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Alimentação fora do domicilio : a atitude do consumidor frente a informação nutricional dos alimentos disponibilizada por restaurantes, Campinas - SP.; Food away from home : the attitude of the consumer towards the nutritional information of food available in restaurants, Campinas - SP.

Michele Sanches
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/05/2007 Português
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Ha um extenso rol de evidencias cientificas revelando um aumento no consumo de alimentos fora do domicilio. Dessa forma, o fornecimento das informacoes nutricionais pelos restaurantes constitui-se numa ferramenta que pode auxiliar os individuos a realizarem suas escolhas alimentares (fora de casa) de maneira mais consciente. Os objetivos principais da presente pesquisa sao: identificar a frequencia de consumo das refeicoes realizadas fora do domicilio pelos consumidores, avaliar a atitude no tocante a informacao nutricional disponibilizada em restaurantes, determinar o nivel do conhecimento nutricional e identificar associacoes estatisticamente significativas entre a atitude, o conhecimento e variaveis socioeconomicas e demograficas dos individuos. Este estudo foi conduzido com 250 consumidores adultos (125 de cada genero) residentes no municipio de Campinas (SP). O instrumento utilizado foi um questionario previamente testado. Para avaliar a atitude dos entrevistados elaborou-se uma escala Likert. A fim de identificar o nivel do conhecimento nutricional usou-se um questionario composto por 56 questoes referentes ao conhecimento dos alimentos fontes de alguns nutrientes e da relação entre dieta-doenca. A identificacao da atitude referente as informacoes nutricionais disponibilizadas nos restaurantes foi feita atraves do calculo da media...

Atitude do consumidor em relação à certificação voluntária da segurança dos alimentos em restaurantes comerciais, município de Campinas-SP; Consumer attitudes with respect to voluntary certification of food safety in commercial restaurants, municipality of Campinas - SP

Paula Lazzarin Uggioni
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/07/2011 Português
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O consumo alimentar fora de casa é relevante para vários segmentos populacionais. Paralelamente, a ocorrência de doenças transmitidas por alimentos representa um problema de saúde pública, tanto em países desenvolvidos como em países em desenvolvimento. Os restaurantes são frequentemente indicados como locais de ocorrência desse tipo de doenças e entre as causas principais, podem-se citar falhas no processo produtivo dos alimentos. Nesse cenário, surgem os certificados de qualidade, que visam, além da melhoria dos processos produtivos em restaurantes, informar os consumidores sobre os aspectos intrínsecos de segurança dos alimentos. Destaca-se ainda que a análise da atitude e do conhecimento dos consumidores em relação à segurança dos alimentos pode se configurar como ferramenta para auxiliar nesse processo (uma vez que atitude e conhecimento são fenômenos interligados), contribuindo para o entendimento do comportamento do consumidor. Assim, o objetivo deste estudo foi analisar a atitude dos consumidores em relação à certificação voluntária da segurança dos alimentos em restaurantes, verificando a sua relação com as variáveis socioeconômicas e demográficas e com o conhecimento sobre os riscos microbiológicos das práticas em restaurantes. Para tanto...

The Time for Doing is Not the Time for Change: Effects of General Action and Inaction Goals on Attitude Retrieval and Attitude Change

Albarracín, Dolores; Handley, Ian M.
Tipo: text
Publicado em /06/2011 Português
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Implicit in many informal and formal principles of psychological change is the understudied assumption that change requires either an active approach or an inactive approach. This issue was systematically investigated by comparing the effects of general action goals and general inaction goals on attitude change. As prior attitudes facilitate preparation for an upcoming persuasive message, general action goals were hypothesized to facilitate conscious retrieval of prior attitudes and therefore hinder attitude change to a greater extent than general inaction goals. Experiment 1 demonstrated that action primes (e.g., “go,” “energy”) yielded faster attitude report than inaction primes (e.g., “rest,” “still”) among participants who were forewarned of an upcoming persuasive message. Experiment 2 showed that the faster attitude report identified in Experiment 1 was localized on attitudes towards a message topic participants were prepared to receive. Experiments 3, 4, and 5 showed that, compared to inaction primes, action primes produced less attitude change and less argument scrutiny in response to a counterattitudinal message on a previously forewarned topic. Experiment 6 confirmed that the effects of the primes on attitude change were due to differential attitude retrieval. That is...

Iranian Pharmacists’ Knowledge, Attitude and Practice Regarding Counterfeit Drugs

Shahverdi, Shieda; Hajimiri, Mirhamed; Pourmalek, Farshad; Torkamandi, Hassan; Gholami, Kheirollah; Hanafi, Somayeh; Ashrafi Shahmirzadi, Nikinaz; Javadi, Mohammadreza
Fonte: Shaheed Beheshti University of Medical Sciences Publicador: Shaheed Beheshti University of Medical Sciences
Tipo: text
Publicado em //2012 Português
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Background Awareness of pharmacists about counterfeit drugs is necessary for health improvement in community. The purpose of the present study is to assess the knowledge and measure the professional attitude and practice of Iranian pharmacist about counterfeit drugs. In August 2008, a knowledge, attitude and practice (KAP) study was performed in a national sample of 794 pharmacists who participated in an Iranian Pharmacist Association congress. A questionnaire was prepared to collect Demographic and professional characteristics, Knowledge, attitude and practice of pharmacists regarding counterfeit drugs. The mean percent of participants who answer each practice questions correctly is 13.62% and none of questions have more than 14.7% of correct answer, while the participants’ attitude towards the subject is at high level. None of demographic factors represented a significant relationship with knowledge and the only related parameters with attitude, were age and gender. Increasing age of pharmacists resulted in attitude improvement (p = 0.013) and women›s attitudes were better than men (p = 0.05).The only related parameters with practice, were the number of working hours per a week and attitude. Increasing the number of working hours per a week...

On the Relationship between the Indirectly Measured Attitude Towards Beer and Beer Consumption: The Role of Attitude Accessibility

Descheemaeker, Mathilde; Spruyt, Adriaan; Hermans, Dirk
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: text
Publicado em 28/04/2014 Português
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Although some studies have demonstrated that the indirectly measured attitude towards alcohol is related to alcohol use, this relationship has not always been confirmed. In the current study, we attempted to shed light on this issue by investigating whether the predictive validity of an indirect attitude measure is dependent upon attitude accessibility. In a sample of 88 students, the picture-picture naming task, an adaptation of the affective priming paradigm, was used to measure the automatically activated attitude towards beer. Attitude accessibility was measured using a speeded evaluative categorization task. Behavioral measures were the amount of beer poured and drunk during a bogus taste test and the choice between a bottle of beer or water at the end of the experiment. In line with our hypothesis, the indirectly measured attitude towards beer predicted behavior during the taste test only when it was highly accessible. In contrast, this attitude was related to choice behavior irrespective of attitude accessibility. This study confirms that indirect attitude measures can be valuable predictors of alcohol-related behavior, but that it is sometimes necessary to take attitude accessibility into account.

The Inertial Attitude Augmentation for Ambiguity Resolution in SF/SE-GNSS Attitude Determination

Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping
Fonte: MDPI Publicador: MDPI
Tipo: text
Publicado em 26/06/2014 Português
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The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that...

A Dynamic Attitude Measurement System Based on LINS

Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun
Fonte: MDPI Publicador: MDPI
Tipo: text
Publicado em 29/08/2014 Português
Relevância na Pesquisa
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A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20? (1?) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min.

Attitude determination with three-axis accelerometer for emergency atmospheric entry

Garcia-Llama, Eduardo
Formato: application/pdf
Português
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Two algorithms are disclosed that, with the use of a 3-axis accelerometer, will be able to determine the angles of attack, sideslip and roll of a capsule-type spacecraft prior to entry (at very high altitudes, where the atmospheric density is still very low) and during entry. The invention relates to emergency situations in which no reliable attitude and attitude rate are available. Provided that the spacecraft would not attempt a guided entry without reliable attitude information, the objective of the entry system in such case would be to attempt a safe ballistic entry. A ballistic entry requires three controlled phases to be executed in sequence: First, cancel initial rates in case the spacecraft is tumbling; second, maneuver the capsule to a heat-shield-forward attitude, preferably to the trim attitude, to counteract the heat rate and heat load build up; and third, impart a ballistic bank or roll rate to null the average lift vector in order to prevent prolonged lift down situations. Being able to know the attitude, hence the attitude rate, will allow the control system (nominal or backup, automatic or manual) to cancel any initial angular rates. Also, since a heat-shield forward attitude and the trim attitude can be specified in terms of the angles of attack and sideslip...

Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

Zhou, Zhiqiang
Tipo: lar-17862-1; nasa tech briefs, january 2012; 40 Formato: application/pdf
Português
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A paper describes attitude-control algorithms using the combination of magnetic actuators with reaction wheel assemblies (RWAs) or other types of actuators such as thrusters. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for nadir-pointing, pitch, and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude- control accuracy is comparable with RWA-based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude-control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode, and the control accuracy can be maintained. The attitude-control algorithms of the combined actuators are derived, which can guarantee the spacecraft attitude and rates to track the commanded values precisely. Results show that precise attitude tracking can be reached, and the attitude-control accuracy is comparable with 3-axis wheel control.

Docking Offset Between the Space Shuttle and the International Space Station and Resulting Impacts to the Transfer of Attitude Reference and Control

Pohlkamp, Kara M.; Helms, W. Jason
Tipo: jsc-cn-22871; jsc-cn-24274; jsc-cn-22593; aiaa space 2011 conference and exposition; 26-29 sep. 2011; long beach, ca; united states Formato: application/pdf
Português
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27%
The Space Shuttle does not dock at an exact 90 degrees to the International Space Station (ISS) x-body axis. This offset from 90 degrees, along with error sources within their respective attitude knowledge, causes the two vehicles to never completely agree on their attitude, even though they operate as a single, mated stack while docked. The docking offset can be measured in flight when both vehicles have good attitude reference and is a critical component in calculations to transfer attitude reference from one vehicle to another. This paper will describe how the docking offset and attitude reference errors between both vehicles are measured and how this information would be used to recover Shuttle attitude reference from ISS in the event of multiple failures. During STS-117, ISS on-board Guidance, Navigation and Control (GNC) computers began having problems and after several continuous restarts, the systems failed. The failure took the ability for ISS to maintain attitude knowledge. This paper will also demonstrate how with knowledge of the docking offset, the contingency procedure to recover Shuttle attitude reference from ISS was reversed in order to provide ISS an attitude reference from Shuttle. Finally, this paper will show how knowledge of the docking offset can be used to speed up attitude control handovers from Shuttle to ISS momentum management. By taking into account the docking offset...

Attitude Estimation in Fractionated Spacecraft Cluster Systems

Blackmore, James C.; Hadaegh, Fred Y.
Tipo: npo-46962; nasa tech briefs, january 2011; 28 Formato: application/pdf
Português
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An attitude estimation was examined in fractioned free-flying spacecraft. Instead of a single, monolithic spacecraft, a fractionated free-flying spacecraft uses multiple spacecraft modules. These modules are connected only through wireless communication links and, potentially, wireless power links. The key advantage of this concept is the ability to respond to uncertainty. For example, if a single spacecraft module in the cluster fails, a new one can be launched at a lower cost and risk than would be incurred with onorbit servicing or replacement of the monolithic spacecraft. In order to create such a system, however, it is essential to know what the navigation capabilities of the fractionated system are as a function of the capabilities of the individual modules, and to have an algorithm that can perform estimation of the attitudes and relative positions of the modules with fractionated sensing capabilities. Looking specifically at fractionated attitude estimation with startrackers and optical relative attitude sensors, a set of mathematical tools has been developed that specify the set of sensors necessary to ensure that the attitude of the entire cluster ( cluster attitude ) can be observed. Also developed was a navigation filter that can estimate the cluster attitude if these conditions are satisfied. Each module in the cluster may have either a startracker...

Spacecraft Attitude Tracking and Maneuver Using Combined Magnetic Actuators

Zhou, Zhiqiang
Tipo: aiaa paper 2010-7899; nf1676l-10005; aiaa guidance, navigation and control conference; 2-5 aug. 2010; toronto; canada Formato: application/pdf
Português
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26.94%
The accuracy of spacecraft attitude control using magnetic actuators only is low and on the order of 0.4-5 degrees. The key reason is that the magnetic torque is two-dimensional and it is only in the plane perpendicular to the magnetic field vector. In this paper novel attitude control algorithms using the combination of magnetic actuators with Reaction Wheel Assembles (RWAs) or other types of actuators, such as thrusters, are presented. The combination of magnetic actuators with one or two RWAs aligned with different body axis expands the two-dimensional control torque to three-dimensional. The algorithms can guarantee the spacecraft attitude and rates to track the commanded attitude precisely. A design example is presented for Nadir pointing, pitch and yaw maneuvers. The results show that precise attitude tracking can be reached and the attitude control accuracy is comparable with RWAs based attitude control. The algorithms are also useful for the RWAs based attitude control. When there are only one or two workable RWAs due to RWA failures, the attitude control system can switch to the control algorithms for the combined magnetic actuators with the RWAs without going to the safe mode and the control accuracy can be maintained.

Staggering Inflation To Stabilize Attitude of a Solar Sail

West, John; Quadrelli, Marco
Tipo: npo-42176; nasa tech briefs, february 2007; 29 Formato: application/pdf
Português
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A document presents computational-simulation studies of a concept for stabilizing the attitude of a spacecraft during deployment of such structures as a solar sail or other structures supported by inflatable booms. Specifically, the solar sail considered in this paper is a square sail with inflatable booms and attitude control vanes at the corners. The sail inflates from its stowed configuration into a square sail with four segments and four vanes at the tips. Basically, the concept is one of controlling the rates of inflation of the booms to utilize in mass-distribution properties to effect changes in the system s angular momentum. More specifically, what was studied were the effects of staggering inflation of each boom by holding it at constant length for specified intervals between intervals of increasing length until full length is reached. The studies included sensitivity analyses of effects of variations in mass properties, boom lengths, rates of increase in boom length, initial rates of rotation of the spacecraft, and several asymmetries that could arise during deployment. The studies led to the conclusion that the final attitude of the spacecraft could be modified by varying the parameters of staggered inflation. Computational studies also showed that by feeding back attitude and attitude-rate measurements so that corrective action is taken during the deployment...

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

Alaniz, Abran; Chamitoff, Greg; McCants, Edward; Bhatt, Sagar; Nguyen, Louis; Bedrossian, Nazareth
Tipo: 31st annual american astronomical society gn&c meeting; 1-6 feb. 2008; breckenridge, co; united states Formato: application/pdf
Português
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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.

Adaptive mass expulsion attitude control system

Rodden, John J.; Stevens, Homer D.; Carrou, Stephane
Formato: application/pdf
Português
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An attitude control system and method operative with a thruster controls the attitude of a vehicle carrying the thruster, wherein the thruster has a valve enabling the formation of pulses of expelled gas from a source of compressed gas. Data of the attitude of the vehicle is gathered, wherein the vehicle is located within a force field tending to orient the vehicle in a first attitude different from a desired attitude. The attitude data is evaluated to determine a pattern of values of attitude of the vehicle in response to the gas pulses of the thruster and in response to the force field. The system and the method maintain the attitude within a predetermined band of values of attitude which includes the desired attitude. Computation circuitry establishes an optimal duration of each of the gas pulses based on the pattern of values of attitude, the optimal duration providing for a minimal number of opening and closure operations of the valve. The thruster is operated to provide gas pulses having the optimal duration.

Motion models in attitude estimation

Sedlak, J.; Wheeler, Z.; Chu, D.
Tipo: nasa. goddard space flight center, flight mechanics(estimation theory symposium, 1994; p 545-557 Formato: application/pdf
Português
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Attitude estimator use observations from different times to reduce the effects of noise. If the vehicle is rotating, the attitude at one time needs to be propagated to that at another time. If the vehicle measures its angular velocity, attitude propagating entails integrating a rotational kinematics equation only. If a measured angular velocity is not available, torques can be computed and an additional rotational dynamics equation integrated to give the angular velocity. Initial conditions for either of these integrations come from the estimation process. Sometimes additional quantities, such as gyro and torque parameters, are also solved for. Although the partial derivatives of attitude with respect to initial attitude and gyro parameters are well known, the corresponding partial derivatives with respect to initial angular velocity and torque parameters are less familiar. They can be derived and computed numerically in a way that is analogous to that used for the initial attitude and gyro parameters. Previous papers have demonstrated the feasibility of using dynamics models for attitude estimation but have not provided details of how each angular velocity and torque parameters can be estimated. This tutorial paper provides some of that detail...

Accuracy study of the Upper Atmosphere Research Satellite (UARS) definitive attitude determination

Snow, Frank; Krack, Kenneth; Bosl, William; Sheu, Yi-Tsuei
Tipo: flight mechanics(estimation theory symposium 1988; p 26-41 Formato: application/pdf
Português
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The Upper Atmosphere Research Satellite (UARS) has two definitive attitude determination requirements: the definitive attitude of the Modular Attitude Control Subsystem (MACS) and the definitive attitude of the gimbaled Solar-Stellar Pointing Platform (SSPP). The onboard computer (OBC) will compute the MACS attitude using a Kalman filter and will transform this attitude solution through the SSPP gimbals to calculate the SSPP attitude. The attitude ground support system (AGSS) will compute the MACS attitude using a batch least-squares differential corrector algorithm and will also transform this solution through the gimbals to obtain the SSPP attitude. This paper reports the results of a prelaunch study to predict the accuracy of the OBC attitude solutions and the accuracy of the AGSS attitude solutions. The OBC and AGSS solution accuracies are then compared to establish the relative quality. The effects of star observability, sensor noise, and sensor misalignment uncertainties on attitude determination accuracy are analyzed for each case.