المؤلفون: Pagà Peris, Roger

المساهمون: University/Department: Universitat Pompeu Fabra. Departament d'Economia i Empresa

مرشدي الرسالة: Baucells, Manel, Cornelissen, Gert

المصدر: TDX (Tesis Doctorals en Xarxa)

مصطلحات موضوعية: Self-regulation, Self-control, Ego depletion, Velocity feedback, Money, Priming, Life meaning, Consumption rituals, Attitudinal similarity, Interpersonal attraction, Auto-regulación, Auto-control, Dinero, Primado, Sentido de la vida, Rituales de consumo, Semejanza actitudinal, Atracción interpersonal

الوصف: The present thesis focuses on three topics within the domain of consumer behavior: self-regulation, the psychological consequences of money, and consumption rituals. The first chapter, devoted to self-regulation, presents a new moderator for the ego depletion effect: velocity feedback. Velocity feedback refers to the perceived speed at which a goal is attained. Three laboratory experiments show that fast velocity feedback can prevent the ego depletion effect and that slower-than-expected velocity feedback can create the ego depletion effect. The second chapter, devoted to the psychological consequences of money, explores the surprising relationship between reminders of money abundance and life meaningfulness. Two laboratory experiments show that individuals who have been reminded of money report having a more meaningful life. This relationship is shown to be fully mediated by self-esteem. The third chapter, devoted to consumption rituals, explores the effect of sharing a consumption ritual on interpersonal attraction. Two laboratory experiments show that when people follow a consumption ritual, they evaluate others who follow the same ritual more positively: an appreciation effect. The appreciation effect was found to be partially mediated by one's feelings of pride, and moderated by whether the target person enjoys the product associated to the ritual.

الوصف (مترجم): Esta tesis se centra en tres temas de la literatura sobre comportamiento del consumidor: la auto-regulación, las consecuencias psicológicas del dinero, y los rituales de consumo. El primer capítulo, dedicado a la auto-regulación, presenta un nuevo moderador para el efecto de ego depletion: velocity feedback. Se entiende por velocity feedback la rapidez percibida con la que se alcanza una meta u objetivo. Tres experimentos de laboratorio muestran que el efecto de ego depletion puede ser neutralizado por una velocity feedback elevada pero generado por una velocity feedback más lenta de lo previsto. El segundo capítulo, dedicado a las consecuencias psicológicas del dinero, explora la sorprendente relación entre los recordatorios de abundancia de dinero y el sentido de la vida. Dos experimentos de laboratorio muestran que los individuos a quienes se les ha activado el concepto de abundancia de dinero reportan que su vida tiene más sentido. Esta relación está completamente mediada por la autoestima. El tercer capítulo, dedicado a los rituales de consumo, explora el efecto que compartir un ritual de consumo tiene en la atracción interpersonal. Dos experimentos de laboratorio muestran que la gente que sigue un ritual de consumo evalúa a otros que también lo siguen más positivamente. Este efecto está parcialmente mediado por los sentimientos de orgullo, y moderado por el hecho de si la otra persona disfruta o no el producto asociado al ritual.
Programa de doctorat en Economia, Finances i Empresa

وصف الملف: application/pdf

الوصول الحر: http://hdl.handle.net/10803/397800Test

المؤلفون: La Duc Viet, Phan Thi Tra My, Nguyen Tuan Ngoc

المصدر: Forces in Mechanics, Vol 15, Iss , Pp 100272- (2024)

مصطلحات موضوعية: Velocity feedback, Skyhook, Active isolation, Analytical optimization, Repeated poles, Mechanics of engineering. Applied mechanics, TA349-359, Technology

الوصف: Vibration isolation is a crucial technology in precision manufacturing. With the rapid development of smart sensors, smart actuators, and microprocessors, active vibration isolation has emerged as a viable approach to improve the performance of manufacturing equipment. In integrated skyhook active vibration isolation, the cut-off frequency limits the controller gain. Base on the repeated poles technique, this paper reveals the simple analytical forms of the optimal cut-off frequency and controller gain of the integrated skyhook active isolation. The analytical formula is useful in the design of active isolation. Numerical calculations are performed to show the good performance of the optimal design. An experiment is carried out to show the existence of the optimal controller gain.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2666359724000180Test; https://doaj.org/toc/2666-3597Test

الوصول الحر: https://doaj.org/article/a8e6f7b1012f465a951b6c6498edc1d3Test

المؤلفون: Dapeng Wei, Bilong Liu, Ludi Kang

المصدر: Acoustics, Vol 5, Iss 2, Pp 414-428 (2023)

مصطلحات موضوعية: velocity feedback, turbulent boundary layer, curved plate, Physics, QC1-999

الوصف: The control of decentralized velocity feedback on curved aircraft plates under turbulent boundary layer excitations is numerically investigated in this paper. Sixteen active control units are set on the plate to reduce the vibration and sound radiation of the plate. The computational results from the two methods are compared to verify the accuracy of the numerical model. The plate kinetic energy and the radiated sound power under turbulent boundary layer and control unit excitations are analyzed. The influences of control unit distribution, plate thickness and curvature on radiated sound are discussed. Unlike a flat plate, the control of the lower-order high radiation modes of a curved plate under TBL excitations is critical since these modes predominate the sound radiations. The control of these modes, however, is sensitive to the ratio of the stiffness associated with the membrane tensions to the stiffness associated with the bending forces. This ratio implies that the plate curvature and the thickness play an important role in the control effect. When the plate is thinner and the radius is smaller, the control is less effective.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2624-599X/5/2/24Test; https://doaj.org/toc/2624-599XTest

الوصول الحر: https://doaj.org/article/6805bf0b2eeb4e1a9b70e3339b5fd3fcTest

المؤلفون: Aleksander Kras, Paolo Gardonio

المصدر: Bulletin of the Polish Academy of Sciences: Technical Sciences, Vol 71, Iss 3 (2023)

مصطلحات موضوعية: inerter, proof mass actuator, velocity feedback, Technology, Technology (General), T1-995

الوصف: This paper presents the experimental results of a new proof mass actuator for the implementation of velocity feedback control loops to reduce the flexural vibration of a thin plate structure. Classical proof mass actuators are formed by coil–magnet linear motors. These actuators can generate constant force at frequencies above the fundamental resonance frequency of the spring–magnet system, which can be used to efficiently implement point velocity feedback control loops. However, the dynamics of the spring–magnet system limit the stability and control performance of the loops when the actuators are exposed to shocks. The proof mass actuator investigated in this paper includes an additional flywheel element that improves the stability of the velocity feedback loop both by increasing the feedback gain margin and by reducing the fundamental resonance frequency of the actuator. This paper is focused on the stability and control performance of decentralized velocity feedback control loops.

وصف الملف: electronic resource

العلاقة: https://journals.pan.pl/Content/126528/PDF/BPASTS_2023_71_3_3348.pdfTest; https://doaj.org/toc/2300-1917Test

الوصول الحر: https://doaj.org/article/7a8de77b1c2f4426be03fcb67091da96Test

المؤلفون: H.S. Bauomy

المصدر: Alexandria Engineering Journal, Vol 61, Iss 2, Pp 1779-1801 (2022)

مصطلحات موضوعية: Functionally graded shells, Nonlinear proportional derivative, Nonlinear cubic velocity feedback, Primary resonance, Perturbation, Stability, Engineering (General). Civil engineering (General), TA1-2040

الوصف: This paper presents a new active controller technique effect of functionally graded (FG) cylindrical shell structure model within joint harmonic and parametric excitations. The new active controller involves Nonlinear Proportional-Derivative (NPD) plus Negative Cubic Velocity Feedback (NCVF) as a new nonlinear control method (NPDCVF). The motivation of this study is the well-known observation that NPDCVF control method can offer a means to improve the performance of plant systems. The coupled nonlinear differential equations with two modes have been derived applying the von Kármán nonlinear theory, Galerkin’s process, and the static condensation technique. Static condensation is the process of decreasing the number of free displacements or degrees of freedom. We have added other three different controller methods over the structure to select the best controller. The three applied controller methods to the considered structure are: Integral Resonant Control (IRC), Positive Position Feedback (PPF), and Nonlinear Integral Positive Position Feedback (NIPPF) which are applied to the considered structure. We establish that the best one for dipping the high vibration amplitudes is the NPDCVF as a new controller. The perturbation technique is useful to solve the present model including quadratic and cubic nonlinearities subjected to mixed harmonic and parametric forces within the simultaneous primary resonance case (Ω=ω1,Ω=ω2) as the worst resonance case of the system. All numerical outcomes have been completed with the help of MATLAB Ra 18.0 program software over the investigated model. The obtained results have proved that this new controller is excellent for improving the structure by reducing the risky vibrations caused during primary resonances. Frequency response equations have helped in observing the stability examination of the obtained numerical solutions. The actions of several factors performed on the controlled model have been examined and described. Some comparisons have also been prepared with the available recent published papers of a similar model.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S1110016821004257Test; https://doaj.org/toc/1110-0168Test

الوصول الحر: https://doaj.org/article/5efdf36f7e8a4cc8823d1f7080e84863Test

المؤلفون: Kras A., Gardonio P.

المساهمون: Kras, A., Gardonio, P.

مصطلحات موضوعية: inerter, proof mass actuator, velocity feedback

الوصف: This paper presents the experimental results of a new proof mass actuator for the implementation of velocity feedback control loops to reduce the flexural vibration of a thin plate structure. Classical proof mass actuators are formed by coil–magnet linear motors. These actuators can generate constant force at frequencies above the fundamental resonance frequency of the spring–magnet system, which can be used to efficiently implement point velocity feedback control loops. However, the dynamics of the spring–magnet system limit the stability and control performance of the loops when the actuators are exposed to shocks. The proof mass actuator investigated in this paper includes an additional flywheel element that improves the stability of the velocity feedback loop both by increasing the feedback gain margin and by reducing the fundamental resonance frequency of the actuator. This paper is focused on the stability and control performance of decentralized velocity feedback control loops.

العلاقة: info:eu-repo/semantics/altIdentifier/wos/WOS:001018990700001; volume:71; issue:3; firstpage:e144605; journal:BULLETIN OF THE POLISH ACADEMY OF SCIENCES. TECHNICAL SCIENCES; https://hdl.handle.net/11390/1260045Test; info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85166617032

الإتاحة: https://doi.org/10.24425/bpasts.2023.144605Test
https://hdl.handle.net/11390/1260045Test

المؤلفون: Zongwei Chen, Zheng Gong, Liwen Pan, Xiuli Zhang

مصطلحات موضوعية: Biochemistry, Medicine, Sociology, Science Policy, Space Science, Biological Sciences not elsewhere classified, Mathematical Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, predicting 1rm using, predicting 1rm compared, velocity measurement device, systematic review aimed, 1rm determination method, div >< p, point method needs, potential influence factors, point method, predict 1rm, reliable method, direct method, velocity variable, velocity feedback, review indicated, full review, three studies, sportdiscus databases, resistance training, p <, outcome measures, offer directions

الوصف: This systematic review aimed to evaluate the reliability and validity of the two-point method in predicting 1RM compared to the direct method, as well as analyze the factors influencing its accuracy. A comprehensive search of PubMed, Web of Science, Scopus, and SPORTDiscus databases was conducted. Out of the 88 initially identified studies, 16 were selected for full review, and their outcome measures were analyzed. The findings of this review indicated that the two-point method slightly overestimated 1RM (effect size = 0.203 [95%CI: 0.132, 0.275]; P < 0.001); It showed that test-retest reliability was excellent as long as the test loads were chosen reasonably (Large difference between two test loads). However, the reliability of the two-point method needs to be further verified because only three studies have tested its reliability. Factors such as exercise selection, velocity measurement device, and selection of test loads were found to influence the accuracy of predicting 1RM using the two-point method. Additionally, the choice of velocity variable, 1RM determination method, velocity feedback, and state of fatigue were identified as potential influence factors. These results provide valuable insights for practitioners in resistance training and offer directions for future research on the two-point method.

العلاقة: https://figshare.com/articles/journal_contribution/S1_File_-/24593579Test

الإتاحة: https://doi.org/10.1371/journal.pone.0294509.s003Test
https://figshare.com/articles/journal_contribution/S1_File_-/24593579Test

المؤلفون: Zongwei Chen, Zheng Gong, Liwen Pan, Xiuli Zhang

مصطلحات موضوعية: Biochemistry, Medicine, Sociology, Science Policy, Space Science, Biological Sciences not elsewhere classified, Mathematical Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, predicting 1rm using, predicting 1rm compared, velocity measurement device, systematic review aimed, 1rm determination method, div >< p, point method needs, potential influence factors, point method, predict 1rm, reliable method, direct method, velocity variable, velocity feedback, review indicated, full review, three studies, sportdiscus databases, resistance training, p <, outcome measures, offer directions

الوصف: This systematic review aimed to evaluate the reliability and validity of the two-point method in predicting 1RM compared to the direct method, as well as analyze the factors influencing its accuracy. A comprehensive search of PubMed, Web of Science, Scopus, and SPORTDiscus databases was conducted. Out of the 88 initially identified studies, 16 were selected for full review, and their outcome measures were analyzed. The findings of this review indicated that the two-point method slightly overestimated 1RM (effect size = 0.203 [95%CI: 0.132, 0.275]; P < 0.001); It showed that test-retest reliability was excellent as long as the test loads were chosen reasonably (Large difference between two test loads). However, the reliability of the two-point method needs to be further verified because only three studies have tested its reliability. Factors such as exercise selection, velocity measurement device, and selection of test loads were found to influence the accuracy of predicting 1RM using the two-point method. Additionally, the choice of velocity variable, 1RM determination method, velocity feedback, and state of fatigue were identified as potential influence factors. These results provide valuable insights for practitioners in resistance training and offer directions for future research on the two-point method.

العلاقة: https://figshare.com/articles/journal_contribution/S1_Checklist_-/24593573Test

الإتاحة: https://doi.org/10.1371/journal.pone.0294509.s001Test
https://figshare.com/articles/journal_contribution/S1_Checklist_-/24593573Test

المؤلفون: X. L. Yu, X. H. Zhang, J. F. Wang

المصدر: Frontiers in Materials, Vol 9 (2022)

مصطلحات موضوعية: first-order shear deformation theory, Hamilton’s principle, velocity feedback control, functionally graded materials, active vibration control, Technology

الوصف: Piezoelectric materials possess excellent electromechanical coupling characteristics, which are functional and suitable in structural vibration control. This study investigates the active control of free and forced vibration for piezoelectric-integrated functionally graded carbon nanotube reinforced composite (FG-CNTRC) plate using the finite element method (FEM). Based on the first-order shear deformation theory (FSDT), the governing equations of the motion of a piezoelectric-integrated FG-CNTRC plate are derived by Hamilton’s principle. The convergence and accuracy of the numerical method is verified through the results of natural frequencies. The influences of CNT volume fraction, CNT distribution type, piezoelectric layer thickness-to-plate thickness ratio, and boundary condition on the natural frequencies are investigated. A constant gain velocity feedback algorithm is used to achieve the dynamic response control of the piezoelectric-integrated FG-CNTRC plate. In addition, the effects of dynamic load, feedback control gain, and boundary condition on the dynamic response of the plate are studied. Numerical results indicate that active control is promising for practical applications in civil and mechanical engineering.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fmats.2022.861388/fullTest; https://doaj.org/toc/2296-8016Test

الوصول الحر: https://doaj.org/article/444ea3ea08d04f09b75fdfdee9de242dTest

المؤلفون: Kesong Chen, Haochen Zhang

المصدر: Sensors; Volume 22; Issue 20; Pages: 7798

مصطلحات موضوعية: teleoperation system, adaptive control, position tracking, velocity feedback filter, time-varying delay

الوصف: The performances of position synchronization and force interaction of the teleoperation system provide a safe and efficient way for operators to perform tasks in remote, hazardous environments. In practice, however, communication delays and dynamic uncertainties can impair the performance of position synchronization controls. Under the above factors, it is necessary to study and design appropriate bilateral control methods to achieve stable and effective position synchronization control. In this paper, a new adaptive control architecture based on velocity feedback filter and radial basis function neural network is proposed. In the proposed control scheme, only the position signal is transmitted during the communication process, and the speed feedback filter and compensation method are designed and adopted to avoid the use of acceleration signals. In addition, a new auxiliary variable with a tracking error integral term is used to reduce the steady-state error of position tracking under nonzero external environmental forces. Using the Lyapunov–Krasovskii method, the stability of closed-loop remote operating systems is demonstrated. In the simulation and experiment sections, the algorithm was verified separately and compared with other algorithms. The results of a master–slave robot system verify the tracking performance of our proposed control scheme.

وصف الملف: application/pdf

العلاقة: Physical Sensors; https://dx.doi.org/10.3390/s22207798Test

الإتاحة: https://doi.org/10.3390/s22207798Test