The BReastfeeding Attitude and Volume

  16. Near Real-Time Closed-Loop Optimal Control Feedback for Spacecraft Attitude Maneuvers

    Science.gov (United States)

    2009-03-01

    slightly shorter path due to the Sagnac effect. A sensor also located at either end of the fiber optic coil is characterized to measure the effects...A. Bosse, and S. Fisher. A Integrated GPS / Gyro / Smart Structures Architecture for Attitude Determination and Baseline Metrology . In Proceedings of

  17. Attitudes toward euthanasia and physician-assisted suicide: a study of the multivariate effects of healthcare training, patient characteristics, religion and locus of control.

    Science.gov (United States)

    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, peuthanasia 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.

  18. Attitudes, norms and controls influencing lifestyle risk factor management in general practice

    Directory of Open Access Journals (Sweden)

    McKenzie Suzanne H

    2009-08-01

    patient's motivation, and cost and accessibility of services to patients. Conclusion General practitioner attitudes, normative influences from both patients and the profession, and perceived external control factors (time, cost, availability and practice capacity all influence management of behavioural risk factors. Provider education, community awareness raising, support and capacity building may improve the uptake of lifestyle modification interventions.

  19. [Dietary habits, attitudes toward weight control, and subjective symptoms of fatigue in young women in Japan].

    Science.gov (United States)

    Osako, Mai; Takayama, Tomoko; Kira, Shohei

    2005-05-01

    This paper describes dietary habits and attitudes toward body weight control of college women in Japan and examines their relationships with subjective symptoms of fatigue. We also discuss strategies to promote better diets among young adults. Self-reported questionnaires were distributed to 286 young women aged 18 to 25 years; 275 of these were analyzed. The study found that more than half of the women were concerned about nutritional balance and calories. Yet thirty percent ate "a single-item meal (i.e., bread, rice bowl, noodles) two or more times a day," while roughly one half skipped breakfast "sometimes" or "always." A majority ate vegetables "almost never" and consumed instant foods, confectionery, or sugary drinks "almost daily." Subjective symptoms of fatigue were significantly correlated with a higher frequency of irregular meal-taking, single-item meals, between-meal snacking, missed breakfasts, non-vegetable diets, non-fruit diets, and instant foods and confectionery. About sixty percent of the women in the study considered their bodies to be "slightly fat or overweight" while 79.5% indicated a desire to "lose weight". On average, the participants' ideal BMI was 18.7 (+/- 1.2) while the ideal body weight was 47.2 (+/- 4.1) kg, approximately 4 kg under actual average body weight. Subjective symptoms of fatigue were stronger among women who considered themselves "slightly fat or overweight". Likewise, symptoms were stronger to the extent that a participant's ideal BMI was below her actual BMI. Many women in this study desired to lose weight although they were not overweight by objective measures. The study suggests that subjective symptoms of fatigue are not the result of individual dietary habits, but rather of a lifestyle that reach to series of dietary habits connected to subjective symptoms of fatigue. The study also confirms the importance both of encouraging young women not just to eat well but to lead lifestyles in which they do not skip meals and

  20. Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor

    Science.gov (United States)

    Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy

    2013-01-01

    Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited

  1. Attitudes, norms and controls influencing lifestyle risk factor management in general practice.

    Science.gov (United States)

    Ampt, Amanda J; Amoroso, Cheryl; Harris, Mark F; McKenzie, Suzanne H; Rose, Vanessa K; Taggart, Jane R

    2009-08-26

    services to patients. General practitioner attitudes, normative influences from both patients and the profession, and perceived external control factors (time, cost, availability and practice capacity) all influence management of behavioural risk factors. Provider education, community awareness raising, support and capacity building may improve the uptake of lifestyle modification interventions.

  2. Knowledge, awareness, and attitude regarding infection prevention and control among medical students: a call for educational intervention.

    Science.gov (United States)

    Ibrahim, Awab Ali; Elshafie, Sittana Shamseldin

    2016-01-01

    Medical students can be exposed to serious health care-associated infections, if they are not following infection prevention and control (IPC) measures. There is limited information regarding the knowledge, awareness, and practices of medical students regarding IPC and the educational approaches used to teach them these practices. To evaluate the knowledge, awareness, and attitude of medical students toward IPC guidelines, and the learning approaches to help improve their knowledge. A cross-sectional, interview-based survey included 73 medical students from Weill Cornell Medical College, Qatar. Students completed a questionnaire concerning awareness, knowledge, and attitude regarding IPC practices. Students' knowledge was assessed by their correct answers to the survey questions. A total of 48.44% of the respondents were aware of standard isolation precautions, 61.90% were satisfied with their training in IPC, 66.13% were exposed to hand hygiene training, while 85.48% had sufficient knowledge about hand hygiene and practiced it on a routine basis, but only 33.87% knew the duration of the hand hygiene procedure. Knowledge, attitude, and awareness of IPC measures among Weill Cornell Medical Students in Qatar were found to be inadequate. Multifaceted training programs may have to target newly graduated medical practitioners or the training has to be included in the graduate medical curriculum to enable them to adopt and adhere to IPC guidelines.

  3. Knowledge Attitude and Practices Toward Lassa Fever Control and Prevention Among Residents of Ile-Ife, Southwest Nigeria.

    Science.gov (United States)

    Olowookere, S A; Adegbenro, C A; Idowu, A; Omisore, A G; Shabi, O M; Ikem, U R; Ekwere, G A; Oderinde, I F

    2017-01-01

    Lassa fever had been reported as a cause of death especially in endemic parts of Nigeria. This study assessed the knowledge, attitude, and practices toward Lassa fever control and prevention among residents of Ile-Ife, southwest Nigeria. Descriptive cross-sectional study was conducted among consenting randomly selected adults using an interviewer administered questionnaire. Data were analyzed using descriptive and inferential statistics. A total of 400 questionnaires with completed data were analyzed (response rate 96%). Majority, 207 (51.8%), were males while 193 (48.2%) were females. Most, 234 (58.5%), had tertiary education while 148 (37%) had secondary education. Fifty-nine percent had heard of Lassa fever with radio as their major source of information. About 76% had inadequate knowledge, 54% had negative attitude while 51% had poor practice toward Lassa fever. Determinants of knowledge of Lassa fever include having higher education (Adjusted Odd Ratio (AOR) = 11.49, 95% CI [3.10, 42.69], p = .0001), being in civil service (AOR = 0.22, 95% CI [0.09, 0.51], p = .01), and earning higher income (AOR = 4.23, 95% CI [2.61, 6.84], p = .0001). In conclusion, the knowledge, attitude, as well as preventive practices to Lassa fever were poor. It is necessary to increase public education and improve hygienic practices.

  4. Integration of a Motion Capture System into a Spacecraft Simulator for Real-Time Attitude Control

    Science.gov (United States)

    2016-08-16

    DISTRIBUTION A. Approved for public release: distribution unlimited. Integration of a Motion Capture System into a Spacecraft Simulator for Real-Time...integrated with a Phase- Space Impulse X2 motion capture system. This system calculates the testbed’s inertial attitude, which can be used to simulate various...generate measurements via another source. To that end, a PhaseSpace Impulse X2 motion capture system has been integrated with the ACSPG and a wireless

  5. Quality Control in Survey Design: Evaluating a Survey of Educators’ Attitudes Concerning Differentiated Compensation

    OpenAIRE

    Kelly D Bradley; Michael Peabody; Sampson, Shannon O.

    2016-01-01

    This study utilized the Rasch model to assess the quality of a survey instrument designed to measure attitudes of administrators and teachers concerning a differentiated teacher compensation program piloted in Kentucky.  Researchers addressing potentially contentious issues should ensure their methods stand up to rigorous criticism.  The results indicate that the rating scale does not function as expected, with items being too easy to endorse.  Future iterations of this survey should be revis...

  6. Attitudes of Internet users in Poland toward the new Polish Tobacco Control Law and the EU Tobacco Products Directive – types of arguments and semantic maps portray

    Directory of Open Access Journals (Sweden)

    Krzysztof Przewoźniak

    2017-05-01

    Qualitative analysis of attitudes toward tobacco control policy is a key for in-depth understanding why people oppose or are in favor of tobacco control policy and its results can help in effective enforcement of the new tobacco control law in Poland.

  7. Predicting participation in group parenting education in an Australian sample: the role of attitudes, norms, and control factors.

    Science.gov (United States)

    White, Katherine M; Wellington, Larne

    2009-03-01

    We examined the theory of planned behavior (TPB) in predicting intentions to participate in group parenting education. One hundred and seventy-six parents (138 mothers and 38 fathers) with a child under 12 years completed TPB items assessing attitude, subjective norms, perceived behavioral control (PBC), and two additional social influence variables (self-identity and group norm). Regression analyses supported the TPB predictors of participation intentions with self-identity and group norm also significantly predicting intentions. Editors' Strategic Implications: these findings provide preliminary support for the TPB, in conjunction with additional sources of social influence, as a predictive model for participation in parent education and other prevention programs.

  8. Estimate of the control threshold value in the problem on a time-optimal satellite attitude transition maneuver

    Science.gov (United States)

    Reshmin, S. A.

    2017-01-01

    The time-optimal problem is considered for a nonlinear Lagrangian system with one degree of freedom. The system is controlled by a force bounded in absolute value, and all noncontrol forces are potential.We study the properties of optimal synthesis on the phase cylinder and indicate the conditions under which it has the simplest structure, namely, involves at most one switching for any initial conditions. The approach is used to specify the structure of the well-known solution in the classical problem on the time-optimal satellite attitude transition maneuver in the orbit plane.

  9. Farmer Attitudes and Livestock Disease: Exploring Citizenship Behaviour and Peer Monitoring across Two BVD Control Schemes in the UK.

    Directory of Open Access Journals (Sweden)

    Claire Heffernan

    Full Text Available The eradication of BVD in the UK is technically possible but appears to be socially untenable. The following study explored farmer attitudes to BVD control schemes in relation to advice networks and information sharing, shared aims and goals, motivation and benefits of membership, notions of BVD as a priority disease and attitudes toward regulation. Two concepts from the organisational management literature framed the study: citizenship behaviour where actions of individuals support the collective good (but are not explicitly recognised as such and peer to peer monitoring (where individuals evaluate other's behaviour. Farmers from two BVD control schemes in the UK participated in the study: Orkney Livestock Association BVD Eradication Scheme and Norfolk and Suffolk Cattle Breeders Association BVD Eradication Scheme. In total 162 farmers participated in the research (109 in-scheme and 53 out of scheme. The findings revealed that group helping and information sharing among scheme members was low with a positive BVD status subject to social censure. Peer monitoring in the form of gossip with regard to the animal health status of other farms was high. Interestingly, farmers across both schemes supported greater regulation with regard to animal health, largely due to the mistrust of fellow farmers following voluntary disease control measures. While group cohesiveness varied across the two schemes, without continued financial inducements, longer-term sustainability is questionable.

  10. Chocolate cake. Guilt or celebration? Associations with healthy eating attitudes, perceived behavioural control, intentions and weight-loss.

    Science.gov (United States)

    Kuijer, Roeline G; Boyce, Jessica A

    2014-03-01

    Food and eating are often associated with ambivalent feelings: pleasure and enjoyment, but also worry and guilt. Guilt has the potential to motivate behaviour change, but may also lead to feelings of helplessness and loss of control. This study firstly examined whether a default association of either 'guilt' or 'celebration' with a prototypical forbidden food item (chocolate cake) was related to differences in attitudes, perceived behavioural control, and intentions in relation to healthy eating, and secondly whether the default association was related to weight change over an 18month period (and short term weight-loss in a subsample of participants with a weight-loss goal). This study did not find any evidence for adaptive or motivational properties of guilt. Participants associating chocolate cake with guilt did not report more positive attitudes or stronger intentions to eat healthy than did those associating chocolate cake with celebration. Instead, they reported lower levels of perceived behavioural control over eating and were less successful at maintaining their weight over an 18month period. Participants with a weight-loss goal who associated chocolate cake with guilt were less successful at losing weight over a 3month period compared to those associating chocolate cake with celebration. Copyright © 2014. Published by Elsevier Ltd.

  11. Attitude control system design and on-orbit performance analysis of nano-satellite—“Tian Tuo 1”

    Directory of Open Access Journals (Sweden)

    Ran Dechao

    2014-06-01

    Full Text Available “Tian Tuo 1” (TT-1 nano-satellite is the first single-board nano-satellite that was successfully launched in China. The main objective of TT-1 is technology demonstration and scientific measurements. The satellite carries out the significant exploration of single-board architecture feasibility validation, and it is tailored to the low-cost philosophy by adopting numerous commercial-off-the-shelf (COTS components. The satellite is featured with three-axis stabilization control capability. A pitch bias momentum wheel and three magnetic coils are adopted as control actuators. The sun sensors, magnetometers and a three-axis gyro are employed as the measurement sensors. The quaternion estimator (QUEST and unscented Kalman filter (UKF method are adopted for the nano-satellite attitude determination. On-orbit data received by ground station is conducted to analysis the performance of attitude determination and control system (ADCS. The results show that the design of ADCS for TT-1 is suitable, robust and feasible.

  12. Adaptive Position/Attitude Tracking Control of Aerial Robot With Unknown Inertial Matrix Based on a New Robust Neural Identifier.

    Science.gov (United States)

    Lai, Guanyu; Liu, Zhi; Zhang, Yun; Chen, C L Philip

    2016-01-01

    This paper presents a novel adaptive controller for controlling an autonomous helicopter with unknown inertial matrix to asymptotically track the desired trajectory. To identify the unknown inertial matrix included in the attitude dynamic model, this paper proposes a new structural identifier that differs from those previously proposed in that it additionally contains a neural networks (NNs) mechanism and a robust adaptive mechanism, respectively. Using the NNs to compensate the unknown aerodynamic forces online and the robust adaptive mechanism to cancel the combination of the overlarge NNs compensation error and the external disturbances, the new robust neural identifier exhibits a better identification performance in the complex flight environment. Moreover, an optimized algorithm is included in the NNs mechanism to alleviate the burdensome online computation. By the strict Lyapunov argument, the asymptotic convergence of the inertial matrix identification error, position tracking error, and attitude tracking error to arbitrarily small neighborhood of the origin is proved. The simulation and implementation results are provided to evaluate the performance of the proposed controller.

  13. Farmer Attitudes and Livestock Disease: Exploring Citizenship Behaviour and Peer Monitoring across Two BVD Control Schemes in the UK.

    Science.gov (United States)

    Heffernan, Claire; Azbel-Jackson, Lena; Brownlie, Joe; Gunn, George

    2016-01-01

    The eradication of BVD in the UK is technically possible but appears to be socially untenable. The following study explored farmer attitudes to BVD control schemes in relation to advice networks and information sharing, shared aims and goals, motivation and benefits of membership, notions of BVD as a priority disease and attitudes toward regulation. Two concepts from the organisational management literature framed the study: citizenship behaviour where actions of individuals support the collective good (but are not explicitly recognised as such) and peer to peer monitoring (where individuals evaluate other's behaviour). Farmers from two BVD control schemes in the UK participated in the study: Orkney Livestock Association BVD Eradication Scheme and Norfolk and Suffolk Cattle Breeders Association BVD Eradication Scheme. In total 162 farmers participated in the research (109 in-scheme and 53 out of scheme). The findings revealed that group helping and information sharing among scheme members was low with a positive BVD status subject to social censure. Peer monitoring in the form of gossip with regard to the animal health status of other farms was high. Interestingly, farmers across both schemes supported greater regulation with regard to animal health, largely due to the mistrust of fellow farmers following voluntary disease control measures. While group cohesiveness varied across the two schemes, without continued financial inducements, longer-term sustainability is questionable.

  14. The influence of patient's consciousness regarding high blood pressure and patient's attitude in face of disease controlling medicine intake

    Directory of Open Access Journals (Sweden)

    Maria Aparecida A Moura Strelec

    2003-10-01

    Full Text Available OBJECTIVE: To assess the relation between blood pressure control and the following: the Morisky-Green test, the patient's consciousness regarding high blood pressure, the patient's attitude in face of medicine intake, the patient's attendance at medical consultations, and the subjective physician's judgment. METHODS: We studied 130 hypertensive patients with the following characteristics: 73% females, 60±11 years, 58% married, 70% white, 45% retired, 45% with incomplete elementary schooling, 64% had a familial income of 1 to 3 minimum wages, body mass index of 30±7 kg/m², consciousness regarding the disease for a mean period of 11±9.5 years, and mean treatment duration of 8 ±7 years. RESULTS: Only 35% of the hypertensive individuals had blood pressure under control and a longer duration of treatment (10±7 vs 7±6.5 years; P<0.05. The retiree predominated. The result of the Morisky-Green test did not relate to blood pressure control. In evaluating the attitude in face of medicine intake, the controlled patients achieved significantly higher scores than did the noncontrolled patients (8±1.9 vs 7 ±2, P<0.05. The hypertensive patients had higher levels of consciousness regarding their disease and its treatment, and most (70% patients attended 3 or 4 medical consultations, which did not influence blood pressure control. The physicians attributed significantly higher scores regarding adherence to treatment to controlled patients (6±0.8 vs 5±1.2; P<0.05. CONCLUSION: Consciousness regarding the disease, the Morisky-Green test, and attendance to medical consultations did not influence blood pressure control.

  15. A High Stiffness Boom to Increase the Moment-Arm for a Propulsive Attitude Control System on FalconSAT-3

    OpenAIRE

    Engberg, Brian; Spanjers, Greg; Wegner, Peter; Bromaghim, Daron; Fetchko, Pamela; Sellers, Jerry; Lake, Mark; Tupper, Mike; Harvey, Jeff; Evans, Jon

    2003-01-01

    Small satellite missions requiring attitude control can realize significant mass savings by extending the moment arm of a propulsion-based system. Replacing traditional torque rods and reaction wheels with small thrusters on extendable booms can significantly reduce the mass of the ACS. Small satellite buses pose significant integration challenges when incorporating electric micro-thrusters. Generally these satellites have low power capability and small geometries. This impacts attitude deter...

  16. A Near-Hover Adaptive Attitude Control Strategy of a Ducted Fan Micro Aerial Vehicle with Actuator Dynamics

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-09-01

    Full Text Available The aerodynamic parameters of ducted fan micro aerial vehicles (MAVs are difficult and expensive to precisely measure and are, therefore, not available in most cases. Furthermore, the actuator dynamics with risks of potentially destabilizing the overall system are important but often neglected consideration factors in the control system design of ducted fan MAVs. This paper presents a near-hover adaptive attitude control strategy of a prototype ducted fan MAV with actuator dynamics and without any prior information about the behavior of the MAV. The proposed strategy consists of an online parameter estimation algorithm and an adaptive gain scheduling algorithm, with the former accommodating parametric uncertainties, and the latter approximately eliminating the coupling among axes and guaranteeing the control quality of the MAV. The effectiveness of the proposed strategy is verified numerically and experimentally.

  17. The impact of knowledge and attitudes on adherence to tuberculosis treatment: a case-control study in a Moroccan region

    Science.gov (United States)

    Tachfouti, Nabil; Slama, Katia; Berraho, Mohammed; Nejjari, Chakib

    2012-01-01

    Background Although tuberculosis (TB) care is provided free of charge in Morocco, a high number of patients voluntarily interrupt their treatment before the end. Treatment Default is a major obstacle in the fight against the disease. The purpose of this study was to describe the impact of knowledge and attitudes toward TB on treatment adherence. Methods Case-control study of 290 TB patients (85 defaulters and 205 controls). A defaulter was defined as a TB patient who interrupted treatment for two months or longer. Socio-demographic measurements, knowledge and attitude were collected by face to face anonymous questionnaire. Khi-square test was conducted to examine differences in TB attitudes and knowledge according to treatment adherence. Results The mean age of participants was 31.7 ± 12.0 years. Monthly income was under 2000 MAD (180 €) for 82% of them. Over sixty four percent were illiterate or had a basic educational level. Microbial cause was known by 17.2% respondents; 20.5% among adherent patients versus 9.4% (p=0.02). The fact that the disease is curable was more known by adherent patients: 99.0% versus 88.2% (p < 0.01). Eighty tree per cent of patients had been informed about treatment duration and consequences of not completing treatment: 89.0% among adherent patients versus 69.7% (p<0.001). The main reason evoked for defaulting was the sensation of being cured (72.9% of defaulters). Conclusion This study shows a poor knowledge on TB especially among non adherent patients. This finding justifies the need to incorporate patient's education into current TB case management. PMID:22937192

  18. Sexual and contraceptives attitudes, the locus of health control and self-esteem among higher education students

    Directory of Open Access Journals (Sweden)

    José Manuel da Silva Vilelas Janeiro

    2014-09-01

    Full Text Available Objective: To analyze the relationship between sexual and contraceptive attitudes, the locus of health control and self-esteem among students of a private institution of higher education. Methods: Descriptive and correlational study with a quantitative approach, performed in a higher education school in Lisbon, with 152 students, from the 1st to the 4th year of undergraduate courses in Nursing, Physiotherapy, Cardiopneumology and Radiology. As research instrument, it was used a questionnaire with rating scales on ‘sexual attitudes’, ‘contraception attitudes’, ‘locus of health control’ and ‘self-esteem’. The data obtained was analyzed using descriptive and inferential statistics. Results: The majority of students (90.7% have already had sexual intercourse. Sexual attitudes were influenced by gender (p=0.0035, but not by the start of sexual activity or by the course’s year (p>0.05. Contraceptive attitudes were related to the year that students attended (p=0.031 and to gender (p=0.029. The external locus of control, on average, was higher among girls (29.2 than boys (30.1. The self-esteem increased with the student’s age (p=0.003. Conclusion: Investment in the area of sexual education is needed in the undergraduate programs, since the young people live their days in the school setting, spending little time with their families. The university should assume a special position in the development of the concept of sexuality based on the holistic perspective of the human being, promoting sexual education as essential in the construction of human identity and fundamental for health promotion doi: http://dx.doi.org/10.5020/18061230.2013.p505

  19. Opportunities for Improved Chagas Disease Vector Control Based on Knowledge, Attitudes and Practices of Communities in the Yucatan Peninsula, Mexico

    Science.gov (United States)

    Rosecrans, Kathryn; Cruz-Martin, Gabriela; King, Ashley; Dumonteil, Eric

    2014-01-01

    Background Chagas disease is a vector-borne parasitic disease of major public health importance. Current prevention efforts are based on triatomine vector control to reduce transmission to humans. Success of vector control interventions depends on their acceptability and value to affected communities. We aimed to identify opportunities for and barriers to improved vector control strategies in the Yucatan peninsula, Mexico. Methodology/principal findings We employed a sequence of qualitative and quantitative research methods to investigate knowledge, attitudes and practices surrounding Chagas disease, triatomines and vector control in three rural communities. Our combined data show that community members are well aware of triatomines and are knowledgeable about their habits. However, most have a limited understanding of the transmission dynamics and clinical manifestations of Chagas disease. While triatomine control is not a priority for community members, they frequently use domestic insecticide products including insecticide spray, mosquito coils and plug-in repellents. Families spend about $32 US per year on these products. Alternative methods such as yard cleaning and window screens are perceived as desirable and potentially more effective. Screens are nonetheless described as unaffordable, in spite of a cost comparable to the average annual spending on insecticide products. Conclusion/Significance Further education campaigns and possibly financing schemes may lead families to redirect their current vector control spending from insecticide products to window screens. Also, synergism with mosquito control efforts should be further explored to motivate community involvement and ensure sustainability of Chagas disease vector control. PMID:24676038

  20. Effects of a mixed media education intervention program on increasing knowledge, attitude, and compliance with standard precautions among nursing students: A randomized controlled trial.

    Science.gov (United States)

    Xiong, Peng; Zhang, Jun; Wang, Xiaohui; Wu, Tat Leong; Hall, Brian J

    2017-04-01

    Standard precautions (SPs) are considered fundamental protective measures to manage health care-associated infections and to reduce occupational health hazards. This study intended to assess the effectiveness of a mixed media education intervention to enhance nursing students' knowledge, attitude, and compliance with SPs. A randomized controlled trial with 84 nursing students was conducted in a teaching hospital in Hubei, China. The intervention group (n = 42) attended 3 biweekly mixed media education sessions, consisting of lectures, videos, role-play, and feedback with 15-20 minutes of individual online supervision and feedback sessions following each class. The control group learned the same material through self-directed readings. Pre- and posttest assessments of knowledge, attitudes, and compliance were assessed with the Knowledge with Standard Precautions Questionnaire, Attitude with Standard Precautions Scale, and the Compliance with Standard Precautions Scale, respectively. The Standard Bacterial Colony Index was used to assess handwashing effectiveness. At 6-week follow-up, performance on the Knowledge with Standard Precautions Questionnaire, Attitude with Standard Precautions Scale, and Compliance with Standard Precautions Scale were significantly improved in the intervention group compared with the control group (P < .01). The hand hygiene standard in the intervention group (38 passed) outperformed the control group (23 passed) (P < .01). A mixed media education intervention is effective in improving knowledge, attitude, and compliance with SPs. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  1. Pig farmers' perceptions, attitudes, influences and management of information in the decision-making process for disease control.

    Science.gov (United States)

    Alarcon, Pablo; Wieland, Barbara; Mateus, Ana L P; Dewberry, Chris

    2014-10-01

    The objectives of this study were (1) to explore the factors involved in the decision-making process used by pig farmers for disease control and (2) to investigate pig farmers' attitudes and perceptions about different information sources relating to disease control. In 2011 a qualitative study involving 20 face-to-face interviews with English pig farmers was conducted. The questionnaire was composed of three parts. The first part required farmers to identify two diseases they had experienced and which were difficult to recognize and/or control. They were asked to report how the disease problem was recognized, how the need for control was decided, and what affected the choice of control approach. For the latter, a structure related to the Theory of Planned Behaviour was used. Their verbal responses were classified as associated with: (1) attitude and beliefs, (2) subjective norms, or (3) perceived behavioural control (PBC). In the second part, five key sources of information for disease control (Defra, BPEX, research from academia, internet and veterinarians) and the factors related to barriers to knowledge were investigated. Interviews were recorded and transcribed. A qualitative analysis of the text of the interview transcripts was carried out using templates. Drivers for disease control were 'pig mortality', 'feeling of entering in an economically critical situation', 'animal welfare' and 'feeling of despair'. Veterinarians were perceived by several participating farmers as the most trusted information source on disease control. However, in particular non-sustainable situations, other producers, and especially experiences from abroad, seemed to considerably influence the farmers' decision-making. 'Lack of knowledge', 'farm structure and management barriers' and 'economic constrains' were identified in relation to PBC. Several negative themes, such as 'lack of communication', 'not knowing where to look', and 'information bias' were associated with research from

  2. On the generalization of attitude accessibility after repeated attitude expression.

    Science.gov (United States)

    Descheemaeker, Mathilde; Spruyt, Adriaan; Fazio, Russell H; Hermans, Dirk

    2017-02-01

    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.

  3. Attitudes, social norms and perceived behavioral control factors influencing participation in a cooking skills program in rural Central Appalachia.

    Science.gov (United States)

    Hardin-Fanning, Frances; Ricks, JaNelle M

    2016-06-16

    A focus group session, using the Theory of Planned Behavior to guide questions and discussion, was conducted at midpoint of a 12-month cooking skills program in a rural Appalachian food desert. The purpose of this qualitative study was to determine the attitudes, subjective norms and perceived behavioral control beliefs that influenced participation in these classes. Participants viewed the classes as opportunities for social interaction and to have new experiences. Subjective norms were influenced by family members and traditional cooking. Perceived behavioral control was influenced by the opportunity to try new foods without concern of food waste, acquisition of the knowledge to introduce healthy foods into family meals and enhanced food preparation skills. During the evaluation, a strong sense of participant appreciation of researcher presence was discovered. This unexpected positive component of the program will be promoted using motivational interviewing techniques to enhance adherence to healthy eating behaviors during and after cooking skills programs. © The Author(s) 2016.

  4. Application of fuzzy logic-neural network based reinforcement learning to proximity and docking operations: Attitude control results

    Science.gov (United States)

    Jani, Yashvant

    1992-01-01

    As part of the RICIS activity, the reinforcement learning techniques developed at Ames Research Center are being applied to proximity and docking operations using the Shuttle and Solar Max satellite simulation. This activity is carried out in the software technology laboratory utilizing the Orbital Operations Simulator (OOS). This report is deliverable D2 Altitude Control Results and provides the status of the project after four months of activities and outlines the future plans. In section 2 we describe the Fuzzy-Learner system for the attitude control functions. In section 3, we provide the description of test cases and results in a chronological order. In section 4, we have summarized our results and conclusions. Our future plans and recommendations are provided in section 5.

  5. The Effects of Peer-Controlled or Moderated Online Collaboration on Group Problem Solving and Related Attitudes

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    Ke Zhang

    2003-10-01

    Full Text Available Abstract. This study investigated the relative benefits of peer-controlled and moderated online collaboration during group problem solving. Thirty-five self-selected groups of four or five students were randomly assigned to the two conditions, which used the same online collaborative tool to solve twelve problem scenarios in an undergraduate statistics course. A score for the correctness of the solutions and a reasoning score were analyzed. A survey was administered to reveal differences in students' related attitudes. Three conclusions were reached: 1. Groups assigned to moderated forums displayed significantly higher reasoning scores than those in the peer-controlled condition, but the moderation did not affect correctness of solutions. 2. Students in the moderated forums reported being more likely to choose to use an optional online forum for future collaborations. 3. Students who reported having no difficulty during collaboration reported being more likely to choose to use an optional online forum in the future.

  6. Knowledge, awareness, and attitude regarding infection prevention and control among medical students: a call for educational intervention

    Directory of Open Access Journals (Sweden)

    Ibrahim AA

    2016-08-01

    Full Text Available Awab Ali Ibrahim,1 Sittana Shamseldin Elshafie,2 1Department of Physiology and Biophysics, Weill Cornell Medical College in Qatar, 2Aspetar, Laboratory Department, Qatar Orthopedic and Sports Medicine Hospital, Doha, Qatar Background: Medical students can be exposed to serious health care-associated infections, if they are not following infection prevention and control (IPC measures. There is limited information regarding the knowledge, awareness, and practices of medical students regarding IPC and the educational approaches used to teach them these practices. Aim: To evaluate the knowledge, awareness, and attitude of medical students toward IPC guidelines, and the learning approaches to help improve their knowledge. Methods: A cross-sectional, interview-based survey included 73 medical students from Weill Cornell Medical College, Qatar. Students completed a questionnaire concerning awareness, knowledge, and attitude regarding IPC practices. Students’ knowledge was assessed by their correct answers to the survey questions. Findings: A total of 48.44% of the respondents were aware of standard isolation precautions, 61.90% were satisfied with their training in IPC, 66.13% were exposed to hand hygiene training, while 85.48% had sufficient knowledge about hand hygiene and practiced it on a routine basis, but only 33.87% knew the duration of the hand hygiene procedure. Conclusion: Knowledge, attitude, and awareness of IPC measures among Weill Cornell Medical Students in Qatar were found to be inadequate. Multifaceted training programs may have to target newly graduated medical practitioners or the training has to be included in the graduate medical curriculum to enable them to adopt and adhere to IPC guidelines. Keywords: infection prevention, education, medical students

  7. Early traumatic life events, parental attitudes, family history, and birth risk factors in patients with depressive disorder and healthy controls.

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    Bandelow, Borwin; Gutermann, Julia; Peter, Helmut; Wedekind, Dirk

    2013-02-01

    Only few studies have compared the frequency of traumatic life events during childhood in inpatients with depression with a healthy control group. Consecutively admitted inpatients with depression (n = 79), most of whom belonged to the melancholic subtype (n = 73; 92.4%), and healthy controls (n = 110) were investigated using a comprehensive retrospective interview with 203 questions regarding childhood traumatic life events, parental attitudes, family history of psychiatric disorders and birth risk factors. Depressed patients had significantly more severe traumatic events (mean score 1.33; SD 1.4) than control subjects (0.85; SD 1.2) on a 0-10 point "severe trauma scale". 70.9% (n = 56) of the depressed patients, but only 48.2% (n = 53) of the controls reported at least one severe traumatic event. When looking at single events, only few differences were found between patients and controls. Compared to controls, patients described significantly higher rates of psychiatric disorders in their families, in particular depression. Parental rearing styles were rated as more unfavorable in the patient group. In a logistic regression model, of all possible etiological factors examined, only a family history of psychiatric disorders showed a significant influence (OR = 3.6). Melancholic depression seems to be less associated with traumatic events than other psychiatric disorders.

  8. The influence of patient's consciousness regarding high blood pressure and patient's attitude in face of disease controlling medicine intake.

    Science.gov (United States)

    Strelec, Maria Aparecida A Moura; Pierin, Angela M G; Mion, Décio

    2003-10-01

    To assess the relation between blood pressure control and the following: the Morisky-Green test, the patient's consciousness regarding high blood pressure, the patient's attitude in face of medicine intake, the patient's attendance at medical consultations, and the subjective physician's judgment. We studied 130 hypertensive patients with the following characteristics: 73% females, 60 +/- 11 years, 58% married, 70% white, 45% retired, 45% with incomplete elementary schooling, 64% had a familial income of 1 to 3 minimum wages, body mass index of 30 +/- 7 kg/m , consciousness regarding the disease for a mean period of 11 +/- 9.5 years, and mean treatment duration of 8 +/- 7 years. Only 35% of the hypertensive individuals had blood pressure under control and a longer duration of treatment (10 +/- 7 vs 7 +/- 6.5 years; Pface of medicine intake, the controlled patients achieved significantly higher scores than did the noncontrolled patients (8 +/- 1.9 vs 7 +/- 2, Pconsciousness regarding their disease and its treatment, and most (70%) patients attended 3 or 4 medical consultations, which did not influence blood pressure control. The physicians attributed significantly higher scores regarding adherence to treatment to controlled patients (6 +/- 0.8 vs 5 +/- 1.2; PConsciousness regarding the disease, the Morisky-Green test, and attendance to medical consultations did not influence blood pressure control.

  9. Fault detection and isolation of the attitude control subsystem of spacecraft formation flying using extended Kalman filters

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    Ghasemi, S.; Khorasani, K.

    2015-10-01

    In this paper, the problem of fault detection and isolation (FDI) of the attitude control subsystem (ACS) of spacecraft formation flying systems is considered. For developing the FDI schemes, an extended Kalman filter (EKF) is utilised which belongs to a class of nonlinear state estimation methods. Three architectures, namely centralised, decentralised, and semi-decentralised, are considered and the corresponding FDI strategies are designed and constructed. Appropriate residual generation techniques and threshold selection criteria are proposed for these architectures. The capabilities of the proposed architectures for accomplishing the FDI tasks are studied through extensive numerical simulations for a team of four satellites in formation flight. Using a confusion matrix evaluation criterion, it is shown that the centralised architecture can achieve the most reliable results relative to the semi-decentralised and decentralised architectures at the expense of availability of a centralised processing module that requires the entire team information set. On the other hand, the semi-decentralised performance is close to the centralised scheme without relying on the availability of the entire team information set. Furthermore, the results confirm that the FDI results in formations with angular velocity measurement sensors achieve higher level of accuracy, true faulty, and precision, along with lower level of false healthy misclassification as compared to the formations that utilise attitude measurement sensors.

  10. Knowledge, attitudes and practices among parents and teachers about soil-transmitted helminthiasis control programs for school children in Guimaras, Philippines.

    Science.gov (United States)

    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.

  11. Changes in eating attitudes, body esteem and weight control behaviours during adolescence in a South African cohort.

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    Tabither M Gitau

    Full Text Available Failure to consume an adequate diet or over consumption during adolescence can disrupt normal growth and development, resulting in undesirable weight change. This leads to an increase in unhealthy weight control practices related to eating and exercise among both adolescent girls and boys to meet the societal 'ideal' body shape. This study therefore aims to examine the longitudinal changes in eating attitudes, body-esteem and weight control behaviours among adolescents between 13 and 17 years; and, to describe perceptions around body shape at age 17 years. A total of 1435 urban South African black and mixed ancestry boys and girls, who had data at both age 13 and 17 years from the Birth to Twenty cohort were included. Data were collected through self-administered questionnaires on eating attitudes (EAT-26, body esteem and weight control behaviours for either weight loss or muscle gain attempts. Height and weight were measured at both time points and BMI was calculated. Black females had a higher BMI (p<0.001 and an increased risk of developing eating disorders as well as significant increase in the prevalence of weight loss practices between the ages 13 and 17 years. At age 17 years both Mixed ancestry adolescents had lower body-esteem compared to black adolescents. The prevalence of possible eating disorders was 11% and 13.1% in early and late adolescents respectively. Males and females shared similar opinions on normal silhouettes being the 'best', 'getting respect' and being the 'happiest', while the obese silhouette was associated with the 'worst' and the 'unhappiest', and the underweight silhouette with the "weakest". Black females had a higher BMI and an increased risk of developing eating disorders. Adolescent females engaged more in weight loss practices whereas, males in muscle gain practices indicating that Western norms of thinness as the ideal are becoming more common in South Africa.

  12. Knowledge, Attitude and Practice of Nurses Regarding Nosocomial Infections Control in Teaching Hospitals of Kermanshah University of Medical Sciences, Iran (2015

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    Farid Najafi

    2017-10-01

    Full Text Available Background & Aims of the Study: About a third of mortality in hospitals devoted to nosocomial infections. Nosocomial infection is an infection after the exposure of health- treatment services in unit's treatment. Lack of knowledge or ignorance of personnel to transmission methods and prevention of nosocomial infections are caused transmission of infectious diseases to staffs and patients. The aim of this research was the investigation of knowledge, attitude and practice of nurses from control methods of nosocomial infections. Materials & Methods: This research is a cross- sectional study. 200 person of the nurses of working in teaching hospitals of Kermanshah university of Medical sciences were investigated, using questionnaire. The validity of questionnaire as context evaluated by expert individuals and their reliability evaluated by Cronbach's alpha 75%. Data analysis was carried out, using SPSS 16, chi–square test and exact fisher test. Results: Investigation results showed that 69.5% nurses had good knowledge, 61.5% mean attitude and 80% good practice have into nosocomial infections control. Access to disinfectant was caused practice better than knowledge and attitude. There was a significant difference between knowledge, attitude and practice. Also, a significant difference was observed between education and attitude. Conclusion: Most of nurses have good knowledge and practice into nosocomial infections control. As regards to the important role of nurses in prevention of nosocomial infections, education of them is need for increase of prevention behaviors.

  13. Evaluation of two intervention models on contraceptive attitudes and behaviors among nulliparous women in Shanghai, China: a clustered randomized controlled trial.

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    He, Yuan; Zhang, Ning; Wang, Jue; He, Na; Du, Yan; Ding, Jing-Xin; Zhang, Ying; Li, Xiao-Tian; Huang, Jian; Hua, Ke-Qin

    2017-06-15

    With increasing acceptance of premarital sex among young Chinese women, the rates of unintended pregnancies and induced abortions are becoming alarmingly high, suggesting the needs of educating women with adequate contraceptive knowledge and providing them with accessible contraceptive services. Previous studies have shown that knowledge and attitudes towards contraception could be modified through intervention strategies. This study aimed to evaluate the effects of two community intervention models on modifying contraceptive attitudes and behaviors among nulliparous women. In this clustered randomized controlled trial, nulliparous women aged 18-40 years from 18 communities were enrolled and randomized to either the traditional community intervention model (TC model) or the more comprehensive new community-based intervention model (NC model) with a ratio of 1:2. Contraceptive attitudes and behaviors were assessed before and after the interventions. A total of 901 nulliparous women were followed. The most common contraceptive method in both groups was condom (approximately 80%) before or after interventions. The rates of using effective contraceptive methods were very low (women held negative attitudes and behaviors towards effective contraceptive methods. The NC model, integrating existing health resources, had more positive influence than the TC model on the favorable contraceptive attitudes and behaviors towards the use of any contraceptive methods, but had limited impact on the use of effective contraceptive methods. Our study suggested the feasibility of applying the NC model in Shanghai. Interventions on contraceptive attitudes and behaviors should base on the existing health service system, synthesize resources and selectively apply to populations with distinct characteristics.

  14. Metabolic Control, Nutrition Knowledge, Attitude and Practice in Non-Insulin-dependent Diabetic Patients from Kohgiluyeh and Boyer-Ahmad Province, South-West of Iran

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    Janmohamad Malekzadeh

    2016-07-01

    Full Text Available Background and Objectives: Diabetes mellitus is among the most common causes of mortality in the world and an important risk factor for chronic kidney disease, foot amputation, ischemic heart disease and blindness among older adults. Diabetic patients mostly develop hyperlipidemia, which can result in cardiovascular diseases. Patient’s knowledge, attitude and practices toward diet are the core center for diabetes control and affect their metabolic control and complications. In the present study, we measured nutritional knowledge, attitude and practices and their relations to serum lipids, HbA1C, and fasting blood glucose in diabetic patients of Boirahmad County, southwest of Iran, where many people encounter increasing prevalence of diabetes. Materials and Methods: 198 IDDM patients from the rural and urban areas of Boirahmad County were invited to the health centers to be checked for their fasting blood glucose, serum total cholesterol, serum HDL cholesterol, serum triglyceride and also serum glycosylated hemoglobin. Their knowledge, attitude, and practices toward the diabetic diet were assessed using a validated questionnaire. The obtained scores were classified into three categories (Poor, average, and Good to show their knowledge, attitude and practice levels, and the serum parameters were compared between the levels to show the relevancies. Results: Our data showed that the patients’ knowledge and attitude on diabetic nutrition are mostly at the average level (79.3% and 47.1%, respectively but their practice scores are mostly at the poor level (43.8%, and just a minor proportion of the patients are at the appropriate levels (15.3, 33, and 23.1% of knowledge, attitude and practices, respectively. In addition, we found a significant reverse relationship between the patients’ nutritional knowledge and  serum HbA1C (p=0.003, and also between their attitude and serum triglyceride (p<0.05. Conclusions: Our data suggest that the knowledge

  15. In-orbit performance of the ITOS improved attitude control system with Hall generator brushless motor and earth-splitting technique

    Science.gov (United States)

    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.

  16. Control, Norms, and Attitudes: Differences Between Students Who Do and Do Not Intervene as Bystanders to Sexual Assault.

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    Hoxmeier, Jill C; Flay, Brian R; Acock, Alan C

    2016-01-14

    Sexual assault is a major concern on the U.S. college campus. Engaging students as pro-social bystanders has become more common as a potentially effective mechanism for reducing the incidence of sexual assault and mitigating the harm of assaults that have already occurred. Understanding the influences of pro-social bystander behavior is imperative to developing effective programs, and the use of an evidence-based theoretical framework can help identify the differences between students who intervene and those who do not when presented with the opportunity. A sample of 815 undergraduate university students completed the Sexual Assault Bystander Behavior Questionnaire, a survey based on the theory of planned behavior (TPB) that investigates students' perceived behavioral control to intervene, subjective norms that support intervening, attitudes toward intervening, and intent to intervene in the future. Two-tailed t tests revealed interveners reported significantly greater perceived behavioral control than non-interveners for eight of the 12 intervention behaviors, more supportive subjective norms than non-interveners for seven of the 12 intervention behaviors, more positive attitudes than non-interveners for only one of the 12 intervention behaviors, and greater intent to intervene in the future for six of the 12 intervention behaviors. Differences in the four TPB variables were not consistent for the 12 intervention behaviors. The use of a theoretical framework found to be effective in explaining-and changing-other health-related behaviors, and the inquiry into students' opportunities to intervene to compare against their reported intervention behaviors, is new to this body of literature and contributes to the understanding of the influences of pro-social bystander behavior. © The Author(s) 2016.

  17. Effect of an oral healthcare protocol in nursing homes on care staffs' knowledge and attitude towards oral health care: a cluster-randomised controlled trial.

    Science.gov (United States)

    Janssens, Barbara; De Visschere, Luc; van der Putten, Gert-Jan; de Lugt-Lustig, Kersti; Schols, Jos M G A; Vanobbergen, Jacques

    2016-06-01

    To explore the impact of a supervised implementation of an oral healthcare protocol, in addition to education, on nurses' and nurses' aides' oral health-related knowledge and attitude. A random sample of 12 nursing homes, accommodating a total of 120-150 residents, was obtained using stratified cluster sampling with replacement. The intervention included the implementation of an oral healthcare protocol and three different educational stages. One of the investigators supervised the implementation process, supported by a dental hygienist. A 34-item questionnaire was developed and validated to evaluate the knowledge and attitude of nurses and nurses' aides at baseline and 6 months after the start of the intervention. Linear mixed-model analyses were performed to explore differences in knowledge and attitude at 6 months after implementation. At baseline, no significant differences were observed between the intervention and the control group for both knowledge (p = 0.42) and attitude (p = 0.37). Six months after the start of the intervention, significant differences were found between the intervention and the control group for the variable knowledge in favour of the intervention group (p attitude (p = 0.78). Out of the mixed model with attitude as the dependent variable, it can be concluded that age (p = 0.031), educational level (p = 0.009) and ward type (p = 0.014) have a significant effect. The mixed model with knowledge as the dependent variable resulted in a significant effect of the intervention (p = 0.001) and the educational level (p = 0.009). The supervised implementation of an oral healthcare protocol significantly increased the knowledge of nurses and nurses' aides. In contrast, no significant improvements could be demonstrated in attitude. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  18. Parental attitude, depression, anxiety in mothers, family functioning and breath-holding spells: A case control study.

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    Eliacik, Kayi; Bolat, Nurullah; Kanik, Ali; Sargin, Enis; Selkie, Ellen; Korkmaz, Nurhan; Baydan, Figen; Akar, Ebru; Sarioglu, Berrak

    2016-05-01

    This study aimed to identify differences in the antenatal stressful life events, parenting style, family functioning, depression and anxiety of mothers who have children with breath-holding spells (BHS) compared with controls. This case control study divided 66 children into a group of children with BHS and a control group, with the children's ages ranging between 6 months and 5 years of age. This study explored underlying anxiety and depression in mothers as well as functioning of their families. Socio-demographical data and stressful life events that the mother experienced during pregnancy were analysed. In order to evaluate the effects of family structure, depression and anxiety in mothers on BHS in children, the Family Assessment Device, and both the Parental Attitude Research Instrument and the Beck Depression Inventory as well as the State-Trait Anxiety Inventory were used to assess both groups. Exposure to stressful life events during pregnancy (P anxiety (P anxiety, depression, prenatal stressful events and poor family functioning in mothers who have children with BHS is significantly higher than controls. An evaluation of these problems may be beneficial in the management of BHS. © 2016 The Authors. Journal of Paediatrics and Child Health © 2016 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  19. Effect of infection control strategy on knowledge, attitude and practice towards hepatitis B transmission and prevention in vulnerable populations.

    Science.gov (United States)

    Al-Tawil, M M; El-Gohary, E E; El-Sayed, M H

    2013-01-01

    Health care workers (HCWs) and hematological patients needing blood/ blood product transfusion are particularly vulnerable to blood born infections (BBI) including viral hepatitis. To evaluate knowledge, attitude and practice (KAP) of these target groups regarding viral hepatitis B (HBV) transmission and its change with implementing infection control policy and procedures. An anonymous questionnaire with closed questions was used to evaluate KAP including vaccination status in 2 target groups, in Children Hospital, Ain Shams University, Cairo, Egypt: 184 nurses and 210 children and adolescents with blood diseases. One year after instituting infection control as a part of hospital procedures, the same questionnaire was reused to evaluate KAP towards HBV. Baseline knowledge regarding HBV transmission, sequelae and preventive measures, was poor in both groups. Among nurses, only 62% wore gloves on withdrawing or giving blood to patients, 43.5% routinely washed hands between patients and 37.5% reported exposure after sharp injury. Only 38% of patients and 40% of nurses received HBV vaccination. Targeted infection control policy and procedures significantly improved KAP regarding HBV in both groups. Vaccination coverage significantly increased and reached 88.7% for nurses and 72% for patients. Hospital based infection control units with established policy and procedures against BBI significantly improved KAP towards HBV including a significant increase in vaccination intake.

  20. Effects of news media messages about mass shootings on attitudes toward persons with serious mental illness and public support for gun control policies.

    Science.gov (United States)

    McGinty, Emma E; Webster, Daniel W; Barry, Colleen L

    2013-05-01

    In recent years, mass shootings by persons with serious mental illness have received extensive news media coverage. The authors test the effects of news stories about mass shootings on public attitudes toward persons with serious mental illness and support for gun control policies. They also examine whether news coverage of proposals to prevent persons with serious mental illness from having guns exacerbates the public's negative attitudes toward this group. The authors conducted a survey-embedded randomized experiment using a national sample (N=1,797) from an online panel. Respondents were randomly assigned to groups instructed to read one of three news stories or to a no-exposure control group. The news stories described, respectively, a mass shooting by a person with serious mental illness, the same mass shooting and a proposal for gun restrictions for persons with serious mental illness, and the same mass shooting and a proposal to ban large-capacity magazines. Outcome measures included attitudes toward working with or living near a person with serious mental illness, perceived dangerousness of persons with serious mental illness, and support for gun restrictions for persons with serious mental illness and for a ban on large-capacity magazines. Compared with the control group, the story about a mass shooting heightened respondents' negative attitudes toward persons with serious mental illness and raised support for gun restrictions for this group and for a ban on large-capacity magazines. Including information about the gun restriction policy in a story about a mass shooting did not heighten negative attitudes toward persons with serious mental illness or raise support for the restrictions. The aftermath of mass shootings is often viewed as a window of opportunity to garner support for gun control policies, but it also exacerbates negative attitudes toward persons with serious mental illness.

  1. Attitudes of veterinarians, animal control directors, and county prosecutors in Michigan regarding enforcement of state animal cruelty legislation.

    Science.gov (United States)

    Stolt, L B; Johnson-Ifearulundu, Y J; Kaneene, J B

    1997-12-15

    To determine attitudes of veterinarians, animal control directors, and country prosecutors in Michigan toward enforcement of state animal cruelty legislation and to identify factors associated with whether veterinarians would report suspected cases of animal cruelty. Survey. Questionnaires were sent to 1,146 Michigan Veterinary Medical Association member veterinarians, 139 animal control directors, and 83 county prosecutors in Michigan. 740 (65%) veterinarians, 70 (50%) animal control directors, and 43 (52%) prosecutors responded. Six hundred forty six of 735 (88%) veterinarians reported having treated an animal that they believed had been a victim of animal cruelty, but only 192 of 719 (27%) had ever reported a case of animal cruelty, and only 217 of 734 (30%) had ever testified in an animal cruelty case. Logistic regression analysis of responses revealed that the only factor associated with whether veterinarians would report cases of suspected animal cruelty was the potential reactions of the involved clients to the accusation of animal cruelty. Veterinarians who rated reaction of the involved client as important, very important, or essential to their decision whether to report a case of animal cruelty were less likely to report such cases than were veterinarians who rated potential client reaction as somewhat important or unimportant. Concern about potential client reaction was the most important factor in whether veterinarians would report cases of suspected animal cruelty.

  2. Predictors of Attitudes toward Childlessness.

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    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…

  3. Do the Psychological Constructs of Attitude, Perceived Norm, and Perceived Behavioral Control Explain a Woman's Intention to Use Mobile Business Applications, across Cultures?

    Science.gov (United States)

    Bradley, Deirdre Elyse

    2015-01-01

    A reasoned action approach (RAA) was used to assess the importance of psychological factors (attitude, perceived norm, and perceived behavioral control) in forming a woman's intention to use mobile technology, specifically mobile business applications. This study also examined whether the significance of these factors varied across cultures. An…

  4. Using E-Portfolios in a Field Experience Placement: Examining Student-Teachers' Attitudes towards Learning in Relationship to Personal Value, Control and Responsibility

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    Shroff, Ronnie H.; Trent, John; Ng, Eugenia M. W.

    2013-01-01

    This study extends the ownership of learning model by using e-portfolios in a field experience placement to examine student-teachers' attitudes towards learning in relationship to personal value, feeling in control and taking responsibility. A research model is presented based on research into ownership of learning. The student e-portfolio…

  5. A Structural Equation Model To Investigate the Delivery of Child Sex Abuse Services as a Consequence of Attitude, Locus of Control, and the Work Setting.

    Science.gov (United States)

    Ferrara, F. Felicia

    A structural equation model was proposed to explore influencing factors that may contribute to school psychologists' role inhibition versus progressive pursuits towards the delivery of child sex abuse services. Three work-related variables (attitude, locus of control, work-setting demands) were examined to assess their impact on the initiatives…

  6. A Between- and Within-Person Analysis of Parenting And Time Spent in Criminogenic Settings during Adolescence: The Role of Self-Control And Delinquent Attitudes

    Science.gov (United States)

    Janssen, Heleen J.; Bruinsma, Gerben J. N.; Dekovic, Maja; Eichelsheim, Veroni I.

    2018-01-01

    Although spending time in criminogenic settings is increasingly recognized as an explanation for adolescent delinquency, little is known about its determinants. The current study aims to examine the extent to which (change in) self-control and (change in) delinquent attitudes relate to (change in) time spent in criminogenic settings, and the…

  7. Educational Differences in Associations of Noticing Anti-Tobacco Information with Smoking-Related Attitudes and Quit Intentions: Findings from the International Tobacco Control Europe Surveys

    Science.gov (United States)

    Springvloet, L.; Willemsen, M. C.; Mons, U.; van den Putte, B.; Kunst, A. E.; Guignard, R.; Hummel, K.; Allwright, S.; Siahpush, M.; de Vries, H.; Nagelhout, G. E.

    2015-01-01

    This study examined educational differences in associations of noticing anti-tobacco information with smoking-related attitudes and quit intentions among adult smokers. Longitudinal data (N = 7571) from two waves of six countries of the International Tobacco Control (ITC) Europe Surveys were included. Generalized estimating equation analyses and…

  8. Severe obesity and diabetes self-care attitudes, behaviours and burden : Implications for weight management from a matched case-controlled study. Results from Diabetes MILES-Australia

    NARCIS (Netherlands)

    Dixon, J.B.; Browne, J.L.; Mosely, K.G.; Jones, K.M.; Pouwer, F.; Speight, J.

    2014-01-01

    Aims To investigate whether diabetes self-care attitudes, behaviours and perceived burden, particularly related to weight management, diet and physical activity, differ between adults with Type 2 diabetes who are severely obese and matched non-severely obese control subjects. Methods The 1795

  9. Onboard Supervisor for the Ørsted Satellite Attitude Control System

    DEFF Research Database (Denmark)

    Bøgh, S.A.; Izadi-Zamanabadi, Roozbeh; Blanke, M.

    1995-01-01

    The increasing operational requirements for onboard autonomy in satellite control systems necessitates structural methods that support the design of a complete and reliable supervisory system.......The increasing operational requirements for onboard autonomy in satellite control systems necessitates structural methods that support the design of a complete and reliable supervisory system....

  10. Teachers' Attitude toward Decision Making as a Subcategory of Learner's Control Strategy

    Science.gov (United States)

    Kutlu, M. Oguz

    2012-01-01

    The aim of this study was to determine the usage levels of learner's control strategy among teachers according to their field and length of service in using option of decision making covered by learner's control strategy. The participants of this research were 219 teachers teaching in Adana (Turkey) State primary schools in 2010 to 2011 education…

  11. Wave-Based Attitude Control of Spacecraft with Fuel Sloshing Dynamics

    Directory of Open Access Journals (Sweden)

    Thompson Joseph William

    2016-06-01

    Full Text Available Wave-Based Control has been previously applied successfully to simple under-actuated flexible mechanical systems. Spacecraft and rockets with structural flexibility and sloshing are examples of such systems but have added difficulties due to non-uniform structure, external disturbing forces and non-ideal actuators and sensors. The aim of this paper is to extend the application of WBC to spacecraft systems, to compare the performance of WBC to other popular controllers and to carry out experimental validation of the designed control laws. A mathematical model is developed for an upper stage accelerating rocket moving in a single plane. Fuel sloshing is represented by an equivalent mechanical pendulum model. A wave-based controller is designed for the upper stage AVUM of the European launcher Vega. In numerical simulations the controller successfully suppresses the sloshing motion. A major advantage of the strategy is that no measurement of the pendulum states (sloshing motion is required.

  12. The H(sub infinity) optimal controller design and reduction for the inertial hold mode of the attitude control system of the XTE spacecraft

    Science.gov (United States)

    Xu, Zhong Ling; Zhou, Gui AN

    1994-01-01

    The Inertial Hold Mode (IHM) is one mode of the attitude control system of the X-ray Timing Explorer spacecraft that is disturbed by both parametric uncertainties and external torque disturbance. The IHM model is modified into a typical H-infinity mixed-sensitivity problem through choosing suitable weighting functions W(sub 1)(s) and W(sub 3)(s). The controller is designed by the H-infinity optimization technique with the transformation of shifting the imaginary axis. It can stabilize the plant with uncertainties from the natural frequencies of the flexible body. The gain margin and phase margin of the system are 24.03 db and 55.04 deg, respectively. The step response attenuates to zero within 150 seconds. These show that the controller satisfies the specified requirements. Since the order of the controller appears high, it is reduced to fourth order one. The results show that the stability and the performance of the system with the reduced controller are retained perfectly.

  13. Attitude Control of a Single Tilt Tri-Rotor UAV System: Dynamic Modeling and Each Channel's Nonlinear Controllers Design

    Directory of Open Access Journals (Sweden)

    Juing-Shian Chiou

    2013-01-01

    Full Text Available This paper has implemented nonlinear control strategy for the single tilt tri-rotor aerial robot. Based on Newton-Euler’s laws, the linear and nonlinear mathematical models of tri-rotor UAVs are obtained. A numerical analysis using Newton-Raphson method is chosen for finding hovering equilibrium point. Back-stepping nonlinear controller design is based on constructing Lyapunov candidate function for closed-loop system. By imitating the linguistic logic of human thought, fuzzy logic controllers (FLCs are designed based on control rules and membership functions, which are much less rigid than the calculations computers generally perform. Effectiveness of the controllers design scheme is shown through nonlinear simulation model on each channel.

  14. Parasitic worms: knowledge, attitudes, and practices in Western Côte d'Ivoire with implications for integrated control.

    Directory of Open Access Journals (Sweden)

    Cinthia A Acka

    Full Text Available BACKGROUND: In the developing world where parasitic worm infections are pervasive, preventive chemotherapy is the key strategy for morbidity control. However, local knowledge, attitudes, and practices (KAP of parasitic worms are poorly understood, although such information is required for prevention and sustainable control. METHODS: We carried out KAP surveys in two rural communities of Côte d'Ivoire that were subjected to school-based and community-based research and control activities. We used qualitative and quantitative methods. The former included observations, in-depth interviews with key informants, and focus group discussions with school children and adults. Quantitative methods consisted of a structured questionnaire administered to household heads. PRINCIPAL FINDINGS: Access to clean water was lacking in both communities and only a quarter of the households had functioning latrines. There was a better understanding of soil-transmitted helminthiasis than intestinal schistosomiasis, but community-based rather than school-based interventions appeared to improve knowledge of schistosomiasis. In the villages with community-based interventions, three-quarters of household interviewees knew about intestinal schistosomiasis compared to 14% in the village where school-based interventions were implemented (P<0.001. Whereas two-thirds of respondents from the community-based intervention village indicated that the research and control project was the main source of information, only a quarter of the respondents cited the project as the main source. CONCLUSIONS/SIGNIFICANCE: Preventive chemotherapy targeting school-aged children has limitations, as older population segments are neglected, and hence lack knowledge about how to prevent and control parasitic worm infections. Improved access to clean water and sanitation is necessary, along with health education to make a durable impact against helminth infections.

  15. Racism, gun ownership and gun control: biased attitudes in US whites may influence policy decisions

    National Research Council Canada - National Science Library

    O'Brien, Kerry; Forrest, Walter; Lynott, Dermot; Daly, Michael

    2013-01-01

    .... The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites...

  16. Active disturbance rejection attitude control for a hypersonic reentry vehicle with actuator saturation

    Directory of Open Access Journals (Sweden)

    Hongjiu Yang

    2017-05-01

    Full Text Available In this article, nonlinear uncertainty has been investigated for a hypersonic reentry vehicle subject to actuator saturation via active disturbance rejection control technology. A nonlinear extended state observer is designed to estimate “total disturbances,” which is compensated with a linear controller. Both convergence of the nonlinear extended state observer and stabilization of the closed-loop system are studied in this article. Some simulation results are given to illustrate the effectiveness of the proposed method.

  17. Capability of Parallel Mechanism Used for Attitude Control of "Millimetron" Space Telescope

    Directory of Open Access Journals (Sweden)

    Yu. N. Artemenko

    2014-01-01

    Full Text Available "Millimetron" space observatory project is introduced. Essential technical requirements and capabilities are given. Two possible design approaches regarding telescope position control are discussed. Several designs of a multi-sectional manipulator for antenna position control are considered. Problem of trajectory synthesis for moving the manipulator to the command position is formulated. Forward and inversed kinematics problems are stated. Two methods for solving trajectory synthesis problem are introduced. Programmatic solution is implemented and described. Further development directions are designated.

  18. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions

    OpenAIRE

    Kerry O'Brien; Walter Forrest; Dermot Lynott; Michael Daly

    2013-01-01

    OBJECTIVE: Racism is related to policies preferences and behaviors that adversely affect blacks and appear related to a fear of blacks (e.g., increased policing, death penalty). This study examined whether racism is also related to gun ownership and opposition to gun controls in US whites. METHOD: The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US wh...

  19. Smoking Prevalence and Associated Factors as well as Attitudes and Perceptions towards Tobacco Control in Northeast China

    Directory of Open Access Journals (Sweden)

    Zhijun Li

    2015-07-01

    Full Text Available Objectives: The present study aimed to investigate the prevalence of smoking and environmental tobacco smoke (ETS, the associated factors of current smoking among adults, and their attitudes and perceptions towards tobacco control. Methods: A population-based cross-sectional survey was conducted in 2012 using a self-reported questionnaire. A representative sample of adults aged 18–79 years was collected in the Jilin Province of Northeast China by a multistage stratified random cluster sampling design. Descriptive data analysis was conducted, and 95% confidence intervals (CI of prevalence/frequency were calculated to enable comparisons between the alleged differences and similarities. Multivariable logistic regressions were used to examine the risk factors associated with current smoking. Results: 21,435 adults responded to the survey (response rate: 84.9%. The overall prevalence of ever smoking, current smoking, and former smoking or smoking cessation was 39.1% (95% CI: 38.3–39.9, 31.8% (95% CI 31.1–32.6, and 7.3% (95% CI: 6.9–7.7, respectively. The proportion of ETS exposure among adult non-smokers in Jilin Province was 61.1% (95% CI: 60.1–62.1, and 23.1% (95% CI: 22.3–24.0 of the non-smokers reported daily ETS exposure. The proportion of ETS exposure at home was 33.4% (95% CI: 32.5–34.4, but the proportion of ETS exposure at restaurants was lower (6.5% (95% CI: 6.0–7.1. More than 90% of the participants had positive attitudes and perceptions towards tobacco control, but 23.2% (95% CI: 22.5–24.0 of them did not agree with the perception of “smoking is fully quit in public places”, and almost half of the adults (49.5% (95% CI: 48.7–50.3 did not agree with the perception of “hazards of low-tar cigarettes are equal to general cigarettes”. Conclusions: Smoking and exposure to ETS are prevalent among adults from the Jilin Province of Northeast China. Our findings suggest that tobacco control should be advocated in

  20. Nonlinear fractional order proportion-integral-derivative active disturbance rejection control method design for hypersonic vehicle attitude control

    Science.gov (United States)

    Song, Jia; Wang, Lun; Cai, Guobiao; Qi, Xiaoqiang

    2015-06-01

    Near space hypersonic vehicle model is nonlinear, multivariable and couples in the reentry process, which are challenging for the controller design. In this paper, a nonlinear fractional order proportion integral derivative (NFOPIλDμ) active disturbance rejection control (ADRC) strategy based on a natural selection particle swarm (NSPSO) algorithm is proposed for the hypersonic vehicle flight control. The NFOPIλDμ ADRC method consists of a tracking-differentiator (TD), an NFOPIλDμ controller and an extended state observer (ESO). The NFOPIλDμ controller designed by combining an FOPIλDμ method and a nonlinear states error feedback control law (NLSEF) is to overcome concussion caused by the NLSEF and conversely compensate the insufficiency for relatively simple and rough signal processing caused by the FOPIλDμ method. The TD is applied to coordinate the contradiction between rapidity and overshoot. By attributing all uncertain factors to unknown disturbances, the ESO can achieve dynamic feedback compensation for these disturbances and thus reduce their effects. Simulation results show that the NFOPIλDμ ADRC method can make the hypersonic vehicle six-degree-of-freedom nonlinear model track desired nominal signals accurately and fast, has good stability, dynamic properties and strong robustness against external environmental disturbances.

  1. Design and Test of an Attitude Determination and Control System for a 6U CubeSat using AFIT’s CubeSat Testbed

    Science.gov (United States)

    2015-03-01

    Including Sensor Bias in Shape from Motion Calibration and Sensor Fusion ”. Multisensor Fusion and Integration for Intelligent Systems, 1996. IEEE/SICE...for attitude determination. Along with the ADCS hardware, the ADCS testbed also includes an Electrical Power System (EPS) and Command and Data ...eter sensor data to estimate a current quaternion. A Proportional-Integral-Derivative (PID) controller is used for control of the ADCS testbed while

  2. Knowledge and Attitude of Dental Practitioners in Tabriz Regarding Infection Control Procedures

    Directory of Open Access Journals (Sweden)

    Ali Taghavi Zenouz

    2007-12-01

    Full Text Available

    Background and aims. Blood-borne infections such as hepatitis B, hepatitis C and HIV might be transmitted from one individual to another during dental procedures. Therefore, sterilization and personal protection procedures are of utmost significance in dental offices. The importance of awareness of cross-infection and antiseptic principles lies in the fact that in most cases it is not possible to identify patients with hepatitis or AIDS. The aim of the present study was to evaluate awareness of infection control procedures among dental practitioners in Tabriz.

    Materials and methods. In this descriptive study, 150 dental practitioners working in clinics and private offices of Tabriz were randomly selected. Data was collected by means of a self-administered questionnaire, which included respondents’ personal profile and questions on infection control and sterilization methods.

    Results. There were no statistically significant differences in the level of knowledge between male and female dental practitioners regarding infection control; however, there was a decline in awareness as age increased.

    Conclusion. The results of the present study suggest that in some cases dental practitioners neglect the principles for personal protection and cross-infection control. Therefore, our society is subject to widespread infection in dental offices and clinics. This potential risk necessitates careful monitoring along with government support of treatment procedures, the inclusion of infection control costs into treatment expenses and an emphasis on continuing education about infection control procedures through seminars and congresses.

  3. Fault diagnosis in satellite attitude control systems using artificial neural networkk

    Science.gov (United States)

    Ayodele I., Olanipekun

    The nonlinear behavior exhibited by altitude control system processes and also the presence of external constraints on the operating conditions causes hitch in the dynamics of system processes. This research work proposes a fault detection/tolerant prediction in an altitude control system. This is done through the artificial neural network fault detection by deploying the neural network approach. A fault detection and isolation module is developed in the actuator system of the Altitude Control System, thereby achieving the goal of this thesis. This can be done by two basic classification stages: Neural Residual Generator (Neural Observer)- This stage is responsible for generating residual errors that can reflect the real behavior of the entire process as against its normal conditions. Adaptive Neural Classifier - This stage is responsible for managing the isolation task of the fault detected by evaluating the generated residual errors from the neural estimator which gives detailed information about faults detected e.g., fault location and time. These two stages can be implemented by executing the tasks listed below: 1. Study and develop a generic three axis stabilized altitude control model based on the reaction wheels. This is established with three separate PD controllers designed for each reaction wheel of the satellite axis using the Matlab - SIMULINK. 2. Develop a dynamic neural network residual generator based on Dynamic Multilayer Perceptron Network (DMLP) which is then applied to the reaction wheel model designed commonly called the actuator in the altitude control system of a satellite 3. Develop a neural network adaptive classifier based on the Learning Vector Quantization (LVQ) model which is used for the isolation concept. The advantages of the proposed dynamic neural network and neural adaptive classifier approach are showcased.

  4. [Factors that control personality characteristics of fertile women and their attitudes towards sexuality, pregnancy, and childbirth (author's transl)].

    Science.gov (United States)

    Maspfuhl, B

    1980-01-01

    A group of 630 probands was selected by random sampling and exposed to variance analysis to find out the extent to which extraversion and neuroticism as well as attitudes towards sexuality and gravidity depended on several conditions, such as desired pregnancy, undesired pregnancy, and no pregnancy, and on several demographic parameters, such as age, number of children, marital status, and occupational skills. The results were likely to suggest super-accidental correlations between condition and attitude towards pregnancy, age and extraversion (correlated also with condition), scare of childbirth as well as attitude towards pregnancy and sexuality, occupational skills and neuroticism, timidity as well as attitude towards sexuality and gravidity, marital status and neuroticism as well as scare of childbirth, and, finally, between number of children and scare of childbirth as well as attitude towards sexuality. Practice-related consequences are discussed.

  5. Buddha as an eye opener: a link between prosocial attitude and attentional control

    NARCIS (Netherlands)

    Colzato, L.S.; Hommel, B.; van den Wildenberg, W.P.M.; Hsieh, S.

    2010-01-01

    Increasing evidence suggests that religious practice induces systematic biases in attentional control. We used Navon's global-local task to compare attentional bias in Taiwanese Zen Buddhists and Taiwanese atheists; two groups brought up in the same country and culture and matched with respect to

  6. Consumer attitudes regarding internet health information and communication: Gender, locus of control, and stress implications

    Directory of Open Access Journals (Sweden)

    Joshua Fogel

    2009-01-01

    Full Text Available Los estudiantes universitarios utilizan internet para comunicarse y obtener información sobre salud. Se realizó un estudio descriptivo mediante una encuesta a 227 estudiantes para determinar si había diferencias entre aquellos que utilizan internet y el correo electrónico para informarse sobre salud y aquellos que no. Las variables dependientes fueron la Escala de Estrés Percibido y las subescalas de la Escala Multidimensional de Locus de Control de la Salud. Las variables independientes incluyeron preguntas sobre la utilización de internet para informarse o comunicarse con otros sobre salud. Se realizaron análisis para el total de la muestra y por género. En los tres ítems de comunicación, los que utilizaban internet/correo electrónico mostraron un nivel de estrés percibido significativamente más alto. No hubo diferencias entre los que usaban internet para buscar información sobre salud. Estos resultados se mantuvieron para hombres y se acercaron a la significación para las mujeres. Los que utilizan internet para obtener información sobre salud puntuaron significativamente más alto en la subescala de locus de control interno. Estos resultados se mantuvieron en los varones, mientras que para las mujeres fue significativa la subescala de control por otros poderes. Los hombres con estrés percibido se comunican por correo electrónico o internet sobre salud, mientras que las mujeres no. Respecto al uso de información sobre salud en internet, los hombres utilizan un locus de control interno y las mujeres un locus de control por otros poderes. Estos resultados son útiles para los profesionales que asesoren a universitarios con problemas de salud.

  7. Knowledge, Attitudes and Practices of Law Enforcement Officers on Rabies and Animal Control Issues in Kansas.

    Science.gov (United States)

    Straily, A; Trevino-Garrison, I

    2017-03-01

    Rabies is a deadly zoonoses endemic in the United States, including Kansas. Animal control programmes that emphasize vaccination of dogs and cats, removal of stray animals and enforcement of licensure programmes have historically been essential in reducing the risk of rabies exposures to humans (Beran, 1991). Kansas does not mandate the use of animal control officers [ACOs] and in areas where there is no designated animal control officer, law enforcement officers [LEOs] are required to fill that role. Little is known about LEOs' knowledge of rabies, their current practices in responding to animal-related calls or if they receive any specialized training to perform the duties of an ACO. A web-based, voluntary and anonymous survey was sent to law enforcement officers in Kansas in January 2014. The survey included questions about animal control practices and a self-assessment of rabies knowledge. The response rate was 16.2%. All respondents indicated LEOs will respond to animal-related calls, even if there was an ACO available in their department or jurisdiction. A majority of respondents indicated they had not received training on safe animal handling (62.9%, 61/97) or zoonoses prevention (85.6%, 83/97), even though a strong majority considered such training important (89.7% and 79.4%, respectively). Most respondents (>80%) were able to correctly identify animals capable of transmitting rabies but were less aware of how rabies was transmitted or the severity of rabies in humans. Our results demonstrate that Kansas LEOs perform animal control duties, many without the proper training, even though most consider such training to be important to be able to perform their duties safely. Training on safe animal handling and zoonoses prevention should be provided to all LEOs in Kansas to enable them to safely execute their duties and provide timely and accurate information to citizens regarding rabies prevention. © 2016 Blackwell Verlag GmbH.

  8. Cassini Orbit Trim Maneuvers at Saturn - Overview of Attitude Control Flight Operations

    Science.gov (United States)

    Burk, Thomas A.

    2011-01-01

    The Cassini spacecraft has been in orbit around Saturn since July 1, 2004. To remain on the planned trajectory which maximizes science data return, Cassini must perform orbit trim maneuvers using either its main engine or its reaction control system thrusters. Over 200 maneuvers have been executed on the spacecraft since arrival at Saturn. To improve performance and maintain spacecraft health, changes have been made in maneuver design command placement, in accelerometer scale factor, and in the pre-aim vector used to align the engine gimbal actuator prior to main engine burn ignition. These and other changes have improved maneuver performance execution errors significantly since 2004. A strategy has been developed to decide whether a main engine maneuver should be performed, or whether the maneuver can be executed using the reaction control system.

  9. Attitude and vibration control of a satellite containing flexible solar arrays by using reaction wheels, and piezoelectric transducers as sensors and actuators

    Science.gov (United States)

    da Fonseca, Ijar M.; Rade, Domingos A.; Goes, Luiz C. S.; de Paula Sales, Thiago

    2017-10-01

    The primary purpose of this paper is to provide insight into control-structure interaction for satellites comprising flexible appendages and internal moving components. The physical model considered herein aiming to attend such purpose is a rigid-flexible satellite consisting of a rigid platform containing two rotating flexible solar panels. The solar panels rotation is assumed to be in a sun-synchronous configuration mode. The panels contain surface-bonded piezoelectric patches that can be used either as sensors for the elastic displacements or as actuators to counteract the vibration motion. It is assumed that in the normal mode operation the satellite platform points towards the Earth while the solar arrays rotate so as to follow the Sun. The vehicle moves in a low Earth polar orbit. The technique used to obtain the mathematical model combines the Lagrangian formulation with the Finite Elements Method used to describe the dynamics of the solar panel. The gravity-gradient torque as well as the torque due to the interaction of the Earth magnetic field and the satellite internal residual magnetic moment is included as environmental perturbations. The actuators are three reaction wheels for attitude control and piezoelectric actuators to control the flexible motion of the solar arrays. Computer simulations are performed using the MATLAB® software package. The following on-orbit satellite operating configurations are object of analysis: i) Satellite pointing towards the Earth (Earth acquisition maneuver) by considering the initial conditions in the elastic displacement equal to zero, aiming the assessment of the flexible modes excitation by the referred maneuver; ii) the satellite pointing towards the Earth with the assumption of an initial condition different from zero for the flexible motion such that the attitude alterations are checked against the elastic motion disturbance; and iii) attitude acquisition accomplished by taking into account initial conditions

  10. Comprehensive Cancer Control Partners’ Use of and Attitudes About Evidence-Based Practices

    Science.gov (United States)

    Rose, John M.; Townsend, Julie S.; Fonseka, Jamila; Richardson, Lisa C.; Chovnick, Gary

    2015-01-01

    Introduction National Comprehensive Cancer Control Program (NCCCP) awardees are encouraged to work with partners (eg, nonprofit organizations) to develop and implement plans to reduce the cancer burden in their jurisdictions using evidence-based practices (EBPs). However, the extent of EBP use among awardees and their partners is not well understood. Methods From March through July 2012, we conducted a web-based survey of program partners referred by NCCCP program directors who were involved in implementation of cancer control plans. Results Approximately 53% of referred partners (n = 83) completed surveys, 91.6% of whom represented organizations. Most partners reported involvement in helping to identify (80.5%), adapt (81.7%), implement (90.4%), and evaluate (81.9%) EBPs. The factors rated most frequently as very important when selecting EBPs were “consistent with our organization’s mission” (89.2%) and “cost-effective” (81.9%). Although most respondents said that their organizations understood the importance of using EBPs (84.3%) and had adequate access to cancer registry data (74.7%), few reported having sufficient financial resources to develop new EBPs (7.9%). The most frequently mentioned benefit of using EBPs was that they are proven to work. Resource limitations and difficulty adapting EBPs for specific populations and settings were challenges. Conclusions Our findings help indicate how NCCCP partners are involved in using EBPs and can guide ongoing efforts to encourage the use of EBPs for cancer control. The challenges of using EBPs that partners identified highlight the need to improve strategies to translate cancer prevention and control research into practice in real-world settings and for diverse populations. PMID:26182148

  11. Comprehensive Cancer Control Partners' Use of and Attitudes About Evidence-Based Practices.

    Science.gov (United States)

    Steele, C Brooke; Rose, John M; Townsend, Julie S; Fonseka, Jamila; Richardson, Lisa C; Chovnick, Gary

    2015-07-16

    National Comprehensive Cancer Control Program (NCCCP) awardees are encouraged to work with partners (eg, nonprofit organizations) to develop and implement plans to reduce the cancer burden in their jurisdictions using evidence-based practices (EBPs). However, the extent of EBP use among awardees and their partners is not well understood. From March through July 2012, we conducted a web-based survey of program partners referred by NCCCP program directors who were involved in implementation of cancer control plans. Approximately 53% of referred partners (n = 83) completed surveys, 91.6% of whom represented organizations. Most partners reported involvement in helping to identify (80.5%), adapt (81.7%), implement (90.4%), and evaluate (81.9%) EBPs. The factors rated most frequently as very important when selecting EBPs were "consistent with our organization's mission" (89.2%) and "cost-effective" (81.9%). Although most respondents said that their organizations understood the importance of using EBPs (84.3%) and had adequate access to cancer registry data (74.7%), few reported having sufficient financial resources to develop new EBPs (7.9%). The most frequently mentioned benefit of using EBPs was that they are proven to work. Resource limitations and difficulty adapting EBPs for specific populations and settings were challenges. Our findings help indicate how NCCCP partners are involved in using EBPs and can guide ongoing efforts to encourage the use of EBPs for cancer control. The challenges of using EBPs that partners identified highlight the need to improve strategies to translate cancer prevention and control research into practice in real-world settings and for diverse populations.

  12. Gender Differences in the Attitude and Strategy towards Weight Control among Government Employees in Penang, Malaysia.

    Science.gov (United States)

    Aina Mardiah, B; Hazizi, As; Nasir, Mt Mohd; Zaitun, Y; Jan, Jm Hamid

    2012-01-01

    This was a cross-sectional study on the gender differences in weight-control behavior. The strategies used, weight status, weight satisfaction, and proportion of individuals attempting to lose weight among 233 government employees (104 men and 129 women) working in the Federal Government Building in Penang, Malaysia, were assessed. Anthropometric indicators such as body mass index, waist-to-hip ratio, and body fat percentage were measured to determine the subjects' body weight status. A questionnaire covering the following items was used to assess weight-control behavior: social support, self-monitoring, self-efficacy, outcome expectations, planning, preparation/buying, portion control, social interactions, and cognitive behavioral strategies. About 50% of the subjects were classified as overweight. Based on percent body fat percentage, 70% of them were classified as having unhealthy levels of body fat. Women were found to be more dissatisfied with their current weight, and were more likely to attempt weight reduction compared to men. Women reported higher levels of social support for dieting and had better expectations for diet and exercise (P 0.05) were observed, women reported more frequent self-monitoring of diet, whereas men reported more frequent self-monitoring of exercise. Health care professionals and researchers should be aware of the different strategies used by men and women in order to plan and/or implement community-wide weight management programmes.

  13. Patients' perceptions and attitudes on recurrent prostate cancer and hormone therapy: Qualitative comparison between decision-aid and control groups.

    Science.gov (United States)

    Gorawara-Bhat, Rita; O'Muircheartaigh, Siobhan; Mohile, Supriya; Dale, William

    2017-09-01

    To compare patients' attitudes towards recurrent prostate cancer (PCa) and starting hormone therapy (HT) treatment in two groups-Decision-Aid (DA) (intervention) and Standard-of-care (SoC) (Control). The present research was conducted at three academic clinics-two in the Midwest and one in the Northeast U.S. Patients with biochemical recurrence of PCa (n=26) and follow-up oncology visits meeting inclusion criteria were randomized to either the SoC or DA intervention group prior to their consultation. Analysts were blinded to group assignment. Semi-structured phone interviews with patients were conducted 1-week post consultation. Interviews were audio-taped and transcribed. Qualitative analytic techniques were used to extract salient themes and conduct a comparative analysis of the two groups. Four salient themes emerged-1) knowledge acquisition, 2) decision-making style, 3) decision-making about timing of HT, and 4) anxiety-coping mechanisms. A comparative analysis showed that patients receiving the DA intervention had a better comprehension of Prostate-specific antigen (PSA), an improved understanding of HT treatment implications, an external locus-of-control, participation in shared decision-making and, support-seeking for anxiety reduction. In contrast, SoC patients displayed worse comprehension of PSA testing and HT treatment implications, internal locus-of-control, unilateral involvement in knowledge-seeking and decision-making, and no support-seeking for anxiety-coping. The DA was more effective than the SoC group in helping PCa patients understand the full implications of PSA testing and treatment; motivating shared decision-making, and support-seeking for anxiety relief. DA DVD interventions can be a useful patient education tool for bringing higher quality decision-making to prostate cancer care. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Attitude, complications, ability of fasting and glycemic control in fasting Ramadan by children and adolescents with type 1 diabetes mellitus.

    Science.gov (United States)

    Deeb, Asma; Al Qahtani, Nabras; Akle, Mariette; Singh, Himanshi; Assadi, Rifah; Attia, Salima; Al Suwaidi, Hana; Hussain, Tara; Naglekerke, Nico

    2017-04-01

    Sick individuals and children are exempted from fasting Ramadan. Fasting by type 1 diabetes patients might predispose to acute complications. There are no guidelines on fasting safety or its impact on diabetes control in children and adolescents. We aim to assess patients' attitude towards fasting, frequency of complications and impact on glycemic control in children with type 1 diabetes. 65 children with type 1 diabetes were enrolled. The study involved 2 hospital visits. Questionnaires were filled in each visit and HbA1c was recorded. Log books indicating symptomatic hypoglycemia and hyperglycemia leading to breaking fast were obtained. Majority of subjects were willing to fast and 75% were encouraged by parents to do. 57% and 26% fasted more than half and all through the month respectively. 52% had, at least, one episode of hypoglycemia and 29% had hyperglycemia with one episode of ketoacidosis. All patients broke fast in response to symptomatic hypoglycemia/hyperglycemia. There was no significant difference between the frequency of complications in the pump or the Multiple Daily Injection (MDI) groups. Mean HbA1c increased from 70mmol/mol to 73mmol/mol. The difference was not statistically significant. Children and adolescents with type 1 diabetes are keen to fast Ramadan and they are able to fast a significant number of days. Hypoglycemia and hyperglycemia are not uncommon with no difference between Pump or in MDI users. Breaking fast on occurrence of complications makes fasting safe. Glycemic control might deteriorate during the month and the following Eid. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effects of a Lifestyle Modification Program on Knowledge, Attitude and Practice of Hypertensive Patients with Angioplasty: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Jafari, Fahimeh; Shahriari, Mohsen; Sabouhi, Fakhri; Khosravi Farsani, Alireza; Eghbali Babadi, Maryam

    2016-10-01

    Lack of knowledge, attitude and practice are some of the barriers of having a healthy lifestyle and controlling high blood pressure. This study aimed to determine the effectiveness of a lifestyle modification program on knowledge, attitude and practice of hypertensive patients with angioplasty. This study was a randomized controlled clinical trial conducted from November to April 2014 on 60 hypertensive patients with angioplasty in Shahid Chamran hospital of Isfahan, Iran. The samples were randomly assigned to two equal groups. Data collection was performed in three stages by a researcher-made questionnaire. The intervention plan was 6 education sessions and then follow up were done by phone call. The gathered data were analyzed via SPSS (V.20), using t-test, Chi-square, repeated measurement, and post hoc LSD test and ANOVA statistics. The mean score of knowledge, attitude and practice in the experimental group immediately after the intervention was 77.8±7.2, 88.3±6.4 and 86.2±6.5, respectively and one month after the intervention was 80.8±7.4, 91.1±3.5 and 92.5±2.2, respectively. But in the control group, the mean score of knowledge, attitude and practice immediately after the intervention (34.90±11.23, 61.11±6.28, and 38.64±7.15) and one month after the intervention was (38.64±7.15, 59.56±6.31 and 37.27±7.26. Lifestyle modification program can be effective in promoting the knowledge, attitude and practice of hypertensive patients with angioplasty. Nurses can use this program in their care provision programs for these patients. Trial Registration Number: IRCT2015062420912N3.

  16. Development of a Hardware-in-the-Loop Simulator for Control Moment Gyroscope-Based Attitude Control Systems

    Science.gov (United States)

    2015-12-01

    for each axis is 3 The modular nature of the flight computer control software (as discussed in...performed using the Setup Wizard tool in EPOS Studio; see Appendix A for a complete listing of the Setup Wizard settings used for the gimbal and momentum...1.00 rad/sec as compared with an approximately 15 percent reduction at ± 0.25 rad/sec). While the slight sinusoidal nature of the updated momentum

  17. Buddha as an eye opener: A link between prosocial attitude and attentional control

    Directory of Open Access Journals (Sweden)

    Lorenza S Colzato

    2010-09-01

    Full Text Available Increasing evidence suggests that religious practice induces systematic biases in attentional control. We used Navon’s global-local task to compare attentional bias in Taiwanese Buddhists and Taiwanese atheists; two groups brought up in the same country and culture and matched with respect to race, intelligence, sex, and age. Given the Buddhist emphasis on compassion for the physical and social environment, we expected a more global bias in Buddhist than in Atheist participants. In line with these expectations, Buddhists showed a larger global-precedence effect and increased interference from global distracters when processing local information. This pattern reinforces the idea that people's attentional processing style reflects biases rewarded by their religious beliefs.

  18. Smoking habits, awareness of risks, and attitude towards tobacco control policies among medical students in Lagos, Nigeria

    National Research Council Canada - National Science Library

    Michelle Dania; Obianuju Ozoh; Emmanuel Bandele

    2015-01-01

      Background: This study aimed to assess the prevalence of cigarette smoking among medical students, and to determine their level of knowledge regarding risk associated with cigarette smoking and their attitude...

  19. Public attitudes towards alcohol control policies in Scotland and England: Results from a mixed-methods study.

    Science.gov (United States)

    Li, Jessica; Lovatt, Melanie; Eadie, Douglas; Dobbie, Fiona; Meier, Petra; Holmes, John; Hastings, Gerard; MacKintosh, Anne Marie

    2017-03-01

    The harmful effects of heavy drinking on health have been widely reported, yet public opinion on governmental responsibility for alcohol control remains divided. This study examines UK public attitudes towards alcohol policies, identifies underlying dimensions that inform these, and relationships with perceived effectiveness. A cross-sectional mixed methods study involving a telephone survey of 3477 adult drinkers aged 16-65 and sixteen focus groups with 89 adult drinkers in Scotland and England was conducted between September 2012 and February 2013. Principal components analysis (PCA) was used to reduce twelve policy statements into underlying dimensions. These dimensions were used in linear regression models examining alcohol policy support by demographics, drinking behaviour and perceptions of UK drinking and government responsibility. Findings were supplemented with a thematic analysis of focus group transcripts. A majority of survey respondents supported all alcohol policies, although the level of support varied by type of policy. Greater enforcement of laws on under-age sales and more police patrolling the streets were strongly supported while support for pricing policies and restricting access to alcohol was more divided. PCA identified four main dimensions underlying support on policies: alcohol availability, provision of health information and treatment services, alcohol pricing, and greater law enforcement. Being female, older, a moderate drinker, and holding a belief that government should do more to reduce alcohol harms were associated with higher support on all policy dimensions. Focus group data revealed findings from the survey may have presented an overly positive level of support on all policies due to differences in perceived policy effectiveness. Perceived effectiveness can help inform underlying patterns of policy support and should be considered in conjunction with standard measures of support in future research on alcohol control policies

  20. Effects of a Lifestyle Modification Program on Knowledge, Attitude and Practice of Hypertensive Patients with Angioplasty: A Randomized Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Fahimeh Jafari

    2016-10-01

    Full Text Available Background: Lack of knowledge, attitude and practice are some of the barriers of having a healthy lifestyle and controlling high blood pressure. This study aimed to determine the effectiveness of a lifestyle modification program on knowledge, attitude and practice of hypertensive patients with angioplasty. Methods: This study was a randomizedcontrolledclinical trial conducted from November to April 2014 on 60 hypertensive patients with angioplasty in ShahidChamran hospital of Isfahan, Iran. The samples were randomly assigned to two equal groups. Data collection was performed in three stages by a researcher-made questionnaire. The intervention plan was 6 education sessions and then follow up were done by phone call. The gathered data were analyzed via SPSS (V.20, using t-test, Chi-square, repeated measurement, and post hoc LSD test andANOVA statistics. Results: The mean score of knowledge, attitude and practice in the experimental group immediately after the intervention was 77.8±7.2, 88.3±6.4 and 86.2±6.5, respectively and one month after the intervention was 80.8±7.4, 91.1±3.5 and 92.5±2.2, respectively. But in the control group, the mean score of knowledge, attitude and practice immediately after the intervention (34.90±11.23, 61.11±6.28, and 38.64±7.15 and one month after the intervention was (38.64±7.15, 59.56±6.31 and 37.27±7.26. Conclusion: Lifestyle modification program can be effective in promoting the knowledge, attitude and practice of hypertensive patients with angioplasty. Nurses can use this program in their care provision programs for these patients.

  1. Controle d'attitude d'un lanceur en phase atmospherique approche par applications gardiennes

    Science.gov (United States)

    Dubanchet, Vincent

    In a first phase, the modelling process underlines the presence of highly time varying parameters during the ascent, due to a fast mass variation along with propellant consumption. Linearizing the dynamical equations at six main flight instants yields linear time invariant models to be considered during control design. Each of them is to be stabilized by one control law, while respecting given specifications. The synthesis becomes even more complex when the bending modes are taken into account. Moreover, scheduling appears necessary to deal with the time variations. Indeed it is shown that no single gain setting is able to respect all the specifications along the trajectory. Furthermore, increasing complexity when modelling a whole launch vehicle pushes one to consider the model's errors and uncertainties. They represent a major issue in this study since it is asked to ensure the nominal performances in a robust fashion. Owing to their properties, guardian maps appear to be the most suitable tool to deal with such a problem of scheduling with robust performances. In light of this, the development of synthesis methods based on guardian maps is the main contribution of the project. It appears that actual state of the art in this field is focused on theoretical issues, whereas practical ones could be improved. Two approches are presented in the memoire. The first one is based on a graphical approach consisting in drawing the vanishing locus of guardian maps. A program using image analysis techniques is devised to check automatically which gain settings satisfy the constraints. The second one is based on an optimisation procedure involving guardian maps. Starting with the open loop system, the iterative process proposed ends up with a satisfactory gain setting for the closed-loop. These methods are tried and tested for the launch vehicle, with specifications from ASTRIUM-ST. Their practical application is motivated by the system complexity, the different kinds of

  2. Design of an attitude control system for spin-axis control of a 3U CubeSat

    Science.gov (United States)

    Westfall, Alexander J.

    This paper describes the design process of developing a spin-axis control system for a 3U CubeSat, a relatively small satellite. Design requires the CubeSat to de-spin after deployment and direct its antenna to track Earth nadir position. The one degree of freedom controller is developed for the TechEdSat, which is a CubeSat with a payload that allows for the assumption that rotation pitch and yaw rates are sufficiently close to zero. Satellite torqueing disturbances are modeled with reaction wheel noise for a more complete system analysis. Sensor noise is unmodeled. Frequency domain and time domain analyses are presented; the entire system bandwidth operates at 0.08 hertz with 43.2 decibels of gain and 67.7° of phase margin. During nominal operations, pointing accuracy with perfect state knowledge assumption maintains position with steady state error of 13.7 arc seconds and oscillates by 16.7 arc seconds at a rate of 0.7 mHertz. Artificial wheel noise is injected into the model causing the pointing accuracy to drop to +/- 15 arc seconds. Environmental disturbances are modeled extensively; the magnetic field torque is the worst disturbance, at 4.2e-7 Newton-meters. A 0.2 Amp˙m2 magnetorquer dumps the excess momentum every 7.75 hours and require 1.5 hours to complete. In the deployment simulation, a 1 rotation per minute spin is arrested with no angular offset in 60 seconds. Future plans include utilizing the model to build and fly a prototype reaction wheel on a future TechEdSat mission to verify modeled expectations.

  3. Knowledge, Self-Confidence and Attitudes towards Suicidal Patients at Emergency and Psychiatric Departments: A Randomised Controlled Trial of the Effects of an Educational Poster Campaign.

    Science.gov (United States)

    van Landschoot, Renate; Portzky, Gwendolyn; van Heeringen, Kees

    2017-03-14

    Educational posters are used to enhance knowledge, attitudes and self-confidence of patients. Little is known on their effectiveness for educating health care professionals. As these professionals may play an important role in suicide prevention, the effects of a poster and accompanying evaluation and triage guide on knowledge, self-confidence and attitudes regarding suicidal thoughts and behaviours, were studied in a multicentre cluster randomised controlled trial, involving staff from 39 emergency and 38 psychiatric departments throughout Flanders ( n = 1171). Structured self-report questionnaires assessed the knowledge, confidence and beliefs regarding suicidal behaviour management, and attitudes. Data were analysed through a Solomon four-group design, with random assignment to the different conditions. Baseline scores for knowledge and provider confidence were high. The poster and accompanying evaluation and triage guide did not have an effect on knowledge about suicide and self-confidence in suicidal behaviour management. However, the poster campaign appeared to be beneficial for attitudes towards suicidal patients, but only among staff from mental health departments that were assigned to the un-pretested condition. Given the limited effects of the poster campaign in the studied population with a relatively high baseline knowledge, the evaluation of this poster as part of a multimodal educational programme in a more heterogeneous sample of health care professionals is recommended.

  4. Attitude Control Tradeoff Study Between the Use of a Flexible Beam and a Tether Configuration for the Connection of Two Bodies in Orbit

    Science.gov (United States)

    Graff, S. H.

    1985-01-01

    Sometimes it is necessary to mount a payload remotely from the main body of a spacecraft or space station. The reasons for this vary from vibration isolation to avoidance of measurement contamination. For example the SP-100 project, which grew out of the increased interest in nuclear power in space for space stations and for deep space explorations, requires separation of the nuclear reactor from the user because of vibration, heat and radiation. The different attitude control problems for beam and tether configurations are discussed. The beam configuration uses a conservative design approach. The vibration, beam flexibility and deployment concerns are analyzed. The tether configuration offers some very attractive design features, but not without several thorny problems. These problems are analyzed. One configuration will be recommended for the main thrust of the SP-100 design effort based on attitude control considerations.

  5. Sexual risk attitudes and intentions of youth aged 12-14 years: survey comparisons of parent-teen prevention and control groups.

    Science.gov (United States)

    Lederman, Regina P; Chan, Wenyaw; Roberts-Gray, Cynthia

    2004-01-01

    In this study, the authors compared differences in sexual risk attitudes and intentions for three groups of youth (experimental program, n = 90; attention control, n = 80; and nonparticipant control, n = 634) aged 12-14 years. Two student groups participated with their parents in programs focused on strengthening family interaction and prevention of sexual risks, HIV, and adolescent pregnancy. Surveys assessed students' attitudes and intentions regarding early sexual and other health-risk behaviors, family interactions, and perceived parental disapproval of risk behaviors. The authors used general linear modeling to compare results. The experimental prevention program differentiated the total scores of the 3 groups (p group scored higher than the nonparticipant group on total scores (p < .01) and on students' intention to avoid sex (p < .01). The results suggest this novel educational program involving both parents and students offers a promising approach to HIV and teen pregnancy prevention.

  6. [Respiratory physicians' knowledge, attitude and practice of tobacco control and their smoking status in the city of Chongqing].

    Science.gov (United States)

    Peng, Dan-yi; Zhou, Jun-hao; Chen, Hong; Li, Rui; Li, Cen; Zhou, Hong-yu; Wang, Dao-xin; Wang, Chang-zheng

    2013-04-01

    To investigate the smoking status, knowledge of smoking hazards, attitude of tobacco control and skill of assisting smoking cessation in respiratory physicians in the city of Chongqing and therefore to provide references for their further participation in social tobacco control. With a self-designed questionnaire, a cross-sectional study was conducted on respiratory physicians of 8 hospitals in Chongqing, which were selected with stratified random sampling method. All the data were inputted with software Epidata 3.1 and were analyzed with SPSS 13.0. A total of 428 valid questionnaires were retrieved, with a valid rate of 95.1% (428/450). The total smoking rate was 12.4% (95%CI: 9.3% - 15.5%), with 7.4% in physicians of teaching hospitals, 8.13% in those of hospitals located in urban areas, and 19.0% in those of hospitals located in suburban district counties. The differences in smoking rates in the respiratory physicians among different hospitals showed statistical significance (χ(2) = 11.734, P = 0.014). The smoking rate of the male was higher than that of the female. Of the surveyed doctors, 80.14% had awareness that tobacco dependence was a neuropsychiatric disease characterized as nicotine addiction, while 34.8% claimed that they had no idea about quitting smoking drugs. Although all participants claimed that they knew the harm of secondhand smoke, 16.36% of them still had never come forward to prevent smoking behavior in hospitals. There was only 27.4% of the surveyed discouraging smoking behavior with the reason of unwillingness to breath in secondhand smoke, while 53.9% of the surveyed discouraged smoking behavior because of regulations of hospitals. Most of the surveyed did relatively well in routinely inquiring and recording the smoking status of patients, but only 27.1% of them had recommended specific quitting smoking methods to patients, and there were few successful cases in practice. The situations of smoking cessation assistance in hospitals located

  7. Misconceptions about HIV infection in Kinshasa (Democratic Republic of Congo): a case-control study on knowledge, attitudes and practices.

    Science.gov (United States)

    Carlos, Silvia; Martínez-González, Miguel Ángel; Burgueño, Eduardo; López-Del Burgo, Cristina; Ruíz-Canela, Miguel; Ndarabu, Adolphe; Tshilolo, Léon; Tshiswaka, Philomène; Labarga, Pablo; de Irala, Jokin

    2015-08-01

    To evaluate the prevalence of HIV-related misconceptions in an outpatient centre of Kinshasa (Democratic Republic of Congo) and analyse the association between these beliefs and HIV infection. A case-control study was carried out from December 2010 until June 2012. We assessed 1630 participants aged 15-49 attending a primary outpatient centre in Kinshasa: 762 HIV Voluntary Counselling and Testing attendees and 868 blood donors. A 59-item questionnaire about knowledge, attitudes and practice was administered during a face-to-face interview, followed by an HIV test. Cases and controls were respondents with a newly diagnosed HIV-positive or HIV-negative test, respectively. Unconditional logistic regression was used to analyse the association between misconceptions and HIV seropositivity. 274 cases and 1340 controls were recruited. Cases were more likely than controls to have a low socioeconomic status, no education, to be divorced/separated or widowed. An association was found between the following variables and HIV seropositivity: having a poor HIV knowledge (adjusted OR=2.79; 95% CI 1.43 to 5.45), not knowing a virus is the cause of AIDS (adjusted OR=2.03; 95% CI 1.38 to 2.98) and reporting more than three HIV-transmission-related misconceptions (adjusted OR=3.30; 95% CI 1.64 to 6.64), such as thinking an HIV-positive person cannot look healthy and that HIV is transmitted by sorcery, God's punishment, a kiss on the mouth, mosquitoes, coughs/sneezes or undercooked food. Despite having access to healthcare services, there are still many people in Kinshasa that have HIV-related misconceptions that increase their HIV risk. Our findings underscore the need for a culturally adapted and gender-orientated basic HIV information into Congolese HIV prevention programmes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Preliminary performance of a vertical-attitude takeoff and landing, supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system

    Science.gov (United States)

    Robins, A. W.; Beissner, F. L., Jr.; Domack, C. S.; Swanson, E. E.

    1985-01-01

    A performance study was made of a vertical attitude takeoff and landing (VATOL), supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system. Those characteristics considered were aerodynamics, weight, balance, and performance. Preliminary results indicate that high levels of supersonic aerodynamic performance can be achieved. Further, with the assumption of an advanced (1985 technology readiness) low bypass ratio turbofan engine and advanced structures, excellent mission performance capability is indicated.

  9. Predicting condom use attitudes, norms, and control beliefs in Hispanic problem behavior youth: the effects of family functioning and parent-adolescent communication about sex on condom use.

    Science.gov (United States)

    Malcolm, Shandey; Huang, Shi; Cordova, David; Freitas, Derek; Arzon, Margaret; Jimenez, Giselle Leon; Pantin, Hilda; Prado, Guillermo

    2013-08-01

    Hispanic problem behavior youth are at an increased risk of engaging in HIV risk behaviors, including low condom use. However, relatively little research has examined factors that affect condom use in this population. Although research indicates that family processes, such as higher levels of family functioning and open parent-adolescent communication about sex, and condom use attitudes, norms, and control beliefs as depicted by the theory of planned behavior have an effect on condom use behaviors, the combination of the two factors has received minimal attention. The purpose of this study was to examine the effect of family functioning on condom use intentions and behaviors through communication about sex and condom use attitudes, parental norms, and control beliefs. A cross-sectional study of 171 predominately male (73.1%) sexually active Hispanic problem behavior adolescents (mean age = 14.88 years) was conducted. Structural equation modeling was used to test the study hypothesis. Findings largely support the overall model and suggest that family functioning had an indirect effect on condom use intention and behavior through communication about sex, condom use attitudes, and control beliefs. Family functioning, however, did not have an indirect effect on condom use intention and behavior through communication about sex and parental norms. Implications for prevention science and future research are discussed.

  10. Job attitudes.

    Science.gov (United States)

    Judge, Timothy A; Kammeyer-Mueller, John D

    2012-01-01

    Job attitudes research is arguably the most venerable and popular topic in organizational psychology. This article surveys the field as it has been constituted in the past several years. Definitional issues are addressed first, in an attempt to clarify the nature, scope, and structure of job attitudes. The distinction between cognitive and affective bases of job attitudes has been an issue of debate, and recent research using within-persons designs has done much to inform this discussion. Recent research has also begun to reformulate the question of dispositional or situational influences on employee attitudes by addressing how these factors might work together to influence attitudes. Finally, there has also been a continual growth in research investigating how employee attitudes are related to a variety of behaviors at both the individual and aggregated level of analysis.

  11. Knowledge of HIV/AIDS, attitudes towards sexual risk behaviour and perceived behavioural control among college students in Botswana

    Directory of Open Access Journals (Sweden)

    Gabriel Faimau

    2016-12-01

    Full Text Available This study examines the knowledge of HIV/AIDS, attitudes towards risky sexual behaviour and perceived behavioural control among students in Botswana. Data were collected from 445 students randomly selected from the University of Botswana and Boitekanelo College. Hundred and seventy three males and 272 females participated in the study. The study established that although more than 90% of students correctly identified routes of HIV transmission, misconceptions regarding HIV/AIDS still exist. This includes the belief that people can be infected with HIV because of witchcraft and that only people who have sex with gay or homosexual partners can be infected with HIV. Majority of students were aware of various sexual risks. However, the percentage of students who indicated that “it is difficult to ask my partner to use a condom” was still relatively high (13.5% based on the assumption that students are supposed to know the consequences of sexual risky behaviour. It was also found that male students were 3.48 times more likely to negotiate sex than their female counterparts (OR = 3.48, 95% CI: 1.09 − 11.13 and students who were 18 years and below were more likely to negotiate sex than students above 18 years of age (OR = 2.78, 95% CI: 1.42 − 18.32. Christians are four times less likely to negotiate sex compared to non-Christians (OR = 0.219, 95% CI: 0.095 − 0.506. More than 80% of students were comfortable discussing HIV or sex and sexuality with their friends, boyfriends/girlfriends or partners but uncomfortable discussing the same issues with their parents.

  12. Smoking behaviour predicts tobacco control attitudes in a high smoking prevalence hospital: A cross-sectional study in a Portuguese teaching hospital prior to the national smoking ban

    Directory of Open Access Journals (Sweden)

    Aguiar Pedro

    2011-09-01

    Full Text Available Abstract Background Several studies have investigated attitudes to and compliance with smoking bans, but few have been conducted in healthcare settings and none in such a setting in Portugal. Portugal is of particular interest because the current ban is not in line with World Health Organization recommendations for a "100% smoke-free" policy. In November 2007, a Portuguese teaching-hospital surveyed smoking behaviour and tobacco control (TC attitudes before the national ban came into force in January 2008. Methods Questionnaire-based cross-sectional study, including all eligible staff. Sample: 52.9% of the 1, 112 staff; mean age 38.3 ± 9.9 years; 65.9% females. Smoking behaviour and TC attitudes and beliefs were the main outcomes. Bivariable analyses were conducted using chi-squared and MacNemar tests to compare categorical variables and Mann-Whitney tests to compare medians. Multilogistic regression (MLR was performed to identify factors associated with smoking status and TC attitudes. Results Smoking prevalence was 40.5% (95% CI: 33.6-47.4 in males, 23.5% (95% CI: 19.2-27.8 in females (p Conclusions Smoking prevalence was high, especially among the lower socio-economic groups. The findings showed a very high level of support for smoking bans, despite the pro-smoking environment. Most staff reported passive behaviour, despite high SHS exposure. This and the high smoking prevalence may contribute to low compliance with the ban and low participation on smoking cessation activities. Smoking behaviour had greater influence in TC attitudes than health professionals' education. Our study is the first in Portugal to identify potential predictors of non-compliance with the partial smoking ban, further emphasising the need for a 100% smoke-free policy, effective enforcement and public health education to ensure compliance and promote social norm change.

  13. Comparative study on the knowledge-attitude-belief and practice to tobacco control between Chinese and foreign medical students in Soochow University

    Directory of Open Access Journals (Sweden)

    Qiao-zhu ZUO

    2014-01-01

    Full Text Available Objective: Based on the survey of the knowledge-attitude-belief and practice to tobacco control between Chinese and foreign medical students in Soochow University, the authors intended to explore the current situation, differences and influencing factors of Chinese and foreign medical students, in order to provide a reference for tobacco control policies and measures set by the Medical College of Soochow University. Methods: By stratified sampling, we selected 200 Chinese medical students and 200 foreign medical students of Medical College in different grades and different majors, and adopted anonymous questionnaires to investigate. Results: The smoking rates of Chinese and foreign male medical students were 7.4%, 15.5% respectively , while female medical students' smoking rates were 0.0, 8.1% respectively. Foreign medical students’ daily smoking was mostly 4~10, which was significantly greater than the Chinese medical students (P<0.05); besides, the identification degree to the responsibilities and duties for smoking control of the professional medical staff were both higher. The influence of the different smoking rates between Chinese and foreign medical students was mainly ethnic background, and the influences of the different smoking behavior mainly depended on their knowledge and attitude towards tobacco control. Conclusion: There is a need for schools to adopt health education measure to promote the school tobacco control based on the differences of the knowledge-attitude-belief and practice to tobacco control between Chinese and Foreign Medical students. Help medical students to translate knowledge of tobacco control they have already mastered into belief, and further affect their behavior.

  14. Linking eating and weight control attitudes to relationship experiences: A large-scale survey of adolescent females.

    Science.gov (United States)

    Thomas, Rebekah L; Kelly, Adrian B; Chan, Gary C K; Williams, Joanne W

    2017-07-01

    To examine the extent to which family conflict, peer bullying and psychological distress account for eating and weight loss attitudes in adolescent females. This study examined the degree to which psychological distress mediated the association between family conflict and eating and weight loss attitudes, and the association of bullying and eating and weight loss attitudes. Females aged between 11 and 17 years (N = 5125) were recruited from schools in the State of Victoria (Australia). Key measures included psychological distress, family conflict, and bullying victimisation. A structural model showed good fit, and all predictors were significant. Psychological distress mediated the association between eating and weight loss attitudes, and family problems and bullying. Family conflict and peer bullying were associated with eating and weight loss attitudes and this association may occur via psychological distress. Early intervention programs may benefit from a focus on family and peer relationships. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  15. Investigating multiple components of attitude, subjective norm, and perceived control: an examination of the theory of planned behaviour in the exercise domain.

    Science.gov (United States)

    Rhodes, Ryan E; Courneya, Kerry S

    2003-03-01

    The presence of two subcomponents within each theory of planned behaviour (TPB) concept of attitude (affective and instrumental), subjective norm (injunctive and descriptive), and PBC (self-efficacy and controllability) has been widely supported. However, research has not examined whether the commonality of variance between these components (i.e. a general factor) or the specificity of variance within the subcomponents influences intention and behaviour. Therefore, the purpose of this study was to examine the optimal conceptualization of either two subcomponents or a general common factor for each TPB concept within an omnibus model. Further, to test whether conceptualizations may differ by population even within the same behavioural domain, we examined these research questions with 300 undergraduates (M age = 20) and 272 cancer survivors (M age = 61) for exercise behaviour. Results identified that a general subjective norm factor was an optimal predictive conceptualization over two separate injunctive and descriptive norm components. In contrast, a specific self-efficacy component, and not controllability or a general factor of PBC, predicted intention optimally for both samples. Finally, optimal models of attitude differed between the populations, with a general factor best predicting intention for undergraduates but only affective attitude influencing intention for cancer survivors. The findings of these studies underscore the possibility for optimal tailored interventions based on population and behaviour. Finally, a discussion of the theoretical ambiguity of the PBC concept led to suggestions for future research and possible re-conceptualization.

  16. The impact of health education on the knowledge, attitudes and practices of a rural community with regards to schistosomiasis control using a plant molluscicide, Phytolacca dodecandra.

    Science.gov (United States)

    Gwatirisa, P R; Ndamba, J; Nyazema, N Z

    1999-04-01

    To determine the impact of health education on knowledge, attitudes and practices (KAP) with regards to use of a plant molluscicide in snail control. Repeat cross sectional survey. Chiweshe communal lands. Males and females--age range 13 to 87 years. Changes in: KAP after health education, water usage pattern, water contact behaviour, willingness to participate in use of P. dodecandra. A high proportion of the community indicated prior knowledge of schistosomiasis during both knowledge, attitudes and practices (KAP) surveys. In the follow up KAP survey changes in the community's water contact behaviour as well as their practices in relation to sanitation were reported. The involvement of the community in the application of P. dodecandra during the course of the study ensured continued support and participation of the community. This was evidenced in the follow up survey when it was apparent that the community's attitude towards schistosomiasis had been influenced by the different activities that had taken place. Changes in the community's KAP with regards to schistosomiasis control, can be interpreted as an indication of the impact of the health education delivered during the course of the study. Health education should, therefore, precede programmes that require full participation of the community, as this enables the community to make informed decisions regarding their participation.

  17. Knowledge, attitude and practices in relation to prevention and control of schistosomiasis infection in Mwea Kirinyaga county, Kenya

    Directory of Open Access Journals (Sweden)

    J Mwai

    2016-08-01

    Full Text Available Abstract Background Schistosomiasis remains a major public health problem in Kenya. Inadequate knowledge, attitudes and practices (KAP on causative factors are some of the critical factors for the increased prevalence. The study assessed KAP on the control and prevention of schistosomiasis infection in Mwea division, Kirinyaga County-Kenya. Four hundred and sixty five house-hold heads were enrolled in this study by use of simple random sampling technique. Methods The study employed an analytical descriptive cross sectional design utilizing both quantitative and qualitative data collection methods. A pretested structured questionnaire, Focus Group Discusions (FGDs and Key Informant Interviews (KII guides were used for data collection. Descriptive statistics and Chi square tests and Fisher’s exact tests were computed where applicable. Data from the FGDs and KIIs were analyzed using NUID.IST NUIRO.6 software. Results Significant associations between knowledge and demographic factors i.e. age (p = 0.011, education level (p = 0.046, were reported. Handwashing after visiting the toilet (p = 0.001, having a toilet facility at home (p = 0.014; raring animals at home (p = 0.031, households being affected by floods (p = 0.005 and frequency of visits to the paddies (p = 0.037 had a significant association with respondents practices and schistosomiasis infection. Further significance was reported on households being affected by floods during the rainy season (p < 0.001, sources of water in a household (p < 0.047 and having a temporary water body in the area (p = 0.024 with increase in schistosomiasis infection. Results revealed that respondents practices were not significantly associated with gender (p = 0.060, marital status (p = 0.71, wearing of protective gear (p = 0.142 and working on the paddies (p = 0.144. Conclusions This study reveals that knowledge about the cause, transmission, symptoms and

  18. Case-based e-learning to improve the attitude of medical students towards occupational health, a randomised controlled trial

    NARCIS (Netherlands)

    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.

    2012-01-01

    Objectives 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

  19. Physician attitudes toward dissemination of optical spectroscopy devices for cervical cancer control: an industrial-academic collaborative study.

    Science.gov (United States)

    Shinn, Eileen; Qazi, Usman; Gera, Shalini; Brodovsky, Joan; Simpson, Jessica; Follen, Michele; Basen-Engquist, Karen; Macaulay, Calum

    2012-02-01

    Optical spectroscopy has been studied for biologic plausibility, technical efficacy, clinical effectiveness, patient satisfaction, and cost-effectiveness. We sought to identify health care provider attitudes or practices that might act as barriers or to the dissemination of this new technology. Through an academic-industrial partnership, we conducted a series of focus groups to examine physician barriers to optical diagnosis. The study was conducted in 2 stages. First, a pilot group of 10 physicians (8 obstetrician gynecologists and 2 family practitioners) was randomly selected from 8 regions of the United States and each physician was interviewed individually. Physicians were presented with the results of a large trial (N = 980) testing the accuracy of a spectroscopy-based device in the detection of cervical neoplasia. They were also shown a prototype of the device and were given a period of time to ask questions and receive answers regarding the device. They were also asked to provide feedback on a questionnaire that was then revised and presented to 3 larger focus groups (n = 13, 15, and 17 for a total N = 45). The larger focus groups were conducted during national scientific meetings with 20 obstetrician gynecologists and 25 primary care physicians (family practitioners and internists). When asked about the dissemination potential of the new cervical screening technology, all study groups tended to rely on established clinical guidelines from their respective professional societies with regard to the screening and diagnosis of cervical cancer. In addition, study participants consistently agreed that real-time spectroscopy would be viewed positively by their patients. Participants were positive about the new technology's potential as an adjunct to colposcopy and agreed that the improved accuracy would result in reduced health care costs (due to decreased biopsies and decreased visits). Although all participants saw the potential of real-time diagnosis, there

  20. Effectiveness of health education intervention in improving knowledge, attitude, and practices regarding Tuberculosis among HIV patients in General Hospital Minna, Nigeria - A randomized control trial.

    Science.gov (United States)

    Bisallah, Chindo Ibrahim; Rampal, Lekhraj; Lye, Munn-Sann; Mohd Sidik, Sherina; Ibrahim, Normala; Iliyasu, Zubairu; Onyilo, Michael Ochigbo

    2018-01-01

    The risk of development of active TB in HIV-infected individuals is 20-37 times higher than those that are HIV negative. Poor knowledge of TB amongst people living with HIV has been associated with high transmission. To determine the effectiveness of a new health education intervention module in improving knowledge, attitude, and practice (KAP) regarding tuberculosis among HIV patients in General Hospital Minna, Nigeria. A randomized control trial was carried out from July 2015 to June 2017. A random number generating program was used to allocate 226 respondents into 2 groups. The intervention group received health education regarding tuberculosis using the developed module. The control group received the normal services provided for HIV patients. Data were collected from December 2015 to September 2016 at baseline, immediate post intervention, three, six and nine months. The outcome measures were knowledge, attitude, and practice. There was no significant difference with respect to socio-demographic characteristics, KAP of the respondents in the intervention and control group at baseline. However, there was significant improvement in knowledge in the intervention group compared to the control group, group main effect (F = (1,218) = 665.889, p = 0.001, partial ἠ2 = 0.753, d = 5.4); time (F = (3.605, 218) = 52.046, p = 0.001, partial ἠ2 = 0.193, d = 1.52) and interaction between group with time (F = (3.605, 218) = 34.028, p = 0.001, partial ἠ2 = 0.135, d = 1.23). Likewise, there was significant improvement in attitude, group main effect (p = 0.001, d = 1.26) and time (p = 0.001, p, d = 0.65). Similarly, there was improvement in practice, group main effect, time, and interaction of group with time (p < 0.05). The health education intervention program was effective in improving KAP regarding tuberculosis among HIV patients.

  1. The influence of patient attitude toward massage on pressure pain sensitivity and immune system after application of myofascial release in breast cancer survivors: a randomized, controlled crossover study.

    Science.gov (United States)

    Fernández-Lao, Carolina; Cantarero-Villanueva, Irene; Díaz-Rodríguez, Lourdes; Fernández-de-las-Peñas, César; Sánchez-Salado, Carmen; Arroyo-Morales, Manuel

    2012-02-01

    The purpose of this study was to evaluate the influence of patient's attitudes toward massage on pressure pain sensitivity and the immune effects of myofascial release in breast cancer survivors (BCS). Twenty BCS participated. They presented to the laboratory at the same time of the day on 2 occasions separated by 2 weeks. At each session, they received either a myofascial release technique or control (special attention) intervention. Salivary flow rate, cortisol and immunoglobulin A (IgA) concentrations, and α-amylase activity were obtained before and immediately after intervention from saliva samples. Pressure pain thresholds (PPT) over the cervical spine and temporalis muscle were assessed bilaterally. The attitude toward massage (ATOM) scale was collected before the first session in all BCS. The analysis of covariance revealed a significant intervention × time interaction for salivary flow rate (P = .010), but not α-amylase (P = .111), IgA (P = .655), and cortisol (P = .363) in favor of the experimental group: BCS exhibited an increase of salivary flow rate after myofascial release intervention. When the ATOM scale was included in the analysis, significant influence on IgA (P = .001) was found: BCS with positive attitude had a significant increase in IgA (P > .05). The analysis of covariance did not find a significant intervention × time interaction for PPT over the cervical spine or temporalis muscle, with no effect of ATOM scales for PPT (P > .05). The current study suggests that myofascial release may lead to an immediate increase in salivary flow rate in BCS with cancer-related fatigue. We also found that the effect of myofascial release on immune function was modulated by a positive patient's attitude toward massage. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  2. Evaluation of Chronic Disease Prevention and Control Public Service Advertisement on the Awareness and Attitude Change among Urban Population in Chongqing, China: A Cross-Sectional Study.

    Science.gov (United States)

    Wu, Tingting; Hu, Ping; Huang, Hao; Wu, Chengbin; Fu, Zhirong; Du, Lei; Xu, Xianglong; Shi, Zumin; Zhao, Yong

    2017-12-05

    The aim of this study is to evaluate the influence of public service advertising on the awareness and attitude of Chongqing urban citizens. The theme of the public service advertisement launched in Chongqing was chronic disease prevention and control. A self-designed questionnaire was used in an outdoor intercept survey to collect information about the perception of citizens toward the effect of the advertisement on awareness and attitude situation. Respondents had good knowledge of chronic disease (17.11 ± 3.23, total score: 23), but only 58.4% of participants thought cancer is one type of chronic disease. The awareness of cancer as a chronic disease among the group who had seen this advertisement (63.6%) was higher than that of the group who had not seen the advertisement (56.5%) (p = 0.046). The attitude of respondents was good after watching the advertisement, approximately 77.4% of respondents attempted to remind their family and friends to prevent chronic diseases, roughly. 78.2% tried to persuade their family and friends to change their unhealthy lifestyle habits, and 84.7% of participants reported that the advertising increased the possibility of their own future lifestyle change. There was minimal change of awareness of the participants who saw the advertisement. This study did not show significant differences on chronic disease related knowledge between the participants who have seen the advertisement and who have not seen the advertisement. The public service advertisement may help participants improve the attitude of future behavior change. Further researches combining the sustained intervention and support through clinical and community health programs media campaigns are needed to support public health.

  3. Evaluation of Chronic Disease Prevention and Control Public Service Advertisement on the Awareness and Attitude Change among Urban Population in Chongqing, China: A Cross-Sectional Study

    Science.gov (United States)

    Wu, Tingting; Hu, Ping; Huang, Hao; Wu, Chengbin; Fu, Zhirong; Du, Lei; Zhao, Yong

    2017-01-01

    The aim of this study is to evaluate the influence of public service advertising on the awareness and attitude of Chongqing urban citizens. The theme of the public service advertisement launched in Chongqing was chronic disease prevention and control. A self-designed questionnaire was used in an outdoor intercept survey to collect information about the perception of citizens toward the effect of the advertisement on awareness and attitude situation. Respondents had good knowledge of chronic disease (17.11 ± 3.23, total score: 23), but only 58.4% of participants thought cancer is one type of chronic disease. The awareness of cancer as a chronic disease among the group who had seen this advertisement (63.6%) was higher than that of the group who had not seen the advertisement (56.5%) (p = 0.046). The attitude of respondents was good after watching the advertisement, approximately 77.4% of respondents attempted to remind their family and friends to prevent chronic diseases, roughly. 78.2% tried to persuade their family and friends to change their unhealthy lifestyle habits, and 84.7% of participants reported that the advertising increased the possibility of their own future lifestyle change. There was minimal change of awareness of the participants who saw the advertisement. This study did not show significant differences on chronic disease related knowledge between the participants who have seen the advertisement and who have not seen the advertisement. The public service advertisement may help participants improve the attitude of future behavior change. Further researches combining the sustained intervention and support through clinical and community health programs media campaigns are needed to support public health. PMID:29206192

  4. Knowledge, attitude and practice of bankers in Lagos Island local government area regarding healthy lifestyle in the prevention and control of non-communicable diseases

    Directory of Open Access Journals (Sweden)

    A B Adelowo

    2013-01-01

    Full Text Available Background and Objective: Non - communicable diseases (NCDs are the leading cause of morbidity and mortality in many developed and developing countries. Nigeria is experiencing an epidemiological transition with a double burden of communicable and non communicable diseases. This study was carried out to assess the knowledge, attitude and practice of bankers in Lagos Island Local Government Area on healthy lifestyle in relation to the prevention and control of NCDs. Material and Methods: Cross sectional descriptive design was employed. Multistage sampling technique was used to collect information from 260 consenting bankers using pretested, interviewer administered questionnaires. The questionnaire collected information on biodata, knowledge, attitude and practice. Data obtained was analyzed using Epi info version 3.5.3 Results: The mean age of 260 the respondents was 33.5 ± 5.7 years. Only 26.9% had good knowledge of healthy lifestyle while 87.3% had good attitude towards healthy lifestyle. Only 9.7% consumed healthy diet, while majority 88.0% and 72.7% had good practice regarding tobacco smoking and alcohol consumption respectively. Gender was a significant predictor of alcohol use, 55.8% of the study population engaged in adequate physical activity, while very few (3.8% of the respondents engaged in healthy lifestyle. Conclusion: Although the bankers had good attitude towards healthy lifestyle, their knowledge and practice of healthy living was poor. The management of every bank should invest in periodic health promotion and wellness programs that will promote all the components of healthy living for their employees.

  5. Impact of an infection-control program on nurses' knowledge and attitude in pediatric intensive care units at Cairo University hospitals.

    Science.gov (United States)

    Galal, Yasmine S; Labib, John R; Abouelhamd, Walaa A

    2014-04-01

    Healthcare-associated infection is a prominent problem among patients in pediatric intensive care units (PICU) as it could result in significant morbidity, prolonged hospitalization, and increase in medical care costs. The role of nurses is extremely important in preventing hazards and sequela of healthcare-associated infections. The aim of this study was to assess the effect of a health education program regarding infection-control measures on nurses' knowledge and attitude in PICUs at Cairo University hospitals. This was a pre-post test interventional study in which a convenient sample of 125 nurses was taken from the nursing staff in different PICUs at Cairo University hospitals. The study took place in three phases. In the first phase, the nursing staff's knowledge, attitude and practice concerning infection-control measures were tested using a self-administered pretested questionnaire and an observation checklist. The second phase included health education sessions in the form of powerpoint and video presentations; and in the third phase the nurses' knowledge and attitude on infection-control measures were reassessed. A significantly higher level of knowledge was revealed in the postintervention phase as compared with the preintervention phase with regards to the types of nosocomial infections (94.4 vs. 76.8%, PNurses in the postintervention phase had significantly more knowledge about the types of hand washing (99.2 vs. 91.2%, P=0.006). A significantly higher percent of nurses in the postintervention phase knew the importance of avoiding recapping syringes (72.8 vs. 34.4%, Pattitude scores were revealed in the postintervention phase as compared with the preintervention one (Pnurses in the neonatal intensive care unit at the Japanese Hospital (88%), whereas it was the lowest in the emergency pediatric unit (65%). There is scope for improvement in knowledge and attitude after educational program was offered to the nursing staff. Educational training programs

  6. Evaluation of an Online Campaign for Promoting Help-Seeking Attitudes for Depression Using a Facebook Advertisement: An Online Randomized Controlled Experiment.

    Science.gov (United States)

    Hui, Alison; Wong, Paul Wai-Ching; Fu, King-Wa

    2015-01-01

    A depression-awareness campaign delivered through the Internet has been recommended as a public health approach that would enhance mental health literacy and encourage help-seeking attitudes. However, the outcomes of such a campaign remain understudied. The main aim of this study was to evaluate the effectiveness of an online depression awareness campaign, which was informed by the theory of planned behavior, to encourage help-seeking attitudes for depression and to enhance mental health literacy in Hong Kong. The second aim was to examine click-through behaviors by varying the affective facial expressions of people in the Facebook advertisements. Potential participants were recruited through Facebook advertisements, using either a happy or sad face illustration. Volunteer participants registered for the study by clicking on the advertisement and were invited to leave their personal email addresses to receive educational content about depression. The participants were randomly assigned into two groups (campaign or control), and over a four consecutive week period, received either the campaign material or official information developed by the Hospital Authority in Hong Kong. Pretests and posttests were conducted before and after the campaign to measure the differences in help-seeking attitudes and mental health literacy among the campaign and control groups. Of the 199 participants that registered and completed the pretest, 116 (55 campaign and 62 control) completed the campaign and the posttest. At the posttest, we found no significant changes in help-seeking attitudes between the campaign and control groups, but the campaign group participants demonstrated a statistically significant improvement in mental health literacy (P=.031) and a higher willingness to access additional information (PFacebook advertisement attracted more click-throughs by users into the website than did the sad face advertisement (P=.03). The present study provides evidence that an online

  7. The influence of perceived behaviour control, attitude and empowerment on reported condom use and intention to use condoms among adolescents in rural Tanzania.

    Science.gov (United States)

    Kalolo, Albino; Kibusi, Stephen Matthew

    2015-11-13

    Despite the declining trends of Human immunodeficiency virus (HIV) infection in Sub-Saharan Africa (SSA), unsafe sexual behaviours among adolescents still represent a public health challenge. It is important to understand factors acting at different levels to influence sexual behaviour among adolescents. This study examined the influence of perceived behaviour control, subjective norms, attitudes and empowerment on intention to use condoms and reported use of condoms among adolescents in rural Tanzania. We used a questionnaire to collect data from 403 adolescents aged 14 through 19 years from nine randomly selected secondary schools in the Newala district located in the Southern part of Tanzania. The self-administered questionnaire collected information on sexual practices and factors such as attitudes, subjective norms, perceived behaviour control and empowerment. Binary logistic regression was performed to identify factors associated with intention to use and reported use of condoms. Sexually active adolescents constituted 40.6 % of the sample, among them 49.7 % did not use a condom at last sexual intercourse and 49.8 % had multiple sex partners. Many (85 %) of sexually active respondents had their sexual debut between the ages of 14 to 17 years. Girls became sexually active earlier than boys. Perceived behaviour control predicted intentions to use condoms (AOR = 3.059, 95 % CI 1.324-7.065), thus demonstrating its importance in the decision to use a condom. Empowerment (odds ratio = 3.694, 95 % CI 1.295-10.535) and a positive attitude (AOR = 3.484, 95 % CI 1.132-10.72) predicted reported condom use, thus turning the decision to actions. Subjective norms had only indirect effects on intention and reported use of condoms. The findings suggest that unsafe sex practices are prevalent among school adolescents in rural areas of Tanzania. Perceived behaviour control and positive attitudes predict intensions to use condoms whereas empowerment

  8. Evaluation of an Online Campaign for Promoting Help-Seeking Attitudes for Depression Using a Facebook Advertisement: An Online Randomized Controlled Experiment

    Science.gov (United States)

    2015-01-01

    Background A depression-awareness campaign delivered through the Internet has been recommended as a public health approach that would enhance mental health literacy and encourage help-seeking attitudes. However, the outcomes of such a campaign remain understudied. Objective The main aim of this study was to evaluate the effectiveness of an online depression awareness campaign, which was informed by the theory of planned behavior, to encourage help-seeking attitudes for depression and to enhance mental health literacy in Hong Kong. The second aim was to examine click-through behaviors by varying the affective facial expressions of people in the Facebook advertisements. Methods Potential participants were recruited through Facebook advertisements, using either a happy or sad face illustration. Volunteer participants registered for the study by clicking on the advertisement and were invited to leave their personal email addresses to receive educational content about depression. The participants were randomly assigned into two groups (campaign or control), and over a four consecutive week period, received either the campaign material or official information developed by the Hospital Authority in Hong Kong. Pretests and posttests were conducted before and after the campaign to measure the differences in help-seeking attitudes and mental health literacy among the campaign and control groups. Results Of the 199 participants that registered and completed the pretest, 116 (55 campaign and 62 control) completed the campaign and the posttest. At the posttest, we found no significant changes in help-seeking attitudes between the campaign and control groups, but the campaign group participants demonstrated a statistically significant improvement in mental health literacy (P=.031) and a higher willingness to access additional information (Padvertisement attracted more click-throughs by users into the website than did the sad face advertisement (P=.03). Conclusions The present

  9. Personalising care of adults with asthma from Asia: a modified e-Dephi consensus study to inform management tailored to attitude and control profiles.

    Science.gov (United States)

    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.

  10. Impact of a nursing education program about caring for patients in Japan with malignant pleural mesothelioma on nurses' knowledge, difficulties and attitude: a randomized control trial.

    Science.gov (United States)

    Nagamatsu, Yasuko; Natori, Yuji; Yanai, Haruo; Horiuchi, Shigeko

    2014-07-01

    In Japan nursing care lags behind the growing population of patients with malignant pleural mesothelioma. This study evaluated an educational program for nurses about caring for patients with malignant pleural mesothelioma in Japan. In this randomized controlled study relative to care for malignant pleural mesothelioma, Knowledge, Difficulties and Attitude were measured at baseline, at post-test and at follow-up one month later. The two-day program with a half-day follow-up program included lectures, group work, role-playing and group discussion. 188 participants were randomly assigned to the intervention group (program, n=96) and control group (n=92; self-study by a similar content handbook). At baseline the groups showed no statistical differences in Knowledge (p=0.921), Difficulty (p=0.458) and Attitude (p=0.922). Completing the study were 177 participants yielding 88 in the intervention group and 89 in the control group. Human rights and privacy of participants were protected. The Knowledge score was significantly higher in the intervention post-test (t=14.03, p=0.000) and follow-up test (t=8.98, p=0.000). Difficulty score was significantly lower in the intervention at post-test (t=-3.41, p=0.001) and follow-up test (t=-3.70, p=0.000). The Attitude score was significantly higher in the intervention post-test (t=7.11, p=0.000) and follow-up test (t=4.54, p=0.000). The two-way analysis of variance with repeated measures on time showed an interaction between time and group; the subsequent simple main effect test found significant differences (p=0.000-0.001) between groups for after-program and at follow-up and a significant difference (p=0.000) in time only within the intervention group. The educational program was effective in improving the nurses' knowledge and attitude toward malignant pleural mesothelioma care and decreasing the difficulty in MPM care, therefore this program has potential for nurses' in-service education throughout Japan. Copyright © 2014

  11. Method and apparatus for rate integration supplement for attitude referencing with quaternion differencing

    Science.gov (United States)

    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.

  12. Depression and life satisfaction in aging polio survivors versus age-matched controls: relation to postpolio syndrome, family functioning, and attitude toward disability.

    Science.gov (United States)

    Kemp, B J; Adams, B M; Campbell, M L

    1997-02-01

    To compare depressive symptoms and life satisfaction in aging polio survivors with age-matched controls and to relate these outcomes to scores to psychosocial and disability-related variables. A planned medical, functional, and psychosocial study with multivariate analyses. A large, urban rehabilitation center. A volunteer sample of 121 polio survivors and an age-matched control group of 60 people with similar sociodemographic backgrounds. Depression as measured by the Geriatric Depression Scale and an 11-item life satisfaction scale. The prevalence of depressive disorders was not significantly different in the two groups, although the postpolio group tended to have more symptomatology and an overall depressive disorder prevalence of 28%. Some life satisfaction scale scores were significantly lower in the postpolio group, especially those concerned with health. People with postpolio syndrome scored significantly higher on depression scales and lower on some life satisfaction scales than people with a history of polio but without postpolio syndrome. Several psychosocial variables, most notably family functioning and attitude toward disability, helped to mediate this effect. Among people with significant depression, there was little, evidence of adequate treatment in the community. Postpolio by itself does not relate to higher depression scores or lower life satisfaction. Postpolio syndrome has some relation to depression, but family functioning and attitude toward disability are more important. There is a need for better community-based psychological services.

  13. A recurrent neural-network-based sensor and actuator fault detection and isolation for nonlinear systems with application to the satellite's attitude control subsystem.

    Science.gov (United States)

    Talebi, H A; Khorasani, K; Tafazoli, S

    2009-01-01

    This paper presents a robust fault detection and isolation (FDI) scheme for a general class of nonlinear systems using a neural-network-based observer strategy. Both actuator and sensor faults are considered. The nonlinear system considered is subject to both state and sensor uncertainties and disturbances. Two recurrent neural networks are employed to identify general unknown actuator and sensor faults, respectively. The neural network weights are updated according to a modified backpropagation scheme. Unlike many previous methods developed in the literature, our proposed FDI scheme does not rely on availability of full state measurements. The stability of the overall FDI scheme in presence of unknown sensor and actuator faults as well as plant and sensor noise and uncertainties is shown by using the Lyapunov's direct method. The stability analysis developed requires no restrictive assumptions on the system and/or the FDI algorithm. Magnetorquer-type actuators and magnetometer-type sensors that are commonly employed in the attitude control subsystem (ACS) of low-Earth orbit (LEO) satellites for attitude determination and control are considered in our case studies. The effectiveness and capabilities of our proposed fault diagnosis strategy are demonstrated and validated through extensive simulation studies.

  14. Got an Attitude Problem?

    Science.gov (United States)

    1999-01-01

    Through a Small Business Innovation Research grant from NASA's Goddard Space Flight Center, Servo Corporation of America, Inc. built its Mini-Dual Sensor to provide attitude control for Earth-orbiting unmanned satellites. The sensor is an Earth horizon sensor that provides higher accuracy through the use of pyroelectric arrays and a patented radiance compensation scheme.This sensor gathers data with two pairs of lithium tantalate pyroelectric arrays that are positioned 90 degrees apart in the imaging plane. The Mini-Dual Earth Sensor is a high-accuracy sensor that could be used for attitude determination in future space missions.

  15. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania

    Science.gov (United States)

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

  16. Platform attitude data acquisition system

    Digital Repository Service at National Institute of Oceanography (India)

    Afzulpurkar, S.

    A system for automatic acquisition of underwater platform attitude data has been designed, developed and tested in the laboratory. This is a micro controller based system interfacing dual axis inclinometer, high-resolution digital compass...

  17. Controlled randomized clinical trial of spirituality integrated psychotherapy, cognitive-behavioral therapy and medication intervention on depressive symptoms and dysfunctional attitudes in patients with dysthymic disorder

    Science.gov (United States)

    Ebrahimi, Amrollah; Neshatdoost, Hamid Taher; Mousavi, Seyed Ghafur; Asadollahi, Ghorban Ali; Nasiri, Hamid

    2013-01-01

    Background: Due to the controversy over efficacy of cognitive-behavioral therapy for chronic depression, recently, there has been an increasingly tendency toward therapeutic methods based on the cultural and spiritual approaches. The aim of this research was to compare efficacy of spiritual integrated psychotherapy (SIPT) and cognitive-behavioral therapy (CBT) on the intensity of depression symptoms and dysfunctional attitudes of patients with dysthymic disorder. Materials and Methods: This study had a mixed qualitative and quantitative design. In the first phase, SIPT model was prepared and, in the second phase, a double-blind random clinical trial was performed. Sixty-two patients with dysthymic disorder were selected from several centers include Nour and Alzahra Medical Center, Counseling Centers of Isfahan University of Medical Sciences and Goldis in Isfahan. The participants were randomly assigned to three experimental groups and one control group. The first group received 8 sessions treatment of SIPT, second groups also had 8 sessions of cognitive-behavioral therapy, which was specific to dysthymic disorder and third group were under antidepressant treatment. Beck depression inventory and dysfunctional attitudes scale were used to evaluate all the participants in four measurement stages. The data were analyzed using MANCOVA repeated measure method. Results: The results revealed that SIPT had more efficacy than medication based on both scales (P < 0.01); however, it was not different from CBT. SIPT was more effective on the modification of dysfunctional attitudes compared with CBT and medication (P < 0.05). Conclusion: These findings supported the efficacy of psychotherapy enriched with cultural capacities and religious teachings. PMID:24516853

  18. Knowledge, attitudes and preventive behaviors related to dengue vector breeding control measures among adults in communities of Vientiane, capital of the Lao PDR.

    Science.gov (United States)

    Sayavong, Chanthalay; Chompikul, Jiraporn; Wongsawass, Somsak; Rattanapan, Cheerwit

    2015-01-01

    This research aimed to determine the knowledge, attitudes and preventive behaviors (KAP) of adults in relation to dengue vector control measures in the communities of Vientiane, the capital of the Lao PDR. A total of 207 respondents were actively participating in this cross-sectional descriptive study in 2011. Representatives of households were interviewed face-to-face by six trained interviewers using a structured questionnaire. KAP reliabilities of 0.89, 0.91 and 0.95 were reported in the pilot sample of 30 cases. The associations between each independent variable and prevention behavior were tested with chi-square tests. Multiple logistic regression was used to determine the factors that were significantly associated with preventive behavior while controlling for the other variables. The results revealed that 51.69% of the respondents had a high level of knowledge. More than 94% of the respondents knew that dengue fever is a dangerous communicable disease and that dengue fever is transmitted from person to person via mosquitoes. More than half (56.52%) of the participants had positive attitudes toward vector control measures, and 52.17% exhibited a high level of preventive behavior in terms of dengue vector control measures. Preventive behaviors were significantly associated with information provided from sources that included health personnel (p = 0.038) and heads of villages (p=0.031) and with knowledge levels (p < 0.001). This study suggests that proactive health education through appropriated mass media and community clean-up campaigns should strengthen and encourage community participation, particularly in terms of addressing mosquito larvae in overlooked places, such as the participants' own homes, for example, in flower vases and ant traps. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  19. Attitudes toward HIV-infected individuals and infection control practices among a group of dentists in Mexico City--a 1999 update of the 1992 survey.

    Science.gov (United States)

    Maupomé, Gerardo; Borges-Yáñez, S Aída; Díez-De-Bonilla, F Javier; Irigoyen-Camacho, María Esther

    2002-02-01

    The teaching of infection control (IC) was introduced at dental schools in Mexico during the 1990s. A 1992 survey indicated that some dentists had limited access to current IC standards. Deficient knowledge of bloodborne pathogens may influence dentists' attitudes about infected individuals and reduce compliance with IC recommendations. To update the 1992 appraisal of attitudes about persons infected with HIV or the hepatitis B virus (HBV) and IC knowledge and practices in a nonrepresentative sample of dentists in Mexico City. One hundred eighty dentists were interviewed in 1999 (response rate, 84.1%) with the same methods used in 1992. Seventy-nine percent of respondents perceived the risk of HIV infection as "considerable" to "very strong." The risk of HBV infection was considered higher than that of HIV. Only 32% of respondents had not been immunized against HBV. Reported use of personal protective equipment remained high. Dry heat was the preferred method for sterilization in 1992, but by 1999 it had been displaced by steam under pressure. Reported preference for more effective disinfectants was also evident overall. We found certain improvements in IC knowledge and practices between 1992 and 1999, and the results suggest targets for educational and regulatory efforts that are needed to promote better adherence to current IC standards.

  20. Max Launch Abort System (MLAS) Pad Abort Test Vehicle (PATV) II Attitude Control System (ACS) Integration and Pressurization Subsystem Dynamic Random Vibration Analysis

    Science.gov (United States)

    Ekrami, Yasamin; Cook, Joseph S.

    2011-01-01

    In order to mitigate catastrophic failures on future generation space vehicles, engineers at the National Aeronautics and Space Administration have begun to integrate a novel crew abort systems that could pull a crew module away in case of an emergency at the launch pad or during ascent. The Max Launch Abort System (MLAS) is a recent test vehicle that was designed as an alternative to the baseline Orion Launch Abort System (LAS) to demonstrate the performance of a "tower-less" LAS configuration under abort conditions. The MLAS II test vehicle will execute a propulsive coast stabilization maneuver during abort to control the vehicles trajectory and thrust. To accomplish this, the spacecraft will integrate an Attitude Control System (ACS) with eight hypergolic monomethyl hydrazine liquid propulsion engines that are capable of operating in a quick pulsing mode. Two main elements of the ACS include a propellant distribution subsystem and a pressurization subsystem to regulate the flow of pressurized gas to the propellant tanks and the engines. The CAD assembly of the Attitude Control System (ACS) was configured and integrated into the Launch Abort Vehicle (LAV) design. A dynamic random vibration analysis was conducted on the Main Propulsion System (MPS) helium pressurization panels to assess the response of the panel and its components under increased gravitational acceleration loads during flight. The results indicated that the panels fundamental and natural frequencies were farther from the maximum Acceleration Spectral Density (ASD) vibrations which were in the range of 150-300 Hz. These values will direct how the components will be packaged in the vehicle to reduce the effects high gravitational loads.

  1. Children's oral health-related knowledge, attitudes and beliefs as predictors of success in caries control during a 3.4-year randomized clinical trial.

    Science.gov (United States)

    Hietasalo, Pauliina; Lahti, Satu; Tolvanen, Mimmi; Niinimaa, Ahti; Seppä, Liisa; Hausen, Hannu

    2012-07-01

    The aim of this study was to determine whether the baseline oral health-related knowledge, attitudes and beliefs of the participants in a randomized clinical trial (RCT) were associated with D(3)MFS increment. Additionally, the aim was to study whether the association was mediated by the two baseline behaviors, i.e. brushing teeth and eating candies. Children in Pori, Finland (n = 493) aged 11-12 years, with active initial caries lesion(s) at baseline, were studied. The data were based on clinical examinations in 2001 and 2005 and on a questionnaire administered in 2001. Associations between success in caries control and baseline oral health-related knowledge, attitudes and the belief in keeping one's own teeth throughout life were evaluated using negative binomial regression analyses while considering the effects of the two baseline oral health behaviors. The degree of concern about getting decay in one's own teeth was associated with caries increment. The less concerned the child was about new caries lesions, the more likely he/she was to develop new cavities. This association was not mediated by the two behaviors. Those children who did not know whether or not their mother had cavities were more likely to fail in caries control than were children who knew about their mother's cavities. It is important to determine child's level of concern about getting cavities because children who are concerned about developing cavities are likely to succeed in caries control while the opposite is true for those children who do not share this concern.

  2. Improving primary teachers’ attitudes toward science by attitude-focused professional development

    NARCIS (Netherlands)

    van Aalderen-Smeets, Sandra; Walma van der Molen, Julie Henriëtte

    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

  3. Attitudes towards genetic testing: analysis of contradictions

    DEFF Research Database (Denmark)

    Jallinoja, P; Hakonen, A; Aro, A R

    1998-01-01

    A survey study was conducted among 1169 people to evaluate attitudes towards genetic testing in Finland. Here we present an analysis of the contradictions detected in people's attitudes towards genetic testing. This analysis focuses on the approval of genetic testing as an individual choice...... and on the confidence in control of the process of genetic testing and its implications. Our analysis indicated that some of the respondents have contradictory attitudes towards genetic testing. It is proposed that contradictory attitudes towards genetic testing should be given greater significance both in scientific...... studies on attitudes towards genetic testing as well as in the health care context, e.g. in genetic counselling....

  4. The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1

    Science.gov (United States)

    Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.

    2017-10-01

    This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

  5. The role of beliefs and attitudes about sleep in seasonal and nonseasonal mood disorder, and nondepressed controls.

    Science.gov (United States)

    Roecklein, Kathryn A; Carney, Colleen E; Wong, Patricia M; Steiner, Jessica L; Hasler, Brant P; Franzen, Peter L

    2013-09-05

    Unhelpful sleep-related cognitions play an important role in insomnia and major depressive disorder, but their role in seasonal affective disorder has not yet been explored. Therefore, the purpose of this study was to determine if individuals with seasonal affective disorder (SAD) have sleep-related cognitions similar to those with primary insomnia, and those with insomnia related to comorbid nonseasonal depression. Participants (n=147) completed the Dysfunctional Beliefs and Attitudes about Sleep 16-item scale (DBAS-16) and the Structured Interview Guide for the Hamilton Depression Rating Scale, Seasonal Affective Disorder Version (SIGH-SAD), which assesses self reported sleep problems including early, middle, or late insomnia, and hypersomnia in the previous week. All participants were assessed in winter, and during an episode for those with a depressive disorder. Individuals with SAD were more likely to report hypersomnia on the SIGH-SAD, as well as a combined presentation of hypersomnia and insomnia on the Pittsburgh Sleep Quality Index (PSQI). The SAD group reported DBAS-16 scores in the range associated with clinical sleep disturbance, and DBAS-16 scores were most strongly associated with reports of early insomnia, suggesting circadian misalignment. Limitations include the self-report nature of the SIGH-SAD instrument on which insomnia and hypersomnia reports were based. Future work could employ sleep- or chronobiological-focused interventions to improve clinical response in SAD. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Efficacy of an internet-based learning module and small-group debriefing on trainees' attitudes and communication skills toward patients with substance use disorders: results of a cluster randomized controlled trial.

    Science.gov (United States)

    Lanken, Paul N; Novack, Dennis H; Daetwyler, Christof; Gallop, Robert; Landis, J Richard; Lapin, Jennifer; Subramaniam, Geetha A; Schindler, Barbara A

    2015-03-01

    To examine whether an Internet-based learning module and small-group debriefing can improve medical trainees' attitudes and communication skills toward patients with substance use disorders (SUDs). In 2011-2012, 129 internal and family medicine residents and 370 medical students at two medical schools participated in a cluster randomized controlled trial, which assessed the effect of adding a two-part intervention to the SUDs curricula. The intervention included a self-directed, media-rich Internet-based learning module and a small-group, faculty-led debriefing. Primary study outcomes were changes in self-assessed attitudes in the intervention group (I-group) compared with those in the control group (C-group) (i.e., a difference of differences). For residents, the authors used real-time, Web-based interviews of standardized patients to assess changes in communication skills. Statistical analyses, conducted separately for residents and students, included hierarchical linear modeling, adjusted for site, participant type, cluster, and individual scores at baseline. The authors found no significant differences between the I- and C-groups in attitudes for residents or students at baseline. Compared with those in the C-group, residents, but not students, in the I-group had more positive attitudes toward treatment efficacy and self-efficacy at follow-up (Pcommunication skills toward patients with SUDs among residents. Enhanced attitudes and skills may result in improved care for these patients.

  7. Investigation of Dynamic Aerodynamics and Control of Wind Turbine Sections Under Relevant Inflow/Blade Attitude Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Naughton, Jonathan W. [University of Wyoming

    2014-08-05

    The growth of wind turbines has led to highly variable loading on the blades. Coupled with the relative reduced stiffness of longer blades, the need to control loading on the blades has become important. One method of controlling loads and maximizing energy extraction is local control of the flow on the wind turbine blades. The goal of the present work was to better understand the sources of the unsteady loading and then to control them. This is accomplished through an experimental effort to characterize the unsteadiness and the effect of a Gurney flap on the flow, as well as an analytical effort to develop control approaches. It was planned to combine these two efforts to demonstrate control of a wind tunnel test model, but that final piece still remains to be accomplished.

  8. Attitudes of consumers and live-poultry workers to central slaughtering in controlling H7N9: a cross-sectional study.

    Science.gov (United States)

    Lin, Xiao; Zhang, Dingmei; Wang, Xinwei; Huang, Yun; Du, Zhicheng; Zou, Yaming; Lu, Jiahai; Hao, Yuantao

    2017-05-26

    Guangdong Province in the Pearl River Delta of Southeast China is among the areas in the country with the highest rates of avian flu cases. In order to control the outbreak of human-infected H7N9 cases, Guangdong launched a new policy on the central slaughtering of live poultry in 2015. This study aims to evaluate attitudes of consumers and live-poultry workers toward the policy. The live-poultry workers consisted of two sub-groups: live-poultry traders and poultry farm workers. Consumers and live-poultry workers from Guangdong were enrolled by stratified multi-stage random sampling. Online and field surveys were conducted to investigate participants' attitudes on policy implementation. Questionnaires were developed to quantify participant demographics, to collect information about attitudes toward the policy, and to identify influential factors of policy acceptability. Proportional odds logistics regression was used in the univariate and multivariate analyses. A total of 1449 consumers, 181 live-poultry traders, and 114 poultry farm workers completed the study. Policy acceptability percentages among consumers, live-poultry traders, and poultry farm workers were 57.1, 37.9, and 62.6%, respectively. Logistics regression shows that consumers tended not to support the policy if they were males, if they were concerned with the food safety of chilled products, and if they preferred purchasing live poultry. Live-poultry traders tended not to support if they were subsidized by the government, if they were males, if they experienced a drop in trading volume, and if they were unclear whether avian flu was a preventable disease. Finally, poultry farm workers tended not to support if they experienced a drop in trading volume, if they operated a poultry farm on a small to medium scale, and if they experienced inconvenience in their work due to the policy. The study reveals a substantial refusal or slowness to accept the policy. Failure to accept the policy results from varying

  9. Teaching desertification: An investigation of teacher and classroom attributes, instructional strategies, locus of control, attitudes, and self-efficacy of Namibian junior secondary school teachers

    Science.gov (United States)

    Shimwooshili Shaimemanya, Cornelia Ndahambelela

    The purpose of this study was to investigate the direct and indirect effects of teacher attributes (teaching experience, age, and science content preparation), classroom attributes (grade level, class size, and teaching resources), and instructional strategies on Namibian junior secondary school teachers' locus of control, attitudes toward desertification, and self-efficacy. A multivariate analysis of variance (MANOVA) and path analysis strategy were used to test a hypothesized causal model that expressed the relationships among these factors. Sample data were collected from 221 teachers from 218 schools representing 4 northern education regions of Namibia. Overall MANOVA results were not significant and hence no follow-up analyses were conducted. However, when the causal model was retested in the absence of 13 variables, which were incorrectly specified, MANOVA results, although still not significant, improved considerably: The p-value decreased from 28.5% to 15%. As a result., follow-up analyses were conducted at an inflated alpha level relative to this alternative model. The results indicated that science content preparation, syllabus use, and Internet use had significant influences on teachers' self-efficacy, but none of the IVs had a significant relationship with either of the other two dependent measures. A follow-up exploratory analysis was also conducted using structural equation modeling (SEM) via LISREL. The resulting LISREL model indicated that (1) age and textbook use are positive measures that determine a teacher's ability to teach desertification, (2) Internet use is a negative measure of teachers' desertification teaching ability, and (3) self-efficacy and attitudes toward desertification are measures of teachers' motivation to teach desertification, with self-efficacy as the stronger measure. Findings suggest that: (1) teachers' desertification teaching can be improved by a stronger science content background as part of teacher training programs; (2

  10. The Influence of Science Process Skills, Logical Thinking Abilities, Attitudes towards Science, and Locus of Control on Science Achievement among Form 4 Students in the Interior Division of Sabah, Malaysia

    Science.gov (United States)

    Fah, Lay Yoon

    2008-01-01

    The purpose of this study was to examine the direct and indirect effects of science process skills, logical thinking abilities, attitudes towards science, and locus of control on science achievement among Form 4 students in the Interior Division of Sabah, Malaysia. Research findings showed that there were low to moderate, positive but significant…

  11. The Beliefs, Attitudes and Views of University Students about Anger and the Effects of Cognitive Behavioral Therapy-Oriented Anger Control and Anxiety Management Programs on Their Anger Management Skill Levels

    Science.gov (United States)

    Karahan, T. Fikret; Yalçin, B. Murat; Erbas, Melda M.

    2014-01-01

    This study was designed as a qualitative focus group using a randomized controlled trail with a mixed methodology. The study has dual aims. First we searched the beliefs, attitudes and views of 176 university students on how to deal with anger using eight focus discussion groups. The anxiety and anger levels of these students were investigated…

  12. Knowledge and attitude of key community members towards tuberculosis: Mixed method study from BRAC TB control areas in Bangladesh

    NARCIS (Netherlands)

    Paul, S.; Akter, R.; Aftab, A.; Khan, A.M.; Barua, M.; Islam, S.; Islam, A.; Husain, A.; Sarker, M.

    2015-01-01

    Bangladesh National Tuberculosis (TB) Control Programme adopted a number of strategies to facilitate TB diagnosis and treatment. 'Advocacy, Communication and Social Mobilization' (ACSM) was one of the key strategies implemented by BRAC (Bangladesh Rural Advancement Committee, a non-governmental

  13. Racism, Gun Ownership and Gun Control: Biased Attitudes in US Whites May Influence Policy Decisions: e77552

    National Research Council Canada - National Science Library

    Kerry O'Brien; Walter Forrest; Dermot Lynott; Michael Daly

    2013-01-01

    .... Method The most recent data from the American National Election Study, a large representative US sample, was used to test relationships between racism, gun ownership, and opposition to gun control in US whites...

  14. Knowledge, attitude and practice of hygiene and sanitation in a Burundian refugee camp: implications for control of a Salmonella typhi outbreak.

    Science.gov (United States)

    Nahimana, Marie-Rosette; Ngoc, Candide Tran; Olu, Olushayo; Nyamusore, Jose; Isiaka, Ayodeji; Ndahindwa, Vedaste; Dassanayake, Lakruwan; Rusanganwa, André

    2017-01-01

    A Salmonella typhi outbreak was reported in a Burundian refugee camp in Rwanda in October 2015. Transmission persisted despite increased hygiene promotion activities and hand-washing facilities instituted to prevent and control the outbreak. A knowledge, attitude and practice (KAP) study was carried out to assess the effectiveness of ongoing typhoid fever preventive interventions. A cross-sectional survey was conducted in Mahama Refugee Camp of Kirehe District, Rwanda from January to February 2016. Data were obtained through administration of a structured KAP questionnaire. Descriptive, bivariate and multivariate analysis was performed using STATA software. A total of 671 respondents comprising 264 (39.3%) males and 407 (60.7%) females were enrolled in the study. A comparison of hand washing practices before and after institution of prevention and control measures showed a 37% increase in the proportion of respondents who washed their hands before eating and after using the toilet (p practices. The findings of this study underline the need for bolstering up health education and hygiene promotion activities in Mahama and other refugee camp settings.

  15. Exploring Attitudes and Beliefs towards Implementing Cattle Disease Prevention and Control Measures: A Qualitative Study with Dairy Farmers in Great Britain

    Directory of Open Access Journals (Sweden)

    Marnie L. Brennan

    2016-10-01

    Full Text Available Disease prevention and control practices are frequently highlighted as important to ensure the health and welfare of farmed animals, although little is known as to why not many practices are carried out. The aim of this study was to identify the motivators and barriers of dairy cattle farmers towards the use of biosecurity measures on dairy farms using a health psychology approach. Twenty-five farmers on 24 farms in Great Britain (GB were interviewed using the Theory of Planned Behaviour framework. Results indicated that farmers perceived they had the ability to control what happened on their farms in terms of preventing and controlling disease, and described benefits from being proactive and vigilant. However, barriers were cited in relation to testing inaccuracies, effectiveness and time-efficiency of practices, and disease transmission route (e.g., airborne transmission. Farmers reported they were positively influenced by veterinarians and negatively influenced by the government (Department for Environment Food & Rural Affairs (DEFRA and the general public. Decisions to implement practices were influenced by the perceived severity of the disease in question, if disease was diagnosed on the farm already, or was occurring on other farms. Farmers described undertaking a form of personal risk assessment when deciding if practices were worth doing, which did not always involve building in disease specific factors or opinions from veterinarians or other advisors. These results indicate that further guidance about the intricacies of control and prevention principles in relation to specific animal diseases may be required, with an obvious role for veterinarians. There appears to be an opportunity for farm advisors and herd health professionals to further understand farmer beliefs behind certain attitudes and target communication and advice accordingly to further enhance dairy cattle health and welfare.

  16. New Zealand tobacco retailers' attitudes to selling tobacco, point-of-sale display bans and other tobacco control measures: a qualitative analysis.

    Science.gov (United States)

    Jaine, Richard; Russell, Marie; Edwards, Richard; Thomson, George

    2014-06-20

    We aimed to explore New Zealand tobacco retailers' views on selling tobacco, the forthcoming 2012 point of sale display ban and two other potential tobacco control interventions in the retail setting: compulsory sales of nicotine replacement therapy and licensing of tobacco retailers. We carried out in-depth interviews with 18 retailers from a variety of store types where tobacco was sold. Stores were selected from a range of locations with varying levels of deprivation. We used thematic analysis to analyse the data. All but four of the retailers were ambivalent about selling tobacco, would rather not sell it, or fell back on a business imperative for justification. Only one retailer was explicitly unconcerned about selling tobacco products. Most participants had few or no concerns about the removal of point-of-sale displays. Issues which were raised were mainly practical and logistical issues with the removal of displays. Only three thought sales would definitely be reduced. The majority of the retailers were not opposed to a possible requirement that nicotine replacement therapy products be made available wherever tobacco products are sold. Ten supported a licensing or registration scheme for tobacco retailers, and only three were opposed. We found widespread ambivalence about selling tobacco. There was considerable support for the licensing of tobacco retailers and other potential tobacco control measures. The retailers' attitudes about potential financial costs and security issues from a tobacco display ban were at odds with the tobacco industry predictions and the views of retailers' organisations. Some retailers appear to be potential allies for tobacco control. This is in contrast to retailer organisations, which may be out of step with many of their members in their strong opposition to retail tobacco control interventions.

  17. Credit Card Misuse, Money Attitudes, and Compulsive Buying Behaviors: A Comparison of Internal and External Locus of Control (LOC) Consumers

    Science.gov (United States)

    Watson, Stevie

    2009-01-01

    This study examined attitudinal and behavioral differences between internal and external locus of control (LOC) consumers on credit card misuse, the importance of money, and compulsive buying. Using multiple analysis of variance and separate analyses of variance, internal LOC consumers were found to have lower scores on credit card misuse and…

  18. Project SUCCESS' Effects on Substance Use-Related Attitudes and Behaviors: A Randomized Controlled Trial in Alternative High Schools

    Science.gov (United States)

    Clark, Heddy Kovach; Ringwalt, Chris L.; Shamblen, Stephen R.; Hanley, Sean M.

    2011-01-01

    Using a randomized controlled effectiveness trial, we examined the effects of Project SUCCESS on a range of secondary outcomes, including the program's mediating variables. Project SUCCESS, which is based both on the Theory of Reasoned Action and on Cognitive Behavior Theory, is a school-based substance use prevention program that targets…

  19. GO JUPTER POS ANCILLARY ROTOR ATTITUDE V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the attitude data for the rotor of the Galileo spacecraft. The data provided are derived from the Attitude and Articulation Control System...

  20. The Diabetes Intention, Attitude, and Behavior Questionnaire: evaluation of a brief questionnaire to measure physical activity, dietary control, maintenance of a healthy weight, and psychological antecedents.

    Science.gov (United States)

    Traina, Shana B; Mathias, Susan D; Colwell, Hilary H; Crosby, Ross D; Abraham, Charles

    2016-01-01

    This study assessed measurement properties of the 17-item Diabetes Intention, Attitude, and Behavior Questionnaire (DIAB-Q), which measures intention to engage in self-care behaviors, including following a diabetes diet and engaging in appropriate physical activity. The DIAB-Q includes questions based on the Theory of Planned Behavior. Items were developed using published literature, input from health care professionals, and qualitative research findings in patients with and without type 2 diabetes mellitus (T2DM). In Stage I of the study, 23 adults with T2DM were interviewed to evaluate the content and clarity of the DIAB-Q. In Stage II 1,015 individuals with T2DM completed the DIAB-Q and supplemental questionnaires, including the Short Form-36 acute (SF-36), section III of the Multidimensional Diabetes Questionnaire, the Summary of Diabetes Self-Care Activities questionnaire, and self-administered items relevant to the treatment and management of T2DM (eg, blood pressure and glycated hemoglobin [HbA1c]) at baseline and 3-7 days later. Once the DIAB-Q scale structure was determined, its test-retest reliability, construct validity, and known-groups validity were evaluated, and minimal clinically important change was estimated. In Stage I, the 23 respondents surveyed generally reported that the DIAB-Q was clear and comprehensive and endorsed questions as relevant to their intentions to engage in diabetes-related self-care activities. Most subjects in Stage II were male, Caucasian, and married. Mean age was 63 years. Factor analysis revealed six psychological constructs (Behavior, Planning, Intention, Perceived Behavioral Control, Attitude, and Subjective Norm). Test-retest reliability was acceptable (≥0.70) for all scales, except Perceived Behavioral Control. Construct validity was demonstrated based on correlations with diabetes-specific items/scales and the SF-36. Known-groups validity was confirmed for Behavior, Planning, and Intention when respondents were

  1. The Diabetes Intention, Attitude, and Behavior Questionnaire: evaluation of a brief questionnaire to measure physical activity, dietary control, maintenance of a healthy weight, and psychological antecedents

    Directory of Open Access Journals (Sweden)

    Traina SB

    2016-02-01

    -related self-care activities. Most subjects in Stage II were male, Caucasian, and married. Mean age was 63 years. Factor analysis revealed six psychological constructs (Behavior, Planning, Intention, Perceived Behavioral Control, Attitude, and Subjective Norm. Test–retest reliability was acceptable (≥0.70 for all scales, except Perceived Behavioral Control. Construct validity was demonstrated based on correlations with diabetes-specific items/scales and the SF-36. Known-groups validity was confirmed for Behavior, Planning, and Intention when respondents were categorized into groups that differed based on body mass index, disease severity, and HbA1c. Item scores were transformed to a 100-point scale, and minimal clinically important change estimates ranged from 6–11 points, representing the change that would be considered important to a respondent. Conclusion: The DIAB-Q is a brief, psychometrically sound, patient-reported outcome that can be used among individuals with T2DM to evaluate intention to engage in self-care behaviors. Keywords: diabetes, Theory of Planned Behavior, DIAB-Q, attitude, intention, behavior, patient-reported outcome, questionnaire

  2. Attitude Determination and Control System Design for a 6U Cube Sat for Proximity Operations and Rendezvous

    Science.gov (United States)

    2014-08-04

    USA Michael V. Nayak § Red Sky Research, Albuquerque, New Mexico , 87108, USA Thorsten Pueschl ¶ dSPACE GmbH, Paderborn, 32102, Germany The work...volume, mass, and power constraints led to the decision of eliminating the reaction wheels in favor of an RCS thruster actuated control system. A trade ...the same distur- bance scenario was presented to the thruster actuated system. The total propellant per orbit needed to reject all exterior

  3. Willingness-to-pay for Crime Control Programs in Norway: Preferences and Attitudes towards Crime and Crime Reduction.

    OpenAIRE

    Antonsen, Sicilia Heien; Wiig, Emilie Kristine

    2017-01-01

    Master's thesis in Economic analysis In this pilot study, we use the contingent valuation (CV) method to investigate Norwegians willingness to pay (WTP) for crime control programs. The CV method is well known in the environmental economics literature, and has later also been used to estimate the intangible costs of crime. There is a lack of knowledge about the costs of crime in Norway, and especially about the intangible costs which can be argued to constitute the biggest part of the costs...

  4. [Beauticians' eating attitudes and body attitudes].

    Science.gov (United States)

    Lukács-Márton, Réka; Szabó, Pál

    2013-01-01

    Some professional groups (models, actresses, ballet dancers, jockeys and athletes) are considered as risk populations for eating disorders and body image disorders. Beauticians may be a possible risk group, as their work is closely related to beauty and fashion. Eating disorders were assessed using the Eating Attitudes Test and the Eating Behaviour Severity Scale, body image measures included the Human Figure Drawings Test, the Body Dissatisfaction Subscale of the Eating Disorders Inventory, the Body Attitudes Test, and the Body Investment Scale. Questionnaire data of 276 subjects were analysed. The study sample comprised 128 beauticians from Transylvania (5 males, 123 females). This group was compared with a control group consisting of 148 subjects (25 males, 123 females). Such weight reducing methods as dieting, exercise, the use of appetite suppressants and diuretics were significantly more prevalent in the beautician group. Mean total score and the scores of the Dieting subscale of the Eating Disorders Inventory were significantly (p eating disorders (2.4% subclinical bulimia nervosa and 1.6% subclinical anorexia nervosa) was significantly higher in the beautician group. Beauticians invest significantly (p body care. The above results suggest that working in the beauty industry may represent an increased risk of developing eating disorders.

  5. Willingness-to-pay for Crime Control Programs in Norway: Preferences and Attitudes towards Crime and Crime Reduction.

    OpenAIRE

    Antonsen, Sicilia Heien; Wiig, Emilie Kristine

    2017-01-01

    In this pilot study, we use the contingent valuation (CV) method to investigate Norwegians willingness to pay (WTP) for crime control programs. The CV method is well known in the environmental economics literature, and has later also been used to estimate the intangible costs of crime. There is a lack of knowledge about the costs of crime in Norway, and especially about the intangible costs which can be argued to constitute the biggest part of the costs and be the most damaging for the victim...

  6. Towards an effective control programme of soil-transmitted helminth infections among Orang Asli in rural Malaysia. Part 2: Knowledge, attitude, and practices.

    Science.gov (United States)

    Nasr, Nabil A; Al-Mekhlafi, Hesham M; Ahmed, Abdulhamid; Roslan, Muhammad Aidil; Bulgiba, Awang

    2013-01-28

    In the first part of this study, we investigated the prevalence and associated key factors of soil-transmitted helminth (STH) infections among Orang Asli children in rural Malaysia; an alarming high prevalence and five key factors significantly associated with infections were reported. Part 2 of this study aims to evaluate the knowledge, attitude and practices (KAP) on STH infections among Orang Asli in Peninsular Malaysia. A cross-sectional study was carried out among 215 households from 13 villages in Lipis district, Pahang, Malaysia. Demographic and socioeconomic information of the participants and their KAP on STH were collected by using a pre-tested questionnaire. Overall, 61.4% of the participants had prior knowledge about intestinal helminths with a lack of knowledge on the transmission (28.8%), signs and symptoms (29.3%) as well as the prevention (16.3%). Half of the respondents considered STH as harmful, while their practices to prevent infections were still inadequate. Significant associations between the KAP and age, gender, educational and employment status, family size, and household monthly income were reported. Moreover, significantly lower prevalence of STH infections was reported among children of respondents who wear shoes/slippers when outside the house (72.8%; 95% CI= 62.6, 80.5 vs 87.0%; 95% CI= 81.4, 91.1), wash their hands before eating (32.4%; 95% CI= 24.3, 42.2 vs 51.4%; 95% CI= 44.7, 60.1), and wash their hands after defecation (47.8%; 95% CI= 35.7, 57.1 vs 69.2%; 95% CI= 63.7, 78.7) as compared to their counterparts. Multiple logistic regression analysis indicated that the educational level of the respondents was the most important factor significantly associated with the KAP on STH among this population. This study reveals inadequate knowledge, attitude and practices on STH infections among Orang Asli in rural Malaysia. Hence, there is a great need for a proper health education programme and community mobilisation to enhance prevention

  7. Towards an effective control programme of soil-transmitted helminth infections among Orang Asli in rural Malaysia. Part 2: Knowledge, attitude, and practices

    Directory of Open Access Journals (Sweden)

    Nasr Nabil A

    2013-01-01

    Full Text Available Abstract Background In the first part of this study, we investigated the prevalence and associated key factors of soil-transmitted helminth (STH infections among Orang Asli children in rural Malaysia; an alarming high prevalence and five key factors significantly associated with infections were reported. Part 2 of this study aims to evaluate the knowledge, attitude and practices (KAP on STH infections among Orang Asli in Peninsular Malaysia. Methods A cross-sectional study was carried out among 215 households from 13 villages in Lipis district, Pahang, Malaysia. Demographic and socioeconomic information of the participants and their KAP on STH were collected by using a pre-tested questionnaire. Results Overall, 61.4% of the participants had prior knowledge about intestinal helminths with a lack of knowledge on the transmission (28.8%, signs and symptoms (29.3% as well as the prevention (16.3%. Half of the respondents considered STH as harmful, while their practices to prevent infections were still inadequate. Significant associations between the KAP and age, gender, educational and employment status, family size, and household monthly income were reported. Moreover, significantly lower prevalence of STH infections was reported among children of respondents who wear shoes/slippers when outside the house (72.8%; 95% CI= 62.6, 80.5 vs 87.0%; 95% CI= 81.4, 91.1, wash their hands before eating (32.4%; 95% CI= 24.3, 42.2 vs 51.4%; 95% CI= 44.7, 60.1, and wash their hands after defecation (47.8%; 95% CI= 35.7, 57.1 vs 69.2%; 95% CI= 63.7, 78.7 as compared to their counterparts. Multiple logistic regression analysis indicated that the educational level of the respondents was the most important factor significantly associated with the KAP on STH among this population. Conclusion This study reveals inadequate knowledge, attitude and practices on STH infections among Orang Asli in rural Malaysia. Hence, there is a great need for a proper health education

  8. Weight self-regulation process in adolescence: the relationship between control weight attitudes, behaviors and body weight status

    Directory of Open Access Journals (Sweden)

    Jordi ePich

    2015-05-01

    Full Text Available Adolescents’ self-control weight behaviors were assessed (n= 1961; 12-17 years old; 2007-2008 in the Balearic Islands, Spain. The study analyzed the relationships between body weight status, body image and self-weight concern, and actual attempts to lose weight by restrained eating and/or increased exercising. In terms of regulatory focus theory (RFT, we considered that efforts to lose or to maintain weight (successful or failed would be motivated either by a promotion focus (to show an attractive body, a prevention focus (to avoid social rejection of fatness, or both. Results showed that 41% of overweight boys and 25% of obese boys stated that they had never made any attempt to lose weight, and 13% and 4% in females. Around half of overweight boys and around a quarter of obese boys stated that they were Not at all concerned about weight gain, and girls’ percentages decreased to 13% and 11% respectively. By contrast 57% of normal weight girls monitored their weight and stated that they had tried to slim at least once. Weight self-regulation in females attempted to combine diet and exercise, while boys relied almost exclusively on exercise. Apparent lack of consciousness of body weight status among overweight boys, and more important, subsequent absence of behaviors to reduce their weight clearly challenges efforts to prevent obesity. We argue that several causes may be involved in this outcome, including unconscious emotional (self-defense and cognitive (dissonance mechanisms driven by perceived social stigmatization of obesity. The active participation of social values of male and female body image (strong vs. pretty and the existence of social habituation to overweight are suggested. A better knowledge of psychosocial mechanisms underlying adolescent weight self-control may improve obesity epidemics.

  9. The HOT (Healthy Outcome for Teens) project. Using a web-based medium to influence attitude, subjective norm, perceived behavioral control and intention for obesity and type 2 diabetes prevention.

    Science.gov (United States)

    Muzaffar, Henna; Chapman-Novakofski, Karen; Castelli, Darla M; Scherer, Jane A

    2014-01-01

    We hypothesized that Theory of Planned Behavior (TPB) constructs (behavioral belief, attitude, subjective norm, perceived behavioral control, knowledge and behavioral intention) regarding preventive behaviors for obesity and type 2 diabetes will change favorably after completing the web-based intervention, HOT (Healthy Outcome for Teens) project, grounded in the TPB; and that passive online learning (POL) group will improve more than the active online learning (AOL) group. The secondary hypothesis was to determine to what extent constructs of the TPB predict intentions. 216 adolescents were recruited, 127 randomly allocated to the treatment group (AOL) and 89 to the control group (POL). The subjects completed a TPB questionnaire pre and post intervention. Both POL and AOL groups showed significant improvements from pretest to posttest survey. However, the results indicated no significant difference between POL and AOL for all constructs except behavioral belief. Correlational analysis indicated that all TPB constructs were significantly correlated with intentions for pretest and posttest for both groups. Attitude and behavioral control showed strongest correlations. Regression analysis indicated that TPB constructs were predictive of intentions and the predictive power improved post intervention. Behavioral control consistently predicted intentions for all categories and was the strongest predictor for pretest scores. For posttest scores, knowledge and attitude were the strongest predictors for POL and AOL groups respectively. Thus, HOT project improved knowledge and the TPB constructs scores for targeted behaviors, healthy eating and physical activity, for prevention of obesity and type 2 diabetes. Published by Elsevier Ltd.

  10. Farmers' Attitudes and Behavior toward Sustainable Agriculture.

    Science.gov (United States)

    Petrzelka, Peggy; Korsching, Peter F.; Malia, James E.

    1996-01-01

    A mail survey of Iowa farmers with membership in Practical Farmers of Iowa (PFI), a sustainable agriculture organization, was used to examine the attitude-behavior relationship of these farmers and the role social influences played in this relationship. Results indicate that when controlling explanatory factors, the attitude-behavior relationship…

  11. Attitudes Towards Dreams, Sex Differences and Creativity.

    Science.gov (United States)

    Domino, George

    1982-01-01

    A questionnaire about dreams (QAD) was administered to 196 high school students to develop an "attitudes toward dreams" questionnaire and to explore the relationship of such attitudes to creativity. The QAD was also administered to 23 high school students who showed evidence of creative achievement and 23 control Ss. (SW)

  12. Knowledge, attitude, reported behaviour and perceived challenges ...

    African Journals Online (AJOL)

    Aim: The aim of this study was to investigate the knowledge, attitude, reported behavior and the perceived barriers to routine use of infection control measures in dental practice among dental practitioners working in government dental clinics in Tanzania mainland. Methods: A 56 items questionnaire on knowledge, attitude, ...

  13. Evaluation of an Online Campaign for Promoting Help-Seeking Attitudes for Depression Using a Facebook Advertisement: An Online Randomized Controlled Experiment

    OpenAIRE

    Hui, Alison; Wong, Paul Wai-Ching; Fu, King-wa

    2015-01-01

    Background A depression-awareness campaign delivered through the Internet has been recommended as a public health approach that would enhance mental health literacy and encourage help-seeking attitudes. However, the outcomes of such a campaign remain understudied. Objective The main aim of this study was to evaluate the effectiveness of an online depression awareness campaign, which was informed by the theory of planned behavior, to encourage help-seeking attitudes for depression and to enhan...

  14. Attitudes toward emotions.

    Science.gov (United States)

    Harmon-Jones, Eddie; Harmon-Jones, Cindy; Amodio, David M; Gable, Philip A

    2011-12-01

    The present work outlines a theory of attitudes toward emotions, provides a measure of attitudes toward emotions, and then tests several predictions concerning relationships between attitudes toward specific emotions and emotional situation selection, emotional traits, emotional reactivity, and emotion regulation. The present conceptualization of individual differences in attitudes toward emotions focuses on specific emotions and presents data indicating that 5 emotions (anger, sadness, joy, fear, and disgust) load on 5 separate attitude factors (Study 1). Attitudes toward emotions predicted emotional situation selection (Study 2). Moreover, attitudes toward approach emotions (e.g., anger, joy) correlated directly with the associated trait emotions, whereas attitudes toward withdrawal emotions (fear, disgust) correlated inversely with associated trait emotions (Study 3). Similar results occurred when attitudes toward emotions were used to predict state emotional reactivity (Study 4). Finally, attitudes toward emotions predicted specific forms of emotion regulation (Study 5).

  15. A Randomized Controlled Study on the Effects of a Documentary on Students’ Empathy and Attitudes towards Older Adults

    Science.gov (United States)

    Laganá, Luciana; Gavrilova, Larisa; Carter, Delwin B.; Ainsworth, Andrew T.

    2017-01-01

    Background Despite the rapid increase in the size of the geriatric population, no current published literature is available based on the effects of viewing a documentary covering medical and psychosocial issues concerning older adults influencing young people’s empathy and ageism. The aim of the current study was to test whether participants who viewed an original documentary about older adults experiencing physical pain would report lower ageism and higher empathy scores when compared to participants who watched a neutral documentary. Method Seventy-seven students (ages 18–29 years) were randomized to either the experimental (pain documentary) or the control (neutral documentary) conditions and given pre- and post-test measures of empathy and ageism. Results The results of a series of Profile Analyses (Multivariate Mixed ANOVAs) showed a significant interaction (Wilk’s λ=0.933, F(1,75)=5.389, p=0.023, partial η2=0.067) between treatment and time (pre- vs. post-viewing the film) for the empathy measure that was confirmed by follow-up t-tests. The latter showed a significant increase in empathy scores for only the experimental group, t(37)=−2.999, p=0.005. However, contrary to the original prediction, this same treatment by time effect was not observed for ageism (Wilk’s λ=0.994, F(1,75)=0.482, p=0.490, partial η2=0.006), as the experimental participants did not significantly reduce their ageism scores, t(38)=0.725, p=0.473. The results of these analyses, as well as those obtained by using the subscales of each questionnaire, have been discussed. Conclusions The findings of this preliminary study indicate that showing a pain-based, anti-bias documentary feature film has the potential to significantly improve empathy towards older adults in university students. PMID:29399638

  16. Predictive Attitude Maintenance For A Space Station

    Science.gov (United States)

    Hattis, Philip D.

    1989-01-01

    Paper provides mathematical basis for predictive management of angular momenta of control-moment gyroscopes (CMG's) to control attitude of orbiting space station. Numerical results presented for pitch control of proposed power-tower space station. Based on prior orbit history and mathematical model of density of atmosphere, predictions made of requirements on dumping and storage of angular momentum in relation to current loading state of CMG's and to acceptable attitude tolerances.

  17. Explicit- and Implicit Bullying Attitudes in Relation to Bullying Behavior

    Science.gov (United States)

    van Goethem, Anne A. J.; Scholte, Ron H. J.; Wiers, Reinout W.

    2010-01-01

    The main aim of this study was to examine whether an assessment of implicit bullying attitudes could add to the prediction of bullying behavior after controlling for explicit bullying attitudes. Primary school children (112 boys and 125 girls, M age = 11 years, 5 months) completed two newly developed measures of implicit bullying attitudes (a…

  18. Development and psychometric testing of the Attitudes, Subjective Norms, Perceived Behavioural Control, and Intention to Pursue a Career in Mental Health Nursing scale.

    Science.gov (United States)

    Wilbourn, Mark; Salamonson, Yenna; Ramjan, Lucie; Chang, Sungwon

    2017-01-19

    The aim of the present study was to develop and test the psychometric properties of the Attitudes, Subjective Norms, Perceived Behavioural Control, and Intention to Pursue a Career in Mental Health Nursing (ASPIRE) scale, an instrument to assess nursing students' intention to work in mental health nursing. Understanding the factors influencing undergraduate nursing students' career intentions might lead to improved recruitment strategies. However, there are no standardized tools to measure and assess students' intention to pursue a career in mental health nursing. The present study used a cross-sectional survey design undertaken at a large tertiary institution in Western Sydney (Australia) between May and August 2013. It comprised three distinct and sequential phases: (i) items were generated representing the four dimensions of the theory of planned behaviour; (ii) face and content validity were tested by a representative reference group and panel of experts; and (iii) survey data from 1109 first- and second-year and 619 third-year students were used in exploratory and confirmatory factor analyses to test the factorial validity of the scale. Internal consistency was measured using Cronbach's alpha. Items generated for the ASPIRE scale were subject to face and content validity testing. Results showed good factorial validity and reliability for the final 14-item scale. Principal axis factoring revealed a one-factor solution, the hypothesized model being supported by confirmatory factor analysis. The ASPIRE scale is a valid and reliable instrument for measuring intention to pursue a career in mental health nursing among Bachelor of Nursing students. © 2017 Australian College of Mental Health Nurses Inc.

  19. Patients' knowledge, attitudes, behaviour and health care experiences on the prevention, detection, management and control of hypertension in Colombia: a qualitative study.

    Directory of Open Access Journals (Sweden)

    Helena Legido-Quigley

    Full Text Available Hypertension is a leading cause of premature death worldwide and the most important modifiable risk factor for cardiovascular disease. Effective screening programs, communication with patients, regular monitoring, and adherence to treatment are essential to successful management but may be challenging in health systems facing resource constraints. This qualitative study explored patients' knowledge, attitudes, behaviour and health care seeking experiences in relation to detection, treatment and control of hypertension in Colombia. We conducted in-depth interviews and focus group discussions with 26 individuals with hypertension and 4 family members in two regions. Few participants were aware of ways to prevent high blood pressure. Once diagnosed, most reported taking medication but had little information about their condition and had a poor understanding of their treatment regime. The desire for good communication and a trusting relationship with the doctor emerged as key themes in promoting adherence to medication and regular attendance at medical appointments. Barriers to accessing treatment included co-payments for medication; costs of transport to health care facilities; unavailability of drugs; and poor access to specialist care. Some patients overcame these barriers with support from social networks, family members and neighbours. However, those who lacked such support, experienced loneliness and struggled to access health care services. The health insurance scheme was frequently described as administratively confusing and those accessing the state subsidized system believed that the treatment was inferior to that provided under the compulsory contributory system. Measures that should be addressed to improve hypertension management in Colombia include better communication between health care professionals and patients, measures to improve understanding of the importance of adherence to treatment, reduction of co-payments and transport

  20. Patients' knowledge, attitudes, behaviour and health care experiences on the prevention, detection, management and control of hypertension in Colombia: a qualitative study.

    Science.gov (United States)

    Legido-Quigley, Helena; Camacho Lopez, Paul Anthony; Balabanova, Dina; Perel, Pablo; Lopez-Jaramillo, Patricio; Nieuwlaat, Robby; Schwalm, J-D; McCready, Tara; Yusuf, Salim; McKee, Martin

    2015-01-01

    Hypertension is a leading cause of premature death worldwide and the most important modifiable risk factor for cardiovascular disease. Effective screening programs, communication with patients, regular monitoring, and adherence to treatment are essential to successful management but may be challenging in health systems facing resource constraints. This qualitative study explored patients' knowledge, attitudes, behaviour and health care seeking experiences in relation to detection, treatment and control of hypertension in Colombia. We conducted in-depth interviews and focus group discussions with 26 individuals with hypertension and 4 family members in two regions. Few participants were aware of ways to prevent high blood pressure. Once diagnosed, most reported taking medication but had little information about their condition and had a poor understanding of their treatment regime. The desire for good communication and a trusting relationship with the doctor emerged as key themes in promoting adherence to medication and regular attendance at medical appointments. Barriers to accessing treatment included co-payments for medication; costs of transport to health care facilities; unavailability of drugs; and poor access to specialist care. Some patients overcame these barriers with support from social networks, family members and neighbours. However, those who lacked such support, experienced loneliness and struggled to access health care services. The health insurance scheme was frequently described as administratively confusing and those accessing the state subsidized system believed that the treatment was inferior to that provided under the compulsory contributory system. Measures that should be addressed to improve hypertension management in Colombia include better communication between health care professionals and patients, measures to improve understanding of the importance of adherence to treatment, reduction of co-payments and transport costs, and easier access

  1. Pengetahuan, Sikap, dan Praktik Pemilik Breeding Kennel terhadap Pencegahan dan Pengendalian Bruselosis pada Anjing Impor (KNOWLEDGE, ATTITUDE, AND PRACTISES OF BREEDING KENNEL OWNER REGARDING CANINE BRUCELLOSIS PREVENTION AND CONTROLLING ON IMPORTED DOGS

    Directory of Open Access Journals (Sweden)

    Citra Noviana

    2016-07-01

    Full Text Available This study was conducted to determine the seroprevalence of Brucella canis of imported dog for breederthrough Soekarno Hatta International Airport, Cengkareng Tanggerang, Indonesia. A total of 64 serumsamples were obtained from breeder dogs imported to Indonesia between Mei–September 2014. Theserums were examined by Immunochromatographic Assay. None of the serum samples in this studytested positive. Result of this study indicated that antibodies of B. canis were not detected in 64 dogsimported to Indonesia during the research period. A Knowledge, Attitude and Practises (KAP Survey wasalso performed. This study used 32 respondents and data were analyzed by using path analysis. Therespondents were breeding kennel owners (breeder who imported dogs through Soekarno HattaInternational Airport during the research period. The study concluded that the knowledge significantlyinfluenced the attitude of the breeder, and also the attitude significantly influenced the practises ofpreventing and controlling brucellosis. The annually income was also identified as a variable thatsignificantly influenced the practises. Practice prevention and control of canine brucellosis can be improvedby increasing the knowledge of the breeding kennel owner.

  2. A psychosocial analysis of parents' decisions for limiting their young child's screen time: An examination of attitudes, social norms and roles, and control perceptions.

    Science.gov (United States)

    Hamilton, Kyra; Spinks, Teagan; White, Katherine M; Kavanagh, David J; Walsh, Anne M

    2016-05-01

    Preschool-aged children spend substantial amounts of time engaged in screen-based activities. As parents have considerable control over their child's health behaviours during the younger years, it is important to understand those influences that guide parents' decisions about their child's screen time behaviours. A prospective design with two waves of data collection, 1 week apart, was adopted. Parents (n = 207) completed a Theory of Planned Behaviour (TPB)-based questionnaire, with the addition of parental role construction (i.e., parents' expectations and beliefs of responsibility for their child's behaviour) and past behaviour. A number of underlying beliefs identified in a prior pilot study were also assessed. The model explained 77% (with past behaviour accounting for 5%) of the variance in intention and 50% (with past behaviour accounting for 3%) of the variance in parental decisions to limit child screen time. Attitude, subjective norms, perceived behavioural control, parental role construction, and past behaviour predicted intentions, and intentions and past behaviour predicted follow-up behaviour. Underlying screen time beliefs (e.g., increased parental distress, pressure from friends, inconvenience) were also identified as guiding parents' decisions. Results support the TPB and highlight the importance of beliefs for understanding parental decisions for children's screen time behaviours, as well as the addition of parental role construction. This formative research provides necessary depth of understanding of sedentary lifestyle behaviours in young children which can be adopted in future interventions to test the efficacy of the TPB mechanisms in changing parental behaviour for their child's health. What is already known on this subject? Identifying determinants of child screen time behaviour is vital to the health of young people. Social-cognitive and parental role constructions are key influences of parental decision-making. Little is known about the

  3. Rationale, design and methods for a staggered-entry, waitlist controlled clinical trial of the impact of a community-based, family-centred, multidisciplinary program focussed on activity, food and attitude habits (Curtin University’s Activity, Food and Attitudes Program—CAFAP among overweight adolescents

    Directory of Open Access Journals (Sweden)

    Straker Leon M

    2012-06-01

    Full Text Available Abstract Background Current estimates place just under one quarter of adolescents in Australia as overweight or obese. Adolescence has been identified as a critical period for the development of obesity, yet despite this recognition, there is limited systematic research into or evaluation of interventions for overweight adolescents. Reviews have concluded that there is a substantive evidence gap for effective intervention, but physical activity, lifestyle change and family involvement have been identified as promising foci for treatment. Methods This paper reports on the development of a staggered-entry, waitlist controlled clinical trial to assess the impact of a multidisciplinary intervention aiming to change the poor health trajectory of overweight adolescents and help them avoid morbid obesity in adulthood—Curtin University’s Activity, Food and Attitudes Program (CAFAP. 96 adolescents, aged 11–16 years, and parents, will attend twice weekly during an 8 week intensive multidisciplinary program with maintenance follow-up focussed on improving activity, food and attitude habits. Follow-up assessments will be conducted immediately after completing the intensive program, and at 3, 6 and 12 months post intensive program. Main outcomes will be objectively-measured physical activity, sedentary behaviour and activity behaviours; food intake (measured by 3 day diary and food behaviours; body composition, fitness and physical function; mental and social well-being (quality of life, mood and attitudes, and family functioning. Discussion This trial will provide important information to understand whether a community based multidisciplinary intervention can have short and medium term effects on activity and food habits, attitudes, and physical and mental health status of overweight adolescents. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12611001187932.

  4. Instructional strategies to improve women's attitudes toward science

    Science.gov (United States)

    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

  5. Developing and testing attitude scales around IT.

    Science.gov (United States)

    Ward, Rod; Glogowska, Margaret; Pollard, Katherine; Moule, Pam

    2009-01-01

    Information technology (IT) is an integral component of the healthcare delivery arsenal. However, not all professionals are happy or comfortable with such technology. To assess professionals' attitudes to IT-use in the workplace, a new questionnaire, the Information Technology Attitude Scales for Health (ITASH). which comprises three scales that can be used to measure the attitudes of UK health professionals, has been developed. Here, the authors describe existing scales, why a new scale was required, and how analysing data from a questionnaire using exploratory factor analysis determined the components of the three scales: efficiency of care; education, training and development; and control.

  6. A Raspberry Pi-Based Attitude Sensor

    Science.gov (United States)

    Sreejith, A. G.; Mathew, Joice; Sarpotdar, Mayuresh; Mohan, Rekhesh; Nayak, Akshata; Safonova, Margarita; Murthy, Jayant

    We have developed a lightweight low-cost attitude sensor, based on a Raspberry Pi, built with readily available commercial components. It can be used in experiments where weight and power are constrained, such as in high-altitude lightweight balloon flights. This attitude sensor will be used as a major building block in a closed-loop control system with driver motors to stabilize and point cameras and telescopes for astronomical observations from a balloon-borne payload.

  7. Male Knowledge, Attitudes, and Family

    African Journals Online (AJOL)

    ces enquêtés là qui n'emploient pas les contraceptifs, les attitudes des hommes sont surtout importantes pour la prise des décisions à l'égard de ... Giventhe decision- making powers of Hausa men and the fact that they also control economic resources, it is important to consider their attitudestoward and willingness touse ...

  8. Effects of the First Line Diabetes Care (FiLDCare) self-management education and support project on knowledge, attitudes, perceptions, self-management practices and glycaemic control: a quasi-experimental study conducted in the Northern Philippines.

    Science.gov (United States)

    Ku, Grace Marie V; Kegels, Guy

    2014-08-11

    To investigate the effects of implementing a context-adapted diabetes self-management education and support (DSME/S) project based on chronic care models in the Philippines, on knowledge, attitudes, self-management practices, adiposity/obesity and glycaemia of people with diabetes. Prospective quasi-experimental before-after study. 203 people with type 2 diabetes mellitus from two local government units in the Northern Philippines fulfilling set criteria. Context-adapted DSME/S was given to a cohort of people with diabetes by trained pre-existing local government healthcare personnel. Changes in knowledge, attitudes and self-management practices, body mass index, waist circumference, waist-hip ratio (WHR) and glycosylated haemoglobin (HbA1c) were measured 1 year after full project implementation. Non-parametric and parametric descriptive and inferential statistics including logistic regression analysis were done. Complete data were collected from 164 participants. Improvements in glycaemia, waist circumference, WHR, knowledge, some attitudes, adherence to medications and exercise, and an increase in fear of diabetes were significant. Reductions in HbA1c, regardless of level of control, were noted in 60.4%. Significant increase in knowledge (pattitude (p=0.013), perceived ability to control blood glucose (p=0.004) and adherence to medications (p=0.001) were noted among those whose glycaemia improved. Significant differences between the subgroups whose HbA1c improved and those whose HbA1c deteriorated include male gender (p=0.042), shorter duration of diabetes (p=0.001) and increased perceived ability to control blood glucose (p=0.042). Significant correlates to improved glycaemia were male gender (OR=2.655; p=0.034), duration of diabetes >10 years (OR=0.214; p=0.003) and fear of diabetes (OR=0.490; p=0.048). Context-adapted DSME/S introduced in resource-constrained settings and making use of established human resources for health may improve knowledge, attitudes

  9. Estonian and Russian Parental Attitudes to Childrearing and Play.

    Science.gov (United States)

    Saar, Aino; Niglas, Katrin

    2001-01-01

    Used Neukater and van der Kooji's parental attitude questionnaire to ask three groups of mothers (Estonian, non-Estonian in Estonia, Russians in Moscow) about their attitudes toward children's education and play. Found that Estonian mothers applied least control and that higher mother education resulted in less child control and instruction. (DLH)

  10. Cockpit management attitudes

    Science.gov (United States)

    Helmreich, R. L.

    1984-01-01

    Distinctions are drawn between personality traits and attitudes. The stability of the personality and the malleability of attitudes are stressed. These concepts are related to pilot performance, especially in the areas of crew coordination and cockpit resource management. Airline pilots were administered a Cockpit Management Attitudes questionnaire; empirical data from that survey are reported and implications of the data for training in crew coordination are discussed.

  11. A multi-component patient-handling intervention improves attitudes and behaviors for safe patient handling and reduces aggression experienced by nursing staff: A controlled before-after study.

    Science.gov (United States)

    Risør, Bettina Wulff; Casper, Sven Dalgas; Andersen, Lars Louis; Sørensen, Jan

    2017-04-01

    This study evaluated an intervention for patient-handling equipment aimed to improve nursing staffs' use of patient handling equipment and improve their general health, reduce musculoskeletal problems, aggressive episodes, days of absence and work-related accidents. As a controlled before-after study, questionnaire data were collected at baseline and 12-month follow-up among nursing staff at intervention and control wards at two hospitals. At 12-month follow-up, the intervention group had more positive attitudes towards patient-handling equipment and increased use of specific patient-handling equipment. In addition, a lower proportion of nursing staff in the intervention group had experienced physically aggressive episodes. No significant change was observed in general health status, musculoskeletal problems, days of absence or work-related accidents. The intervention resulted in more positive attitudes and behaviours for safe patient-handling and less physically aggressive episodes. However, this did not translate into improved health of the staff during the 12-month study period. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A randomised controlled trial to explore attitudes to routine scale and polish and compare manual versus ultrasonic scaling in the general dental service in Scotland [ISRCTN99609795

    Science.gov (United States)

    Bonner, Brian C; Young, Linda; Smith, Patricia A; McCombes, Wendy; Clarkson, Jan E

    2005-01-01

    Background To investigate, within general dental practice, patients' and vocational dental practitioners' (VDP) attitudes towards the benefits and costs of a simple scale and polish and to compare the experience of using manual versus ultrasonic instruments to scale teeth. Methods 28 VDPs and 420 patients participated. Patients were randomly allocated to either group. Patients' and VDPs' attitudes towards, and experience of, the scale and polish were elicited by means of self-administered questionnaires. Results The majority of patients (99%) believed a scale and polish was beneficial. VDPs considered ultrasonic treatment to be appropriate on significantly more occasions than they did for manual scale and polish (P < 0.001). Patient discomfort: with ultrasonic scaling 69.2% felt 'a little uncomfortable' or worse compared with 60% of those undergoing manual treatment (P = 0.072). VDPs considered treatment charges were appropriate for 77% of patients. Conclusion Routine scaling and polishing is considered beneficial by both patients and vocational trainees. The majority of patients, regardless of treatment method, experience some degree of discomfort when undergoing a scale and polish. VDPs showed a preference for the ultrasonic treatment method. PMID:15975140

  13. Homophobia and attitudes about AIDS.

    Science.gov (United States)

    Dupras, A; Levy, J; Samson, J M; Tessier, D

    1989-02-01

    A random sample of 407 French Canadian adults responded to a questionnaire about perception of AIDS. Negative attitudes about AIDS are better predicted by homophobia than other measures as are attitudes about extramarital relations and attitudes abut adolescent heterosexuality.

  14. Effect of e-cigarette advertisements and antismoking messages on explicit and implicit attitudes towards tobacco and e-cigarette smoking in 18-65-year-olds: a randomised controlled study protocol

    National Research Council Canada - National Science Library

    Paula Booth; Ian P Albery; Daniel Frings

    2017-01-01

    .... Furthermore, little consideration has been given to how viewing online advertisements may have an effect on attitudes towards e-cigarettes or how positive attitudes to e-cigarettes may undermine...

  15. Pornography and Attitude Change

    Science.gov (United States)

    Wallace, Douglas H.; Wehmer, Gerald

    1971-01-01

    The results indicate that a voluntary three hour exposure to erotic pictures, some of which have been defined as being legally obscene," does not lead to a change in a person's attitudes toward such materials or in attitudes toward their censorship. (Author)

  16. Language Learners' Acculturation Attitudes

    Science.gov (United States)

    Rafieyan, Vahid; Orang, Maryam; Bijami, Maryam; Nejad, Maryam Sharafi; Eng, Lin Siew

    2014-01-01

    Learning a language involves knowledge of both linguistic competence and cultural competence. Optimal development of linguistic competence and cultural competence, however, requires a high level of acculturation attitude toward the target language culture. To this end, the present study explored the acculturation attitudes of 70 Iranian…

  17. Asymmetrical international attitudes

    NARCIS (Netherlands)

    Van Oudenhoven, JP; Askevis-Leherpeux, F; Hannover, B; Jaarsma, R; Dardenne, B

    2002-01-01

    In general, attitudes towards nations have a fair amount of reciprocity: nations either like each other are relatively indifferent to each other or dislike each other Sometimes, however international attitudes are asymmetrical. In this study, we use social identity theory in order to explain

  18. Individual Attitudes Towards Trade

    DEFF Research Database (Denmark)

    Jäkel, Ina Charlotte; Smolka, Marcel

    2013-01-01

    Using the 2007 wave of the Pew Global Attitudes Project, this paper finds statistically significant and economically large Stolper-Samuelson effects in individuals’ preference formation towards trade policy. High-skilled individuals are substantially more pro-trade than low-skilled individuals......-Ohlin model in shaping free trade attitudes, relative to existing literature....

  19. Student Attitude toward Entrepreneurship as Affected by Participation in an SBI Program.

    Science.gov (United States)

    Hatten, Timothy S.; Ruhland, Sheila K.

    1995-01-01

    Before and after participating in the Small Business Institute programs, 220 students completed the Entrepreneurial Attitude Orientation. Students with high locus of control and younger students were more likely to form positive attitudes about entrepreneurship. (SK)

  20. Orbit-attitude coupled motion around small bodies: Sun-synchronous orbits with Sun-tracking attitude motion

    Science.gov (United States)

    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.

  1. Association between Knowledge-Attitude-Practices and Control of Blood Glucose, Blood Pressure, and Blood Lipids in Patients with Type 2 Diabetes in Shanghai, China: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Hua Yang

    2017-01-01

    Full Text Available Knowledge-attitude-practices (KAP significantly impact the outcome of self-management in patients with diabetes, yet the association between KAP and the combined control of the levels of blood glucose, blood pressure, and blood lipids in these patients remains uncertain. This community-based cross-sectional study was conducted from December 2014 to December 2016 on 3977 patients with type 2 diabetes in Shanghai. KAP were evaluated using the modified Chinese version of the Diabetes, Hypertension and Hyperlipidemia (DHL Knowledge Instrument, Diabetes Empowerment Scale–Short Form (DES-SF, and Summary of Diabetes Self-Care Activities (SDSCA. Clinical and biochemical measurements were performed at each sampling site. The association between KAP scores and achieving the combined target goal was assessed by multiple logistic regression. Patients having a higher score of knowledge were more likely to achieve the combined target goal. Furthermore, a turning point of knowledge score was found that the possibility of achieving the combined target goal presented a sharp increase when the knowledge score was more than 70. However, the scores of attitude and practices had no significant relations with achieving the combined target goal. Health intervention strategies, especially increasing integrated diabetes knowledge, should be targeted to patients with type 2 diabetes in communities.

  2. The EAST's Injury Control and Violence Prevention Committee's Annual Distracted Driving Outreach Event: Evaluating attitude and behavior change in high school students.

    Science.gov (United States)

    Allee, Lisa; Dechert, Tracey; Rao, Sowmya R; Crandall, Marie; Christmas, Ashley; Eastman, Alexander; Duncan, Thomas; Foster, Shannon

    2017-05-22

    The National Center for Statistics and Analysis report at least 8 deaths and 1,160 daily injuries due to distracted driving (DD) in the U.S. Drivers under age 20 are most likely to incur a distraction related fatal crash. We aimed to determine short and long term impact of a multi-modal educational program including student developed interventions, simulated driving experiences, and presentations by law enforcement and medical personnel. A single day program aimed at teen DD prevention was conducted at a high school targeting students age 15 to 19 years old. Students were surveyed before, after, and at 6 weeks. We surveyed age, gender, knowledge and experience regarding DD. Summary statistics were obtained at each survey time point. Bivariate and multivariable (MV) analysis were conducted to assess whether change in responses varied over time points. MV models were adjusted for sex, urban and rural driving. Pre, post, and 6 week follow up surveys were completed by 359, 272 (76%), and 331 (92%) students respectively. At baseline and 6 week follow-up, the most frequent passenger reported DD behaviors were cell phone 63% (63% at follow-up) and radio use 61% (63%). Similarly, the most frequent driver reported DD behaviors were cell phone 68% (72%) and radio use 79% (80%). When students were asked, 'how likely are you to use your cell phone while driving?', they answered 'never', 35%, 70%, and 46% on the pre, post and 6 week surveys. They were less likely to report consequences to be worse or change in attitude to a great extent at 6 weeks (p<0.01). Gender, urban or rural driving were not significantly associated with responses. While DD education may facilitate short term knowledge and attitude changes, there appears to be no lasting effect. Research should be focused toward strategies for longer term impact. II, therapeutic study STUDY TYPE: Original Article.

  3. Trying to trust: Brain activity during interpersonal social attitude change.

    Science.gov (United States)

    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.

  4. Longitudinal analysis of attitudes toward wolves.

    Science.gov (United States)

    Treves, Adrian; Naughton-Treves, Lisa; Shelley, Victoria

    2013-04-01

    Understanding individual attitudes and how these predict overt opposition to predator conservation or direct, covert action against predators will help to recover and maintain them. Studies of attitudes toward wild animals rely primarily on samples of individuals at a single time point. We examined longitudinal change in individuals' attitudes toward gray wolves (Canis lupus). In the contiguous United States, amidst persistent controversy and opposition, abundances of gray wolves are at their highest in 60 years. We used mailed surveys to sample 1892 residents of Wisconsin in 2001 or 2004 and then resampled 656 of these individuals who resided in wolf range in 2009. Our study spanned a period of policy shifts and increasing wolf abundance. Over time, the 656 respondents increased agreement with statements reflecting fear of wolves, the belief that wolves compete with hunters for deer (Odocoileus virginianus), and inclination to poach a wolf. Endorsement of lethal control of wolves by the state and public hunting of wolves also increased. Neither the time span over which respondents reported exposure to wolves locally nor self-reported losses of domestic animals to wolves correlated with changes in attitude. We predict future increases in legal and illegal killing of wolves that may reduce their abundance in Wisconsin unless interventions are implemented to improve attitudes and behavior toward wolves. To assess whether interventions change attitudes, longitudinal studies like ours are needed. Análisis Longitudinal de las Actitudes Hacia Lobos. © 2013 Society for Conservation Biology.

  5. Adultos livres de cárie: estudo de casos e controles sobre conhecimentos, atitudes e práticas preventivas Adults free of caries: a case-control study about: awareness/consciousness, attitudes and preventive practices

    Directory of Open Access Journals (Sweden)

    Paulo C. Petry

    2000-01-01

    Full Text Available Com o objetivo de investigar o efeito do conhecimento e atitudes pessoais, hábitos de higiene oral e uso de fluoretos sobre a total ausência de cáries, realizou-se um estudo do tipo caso-controle entre estudantes universitários da região sul do Brasil. A análise bruta por regressão logística condicional não demonstrou efeito para as variáveis relacionadas ao uso de fluoretos e hábitos de higiene oral (p > 0,20. Já o uso de fio dental apareceu como um fator de risco: os que afirmaram não usá-lo apresentaram "odds ratio" (OR bruto de 0,70, e de 0,73 quando ajustado para visitas regulares ao dentista. O efeito para as visitas regulares ao dentista foi de risco. Pessoas com história de cárie visitavam mais os profissionais. Aqueles com história de cárie apresentaram um "odds ratio" bruto de 1,55; após o ajuste para uso de fio dental o risco foi levemente superior (OR = 1,67. Hábitos de higiene oral não demonstraram efeito protetor esperado. O uso de fluoretos não esteve significativamente associado à ausência de cáries. Permanece intrigando o fato de que algumas pessoas não desenvolvam cáries, mesmo não relatando cuidados considerados ideais à saúde bucal.The purpose of this article was to investigate the effect of personal awareness and attitudes, the dentist's role, oral hygiene habits, and fluoride use on total absence of caries in adults, using a case-control study matched for sex and age with undergraduate students from two private Brazilian universities. Crude analysis using conditional logistic regression failed to show any effect for the related variables regarding fluoride use and oral hygiene habits (p > 0.20. Use of dental floss was the only exception in this set. It appeared as a risk factor, since individuals who stated not flossing presented a crude odds ratio (OR of 0.70, or 0.73 when adjusted for regular visits to the dentist. The effect for regular visits to the dentist was that of a risk. Those with a

  6. Attitudes Towards Immigration

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Munch, Jakob Roland; Schroll, Sanne

    In this paper, we re-examine the role of economic self-interest in shaping people’s attitudes towards immigration, using data from the European Social Survey 2002/2003. Compared to the existing literature, there are two main contributions of the present paper. First, we develop a more powerful test...... of the hypothesis that a positive relationship between education and attitudes towards immigration reflects economic self-interest in the labour market. Second, we develop an alternative and more direct test of whether economic self-interest matters for people’s attitudes towards immigration. We find that while...

  7. Attitudes Towards Immigration

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Roland Munch, Jakob; Schroll, Sanne

    2006-01-01

    In this paper, we re-examine the role of economic self-interest in shaping people's attitudes towards immigration, using data from the European Social Survey 2002/2003. Compared to the existing literature, there are two main contributions of the present paper. First, we develop a more powerful test...... of the hypothesis that a positive relationship between education and attitudes towards immigration reflects economic self-interest in the labour market. Second, we develop an alternativeand more direct test of whether economic self-interest mattersfor people's attitudes towards immigration. We find that whilethe...

  8. On the generalization of attitude accessibility after repeated attitude expression

    OpenAIRE

    Descheemaeker, Mathilde; Spruyt, Adriaan; Fazio, Russell H.; Hermans, Dirk

    2017-01-01

    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 ...

  9. In-orbit attitude actuation using solar panels

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2008-06-01

    Full Text Available A specific technique is developed to wield the internal disturbance torque caused by the solar panel actuation for spacecraft attitude control tasks. This work is the maiden work towards integrating the attitude control and the solar tracking tasks, forming a combined attitude and solar tracking system. The feasibility of this concept for spacecraft is proven and eventually the combined concept is validated. A technical proof is presented corresponding to the end-to-end system demonstration. The investigation starts with the determination of the solar tracking constraints. Then, the mathematical models describing the attitude and solar tracking are established, and eventually the onboard architecture is implemented. The numerical treatments using MatlabTM were performed to evaluate the developed onboard architecture. The simulation results are discussed especially from the attitude control standpoint. The integrated system complies very well with the reference mission requirements.

  10. On-the Fly Merging of Attitude Solutions

    DEFF Research Database (Denmark)

    Jørgensen, Peter Siegbjørn; Jørgensen, John Leif; Denver, Troelz

    2008-01-01

    of the available information, i.e. optimal accuracy, methods for merging such data should be investigated. The need for and desirability of attitude merging depends on the mission objective and available resources. To enable real-time attitude control and reduce requirements on download budget, on-board merging...... of attitude data will often be advantageous. This should be weighted against the need for post observation reconstruction of attitudes, especially needed when end products are sensitive to optimal attitude reconstruction. Instrument integrated merging algorithms will reduce the complexity of on-board AOCS....... Methods for attitude merging are many. Two examples of merging methods taking into consideration anisotropic noise distributions are presented and discussed....

  11. Peer group socialization of homophobic attitudes and behavior during adolescence.

    Science.gov (United States)

    Poteat, V Paul

    2007-01-01

    A social developmental framework was applied to test for the socialization of homophobic attitudes and behavior within adolescent peer groups (Grades 7-11; aged 12-17 years). Substantial similarity within and differences across groups were documented. Multilevel models identified a group socializing contextual effect, predicting homophobic attitudes and behavior of individuals within the group 8 months later, even after controlling for the predictive effect of individuals' own previously reported attitudes and behavior. Several group characteristics moderated the extent to which individuals' previously reported attitudes predicted later attitudes. Findings indicate the need to integrate the concurrent assessment of individual and social factors to inform the construction of more comprehensive models of how prejudiced attitudes and behaviors develop and are perpetuated.

  12. Does exposure to music videos predict adolescents' sexual attitudes?

    NARCIS (Netherlands)

    Beentjes, J.W.J.; Konig, R.P.

    2013-01-01

    This study investigates whether exposure to music videos predicts adolescents' sexual attitudes when controlled for relevant characteristics of individuals and their social environment. Sexual attitudes are related to their music video use (i.e. exposure to music videos, peer group talk about music

  13. Demand Characteristics in Classical Verbal Conditioning and Attitude Conditioning Studies.

    Science.gov (United States)

    McGinley, Hugh

    This paper is a draft for the American Psychological Association Symposium on the conditioning of verbal behavior and attitudes. The author presents the results of several studies he conducted in the classical conditioning of meaning and attitude. These studies attempt to control the measurement effects created by extraneous variables operating on…

  14. Touchless attitude correction for satellite with constant magnetic moment

    Science.gov (United States)

    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.

  15. Does Exposure to Music Videos Predict Adolescents' Sexual Attitudes?

    NARCIS (Netherlands)

    Beentjes, J.W.J.; Konig, R.P.

    2013-01-01

    This study investigates whether exposure to music videos predicts adolescents' sexual attitudes when controlled for relevant characteristics of individuals and their social environment. Sexual attitudes are related to their music video use (i.e. exposure to music videos, peer group talk about music

  16. Does exposure to music videos predict adolescents’ sexual attitudes?

    NARCIS (Netherlands)

    Beentjes, J.W.J.; Konig, R.P.

    2013-01-01

    This study investigates whether exposure to music videos predicts adolescents' sexual attitudes when controlled for relevant characteristics of individuals and their social environment. Sexual attitudes are related to their music video use (i.e. exposure to music videos, peer group talk about music

  17. Explicit- and implicit bullying attitudes in relation to bullying behavior

    NARCIS (Netherlands)

    van Goethem, A.A.J.; Scholte, R.H.J.; Wiers, R.W.

    2010-01-01

    The main aim of this study was to examine whether an assessment of implicit bullying attitudes could add to the prediction of bullying behavior after controlling for explicit bullying attitudes. Primary school children (112 boys and 125 girls, M age = 11 years, 5 months) completed two newly

  18. Explicit- and Implicit Bullying Attitudes in Relation to Bullying Behavior

    NARCIS (Netherlands)

    Goethem, A.A.J. van; Scholte, R.H.J.; Wiers, R.W.H.J.

    2010-01-01

    The main aim of this study was to examine whether an assessment of implicit bullying attitudes could add to the prediction of bullying behavior after controlling for explicit bullying attitudes. Primary school children (112 boys and 125 girls, M age = 11 years, 5 months) completed two newly

  19. ABFAB. Attachment to the breast and family attitudes to breastfeeding. The effect of breastfeeding education in the middle of pregnancy on the initiation and duration of breastfeeding: a randomised controlled trial [ISRCTN21556494

    Directory of Open Access Journals (Sweden)

    Waldenström Ulla

    2003-08-01

    Full Text Available Abstract Background It has proven difficult to reach World Health Organization (WHO recommendations that infants be exclusively breastfed from birth to six months of age 12, yet there is limited knowledge about interventions that are effective in increasing breastfeeding initiation and duration. Particularly lacking is evidence about how to maintain breastfeeding rates in countries which already have a high initiation of breastfeeding. This study aims to determine whether mid-pregnancy breastfeeding education, with a focus on either attitudes to breastfeeding or on technical aspects of breastfeeding, has an effect on rates of breastfeeding initiation and duration. Secondary aims of the study are to: explore what factors might affect the duration of breastfeeding and evaluate the interventions from the participant and childbirth facilitator perspectives. Methods/Design A randomised controlled trial (RCT design will be used. Women having their first baby, and planning to give birth as public patients at the Royal Women's Hospital (RWH, Melbourne, will be approached at 18–20 weeks of pregnancy and invited to participate in the study. Participants will be randomly allocated to a control group or one of two group interventions: a previously designed and trialled tool to teach practical aspects of breastfeeding or an exploration of family attitudes to breastfeeding. The latter was developed and piloted by the investigators in conjunction with the group facilitators, prior to trial commencement. The interventions are planned to take place at 20–25 weeks. Data will be collected by questionnaire at recruitment, at interview in hospital after the birth and by telephone interview six months later. Medical/obstetric outcomes will be obtained from the medical record. The sample size (972 was calculated to identify an increase in breastfeeding initiation from 75 to 85% and an increase from 40 to 50% in breastfeeding at six months.

  20. Effectiveness of a virtual intervention for primary healthcare professionals aimed at improving attitudes towards the empowerment of patients with chronic diseases: study protocol for a cluster randomized controlled trial (e-MPODERA project).

    Science.gov (United States)

    González-González, Ana Isabel; Orrego, Carola; Perestelo-Perez, Lilisbeth; Bermejo-Caja, Carlos Jesús; Mora, Nuria; Koatz, Débora; Ballester, Marta; Del Pino, Tasmania; Pérez-Ramos, Jeannet; Toledo-Chavarri, Ana; Robles, Noemí; Pérez-Rivas, Francisco Javier; Ramírez-Puerta, Ana Belén; Canellas-Criado, Yolanda; Del Rey-Granado, Yolanda; Muñoz-Balsa, Marcos José; Becerril-Rojas, Beatriz; Rodríguez-Morales, David; Sánchez-Perruca, Luis; Vázquez, José Ramón; Aguirre, Armando

    2017-10-30

    Communities of practice are based on the idea that learning involves a group of people exchanging experiences and knowledge. The e-MPODERA project aims to assess the effectiveness of a virtual community of practice aimed at improving primary healthcare professional attitudes to the empowerment of patients with chronic diseases. This paper describes the protocol for a cluster randomized controlled trial. We will randomly assign 18 primary-care practices per participating region of Spain (Catalonia, Madrid and Canary Islands) to a virtual community of practice or to usual training. The primary-care practice will be the randomization unit and the primary healthcare professional will be the unit of analysis. We will need a sample of 270 primary healthcare professionals (general practitioners and nurses) and 1382 patients. We will perform randomization after professionals and patients are selected. We will ask the intervention group to participate for 12 months in a virtual community of practice based on a web 2.0 platform. We will measure the primary outcome using the Patient-Provider Orientation Scale questionnaire administered at baseline and after 12 months. Secondary outcomes will be the sociodemographic characteristics of health professionals, sociodemographic and clinical characteristics of patients, the Patient Activation Measure questionnaire for patient activation and outcomes regarding use of the virtual community of practice. We will calculate a linear mixed-effects regression to estimate the effect of participating in the virtual community of practice. This cluster randomized controlled trial will show whether a virtual intervention for primary healthcare professionals improves attitudes to the empowerment of patients with chronic diseases. ClicalTrials.gov, NCT02757781 . Registered on 25 April 2016. Protocol Version. PI15.01 22 January 2016.

  1. Attitudes towards recreational hunting

    DEFF Research Database (Denmark)

    Gamborg, Christian; Jensen, Frank Søndergaard

    2017-01-01

    a negative attitude to recreational hunting. Older respondents and rural residents had more positive attitudes towards hunting than younger and urban residents. Some of the conditions under which hunting occurs affected attitudes negatively, especially the hunting of farm-reared and released game birds...... to the commercial aspect of hunting and this could result in tighter regulation with further effects on management practices. Management Implications The public opinions and public preferences concerning recreational hunting are complex. However, this study revealed some factors relevant for regulatory...... and managerial development in relation to outdoor recreation: age (younger respondents were least supportive of hunting), urbanisation (living in an urban environment enhanced negative attitudes), compatibility of recreational hunting with other outdoor leisure activities....

  2. Spacecraft Attitude Determination

    DEFF Research Database (Denmark)

    Bak, Thomas

    determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude......This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

  3. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  4. Attitudes towards immigration

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Munch, Jakob Roland; Skaksen, Jan Rose

    2008-01-01

    Using the European Social Survey 2002/3, we develop a new test of whether economic self-interest influences people's attitudes towards immigration, exploiting that people have widely different perceptions of the consequences of immigration......Using the European Social Survey 2002/3, we develop a new test of whether economic self-interest influences people's attitudes towards immigration, exploiting that people have widely different perceptions of the consequences of immigration...

  5. Consumers' attitudes towards sonic logos

    OpenAIRE

    Shi, Qichao

    2012-01-01

    Sonic logos are increasingly being used as a way of sonic branding in marketing activities. Scholars have acknowledged the benefits of sonic logos, such as communicating brand attributes to consumers. However, studies about consumers’ attitudes towards sonic logos are scarce. This paper examined consumers’ attitudes towards sonic logos, particularly how cognitive and affective elements correlated with such attitudes, whether such attitudes had correlations with consumers’ attitudes towards th...

  6. Implicit and Explicit Attitudes Toward Sex and Romance in Asexuals.

    Science.gov (United States)

    Bulmer, Maria; Izuma, Keise

    2017-03-31

    Despite the recent surge of interest in sexuality, asexuality has remained relatively underresearched. Distinct from abstinence or chastity, asexuality refers to a lack of sexual attraction toward others. Past research suggests asexuals have negative attitudes toward sex, though no research has examined implicit attitudes. While preliminary evidence suggests that many asexuals are interested in engaging in romantic relationships, these attitudes have yet to be examined thoroughly, implicitly, or compared with a control group. This study investigated explicit and implicit attitudes toward sex and romance in a group of asexuals (N = 18, age M = 21.11) and a group of controls (N = 27, age M = 21.81), using the Asexuality Identification Scale (AIS), the Triangular Love Scale (TLS), semantic differentials, an Implicit Association Task (IAT), and two Single Category IATs. It was found that asexuals exhibited more negative explicit and implicit attitudes toward sex, as well as more negative explicit attitudes toward romance, relative to controls. There was no significant difference between groups on implicit romantic attitudes. Moreover, aromantic asexuals demonstrated significantly more negative explicit attitudes toward romance than romantic asexuals, though there was no significant difference between groups on implicit measures. Explanations and implications of these findings are discussed.

  7. Effects of Brain-Based Learning Approach on Students' Motivation and Attitudes Levels in Science Class

    Science.gov (United States)

    Akyurek, Erkan; Afacan, Ozlem

    2013-01-01

    The purpose of the study was to examine the effect of brain-based learning approach on attitudes and motivation levels in 8th grade students' science classes. The main reason for examining attitudes and motivation levels, the effect of the short-term motivation, attitude shows the long-term effect. The pre/post-test control group research model…

  8. Effect of a Nutrition Education Program on the Eating Attitudes and Behaviors of College Women.

    Science.gov (United States)

    Koszewski, Wanda M.; And Others

    1990-01-01

    Examined the effects of a nutrition education program on the eating attitudes and behaviors of college women (N= 130). Experimental and control groups completed pre- and posttest assessments of nutrition knowledge, attitudes, and eating behaviors. Findings showed that the nutrition education program positively affected the attitudes and eating…

  9. The Effects of the Cognitive-Behavioral Marriage Enrichment Program on the Dysfunctional Attitudes of Couples

    Science.gov (United States)

    Kalkan, Melek; Ersanli, Ercumend

    2009-01-01

    The aim of this study is to investigate the effectiveness of cognitive-behavioral marriage enrichment program to decrease the level of the dysfunctional attitudes of the couples. Forty participants with dysfunctional attitudes determined by The Dysfunctional Attitude Scale were randomly chosen as experimental and control groups. The results of the…

  10. The Effects of Attitudes on Teenage Premarital Pregnancy and Its Resolution.

    Science.gov (United States)

    Plotnick, Robert D.

    1992-01-01

    Studies the influence of self-esteem, locus of control, attitudes toward women's family roles, attitudes toward school, educational aspirations, and religiosity on the probability of teenage premarital pregnancy and its resolution. Results for 1,142 white adolescent girls show that self-esteem and attitudes toward schooling and family roles were…

  11. Knowledge, Attitude and Practices of Vector-Borne Disease Prevention during the Emergence of a New Arbovirus: Implications for the Control of Chikungunya Virus in French Guiana.

    Science.gov (United States)

    Fritzell, Camille; Raude, Jocelyn; Adde, Antoine; Dusfour, Isabelle; Quenel, Philippe; Flamand, Claude

    2016-11-01

    During the last decade, French Guiana has been affected by major dengue fever outbreaks. Although this arbovirus has been a focus of many awareness campaigns, very little information is available about beliefs, attitudes and behaviors regarding vector-borne diseases among the population of French Guiana. During the first outbreak of the chikungunya virus, a quantitative survey was conducted among high school students to study experiences, practices and perceptions related to mosquito-borne diseases and to identify socio-demographic, cognitive and environmental factors that could be associated with the engagement in protective behaviors. A cross-sectional survey was administered in May 2014, with a total of 1462 students interviewed. Classrooms were randomly selected using a two-stage selection procedure with cluster samples. A multiple correspondence analysis (MCA) associated with a hierarchical cluster analysis and with an ordinal logistic regression was performed. Chikungunya was less understood and perceived as a more dreadful disease than dengue fever. The analysis identified three groups of individual protection levels against mosquito-borne diseases: "low" (30%), "moderate" (42%) and "high" (28%)". Protective health behaviors were found to be performed more frequently among students who were female, had a parent with a higher educational status, lived in an individual house, and had a better understanding of the disease. This study allowed us to estimate the level of protective practices against vector-borne diseases among students after the emergence of a new arbovirus. These results revealed that the adoption of protective behaviors is a multi-factorial process that depends on both sociocultural and cognitive factors. These findings may help public health authorities to strengthen communication and outreach strategies, thereby increasing the adoption of protective health behaviors, particularly in high-risk populations.

  12. Attitudes of Children Established by Classical Conditioning.

    Science.gov (United States)

    Barnabei, Fred; And Others

    This study examined the attitudes of children established by classical conditioning. Subjects were 4th graders (26 males and 31 females). Each child was randomly assigned to either an experimental or a control group. A posttest-only design was used with positive and negative word associations presented to the experimental group, and neutral word…

  13. Optimal attitude corrections for cylindrical spacecraft

    Science.gov (United States)

    Zanardi, M. C.; Santos, R. M. K.; da Silva Fernandes, S.

    2003-04-01

    A first order analytical model for optimal small amplitude attitude maneuvers of spacecraft with cylindrical symmetry in an elliptical orbits is presented. The optimization problem is formulated as a Mayer problem with the control torques provided by a power limited propulsion system. The state is defined by Serret-Andoyer's variables and the control by the components of the propulsive torques. The Pontryagin Maximum Principle is applied to the problem and the optimal torques are given explicitly in Serret-Andoyer's variables and their adjoints. For small amplitude attitude maneuvers, the optimal Hamiltonian function is linearized around a reference attitude. A complete first order analytical solution is obtained by simple quadrature and is expressed through a linear algebraic system involving the initial values of the adjoint variables. A numerical solution is obtained by taking the Euler angles formulation of the problem, solving the two-point boundary problem through the shooting method, and, then, determining the Serret-Andoyer variables through Serret-Andoyer transformation. Numerical results show that the first order solution provides a good approximation to the optimal control law and also that is possible to establish an optimal control law for the artificial satellite's attitude.

  14. Participation in Adult Education: Attitudes and Barriers

    Science.gov (United States)

    Boeren, Ellen

    2011-01-01

    In this paper, we control the intention theory of Fishbein and Ajzen (1980) for the participation in an adult education course. Based on the Flemish Eurostat Adult Education Survey, we reveal that participants in adult education have a more positive attitude towards learning and that within the group of non-participants, those who formulate an…

  15. Scaling of Attitudes Toward Population Problems

    Science.gov (United States)

    Watkins, George A.

    1975-01-01

    This study related population problem attitudes and socioeconomic variables. Six items concerned with number of children, birth control, family, science, economic depression, and overpopulation were selected for a Guttman scalogram. Education, occupation, and number of children were correlated with population problems scale scores; marital status,…

  16. Implicit attitudes among trainee and qualified clinical psychologists in the UK

    OpenAIRE

    Blenclowe, Alison

    2017-01-01

    Implicit attitudes are thoughts and feelings that occur outside of conscious awareness and are therefore difficult to acknowledge and control. Implicit attitudes have been shown to predict socially sensitive intergroup behaviour not predicted by self-reported (explicit) attitudes. Consequently, negative attitudes towards certain demographic groups (e.g. women, older people, minority ethnic groups, gay people) may contribute to persistent disparities in employment, criminal justice, education ...

  17. Self-reported practices and attitudes of community health workers (accredited social health activist in tobacco control - Findings from two states in India

    Directory of Open Access Journals (Sweden)

    Divya Persai

    2015-01-01

    Conclusions: Study findings reflect suboptimal engagement of ASHAs in providing information pertaining to specific tobacco-related diseases. There is an urgent need to sensitize and train ASHAs in appropriate tobacco control practices.

  18. Attitude towards, and likelihood of, complaining in the banking ...

    African Journals Online (AJOL)

    Attitude towards complaining in the banking, domestic airline and restaurant ... who experience a service failure in the best possible way (Robinson et al. ... Rand Bank (the largest banks in sub-Saharan Africa), ABSA (with the controlling.

  19. Parents' perception, students' and teachers' attitude towards school sex education

    National Research Council Canada - National Science Library

    Fentahun, Netsanet; Assefa, Tsion; Alemseged, Fessahaye; Ambaw, Fentie

    2012-01-01

    ...) and how to avoid them, and birth control methods. This study was conducted to explore perception of parents about school sex education and assess the attitude of teachers and students towards school sex education...

  20. Attitudes towards poverty

    Directory of Open Access Journals (Sweden)

    Andrzej Derdziuk

    2015-04-01

    Full Text Available Poverty, perceived as a lack of basic consumer goods, gives rise to a whole range of outcomes which affect not only the material dimension of human existence, but also influence social relations and references to spiritual values. Attitudes which could be associated with involuntary and unacceptable poverty include: doubt in the Divine Providence, bitterness, jealousy and envy, blaming others, lack of gratitude and in perceiving good, laziness, lack of initiative, escalating demands, gluttony and greed as well as meanness. However, joy, peace, freedom and solidarity with the poor, as well as work and enterprise, are symptoms of evangelical attitudes of the poor in spirit. Attitudes to poverty point to a wide range of human behaviours towards possessions and in effect, reveal an individual’s sense of value.