Esta dissertação descreve o movimento quântico de uma partícula numa barreira de potencial parabólica, condicionalmente este sistema é chamado de oscilador invertido. Determinamos estados quânticos semiclássicos como família de estados coerentes generalizados (ECG), sendo construídos através da adaptação do trabalho de Malkin e Man´ko, determinando-se um operador que seja integral do movimento, parametrizado por algumas constantes e reconhecido como operador de aniquilação, cujos auto-estados tem características dos estados comprimidos. Discutimos suas propriedades e observamos que é possível comparar ECG do oscilador invertido com ECG da partícula livre e oscilador harmônico obtidos na literatura. Também é feito um estudo do movimento puramente quântico (tunelamento) nas barreiras de potenciais do oscilador invertido e oscilador invertido truncado, por meio das soluções estacionárias exatas e aproximadas (JWKB), comparando os resultados obtidos em cada situação. / This dissertation describes the motion of a particle in a quantum potential barrier parabolic, this system is conditionally called inverted oscillator. Determined quantum states semi-classics like family generalized coherent states (GCS), being constructed by adapting work Malkin\'s and Man\'ko, determining an operator who is integral of the motion, parameterized for some constants and recognized as annihilation operator, whose eigenstates have characteristics of squeezed states. We discuss its properties and note that it is possible to compare the GCS of inverted oscillator with GCS the particle free and harmonic oscillator obtained in the literature. Also made a study of the movement purely quantum (tunneling) in the barriers potential inverted oscillator and truncated inverted oscillator by means of exact and approximate stationary solutions (JWKB), comparing the results obtained in each situation.

Self-balancing robots are unique mobile platforms that stay upright on two wheels using a closed-loop control system. They can turn on the spot using differential steering and have compact form factors that limit their required floor space. However they have major limitations keeping them from being used in real world applications: they cannot stand-up on their own, climb stairs, or overcome obstacles. They can fall easily if hit or going onto a slippery surface because they rely on friction for balancing. The first part of this research proposes a novel design to address the above mentioned issues related to stair-climbing, standing-up, and obstacles. A single revolute joint is added to the centre of a four-wheel drive robot onto which an arm is attached, allowing the robot to successfully climb stairs and stand-up on its own from a single motion. A model and simulation of the balancing and stair-climbing process are derived, and compared against experimental results with a custom robot prototype. The second part, a control system for an inverted pendulum equipped with a gyroscopic mechanism, was investigated for integration into self-balancing robots. It improves disturbance rejection during balance, and keeps equilibrium on slippery surfaces. The model of a gyroscope mounted onto an actuated gimbal was derived and simulated. To prove the concept worked, a custom-built platform showed it is possible for a balancing robot to stay upright with zero traction under the wheels.

Antennas in hand-held radios must be compact and unobtrusive. Electrically small and low-profile antennas experience high input reactance, low input resistance, and low radiation efficiency.Further degradation of radiation efficiency occurs in hand-held radios due to size-reduced ground planes, losses within the plastic device casing, and losses due to coupling with the tissue of the user. These factors may also affect the radiation pattern of the antenna. This discussion reports on antenna designs that are well suited for hand-held radios. The design issues are covered for electrically small antennas and the hand-held environment. A review of Microstrip Antenna (MSA) theory, and the theory of the Inverted-L Antenna (ILA), and variations on the ILA including the Inverted-F Antenna (IFA), Planar Inverted-F Antenna (PIFA), and Dual Inverted-F Antenna (DIFA) is included. Two specific antenna designs are presented: the DIFA and the Proximity-Coupled Rectangular Patch MSA. The radiation patterns and input impedance of the DIFA are calculated numerically and measured empirically. The Proximity-Coupled Rectangular Patch Microstrip Antenna is treated numerically. / Master of Science

The idea of the “flipped classroom” is a relatively new concept in education that has become increasingly popular. Instructors who flip their classrooms reverse the roles of school work and homework by recording video lectures for students to watch before coming to class. Students then work on their homework in the classroom while the instructor is present to help them. Very little research has been done on the effectiveness of the flipped classroom to determine if students can perform better on exams by learning in a flipped classroom environment, especially for high school demographics. The purpose of this research is to add to the body of knowledge and help provide data to investigate how well students learn physics content by using the flipped classroom in a high school physics class and identify students' attitudes towards the flipped classroom. Seven periods of Physics with Technology at Lone Peak High School in Highland, UT were used in this study. Three of the classes were randomly assigned to be “flipped” while the other four were taught using what is considered a “traditional” method of instruction of physics, which is based on a guided inquiry method. The pacing and content was matched each day and all classes participated in the same labs, homework, quizzes and tests. The defining difference is the method which the content is covered. The flipped classes watched video lectures at home to learn the majority of the content, then did what is traditionally known as “homework” in class with the teacher present to help. In this study, it was found that there was no statistically or practically significant difference in mean test scores for the first three units in a high school Physics with Technology class. Student responses on a survey also showed very little statistically different in the students' attitudes towards the classroom environment in either instructional method.

Yes / This paper examines the case for an ultrawideband planar inverted-F-L-antenna design intended for use in the lower sub-band. The antenna construction is based on the conventional inverted F, and inverted L as its feed element, and parasitic element, respectively. The optimized antenna size is 30×15×4mm3. The prototype antenna has a good return loss of -10 dB, and a 66.6% impedance bandwidth (2.8 GHz ¿ 5.6 GHz), the gain varies between 3.1 dBi and 4.5 dBi.

In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.

No description available.

Yes / A frequency tunable planar inverted F antenna (PIFA) is presented for use in the following bands: DCS, PCS, and UMTS. Initially, the tuning was achieved by placing a lumped capacitor, with values in the range of 1.5 to 4 pF, along the slot of the radiator. The final tuning circuit uses a varactor diode, and discrete lumped elements are fully integrated with the antenna. The antenna prototype is tunable over from 1850 MHz to 2200 MHz, with an associated volume of 21×13.5×5 mm3, making it suitable for potential integration in a commercial handset or mobile user terminal.

Suspension of the body in the head-down posture (90° below the horizontal) for traction and added resistance to exercise has generated considerable interest in recent years. However, recent investigators of inversion have cautioned individuals not to participate in such activities until further research could be performed on the effects of exercise in the head-down position. The purpose of this investigation was to examine the acute metabolic and hemodynamic responses of men at rest and during exercise in the inverted posture (90° head-down tilt) versus the supine and standing postures. The parameters investigated were oxygen consumption(V̇O₂), heart rate(HR), systolic blood pressure (SBP), and diastolic blood pressure(DBP). Eleven male recreational athletes underwent 6 sessions of postural change. The baseline posture was sitting and the critical positions were supine, standing, and inverted. The subjects were asked to remain in each of these postures for three minutes. In the first 2 sessions, oxygen consumption(V̇O₂), was measured at rest and during 45° hip-f1exion respectively, The V̇O₂ in the inverted posture at rest was found to be 1.7% greater than the V̇O₂ in the standing and the supine postures. V̇O₂ in the inverted posture during exercise was 7% and 36.5% greater than in the supine and standing postures, respective1y. A statistical significance in HR at rest in the standing posture versus the inverted and supine postures was observed. During 45° hip-flexion activity, the HR in the standing posture was found to be significantly faster than the supine posture. The HR in the inverted posture was significantly faster than the supine posture as well. At rest, there was no significant increase in SBP as re1ated to posture. During exercise, the SBP was significant1y greater; at rest in each of the postures. Both postural and exercise factors significantly affected the DBP. The post-hoc analyses showed supine resting DBP was significantly lower than in the other two resting postures. During exercise, the standing BP was significantly greater than the supine and inverted DBP. These data demonstrate: A) V̇O₂ in the supine and inverted postures is significantly greater than in the standing postures. B) a statistically significant increase in HR occurs in the standing posture as compared to the supine and inverted postures; however, it does not appear to be clinically significant, C) with the arms maintained in the anatomical position for all postural changes, the SBP was not significantly affected by the change of posture, but was significantly increased with exercise. D) and DBP in the standing posture was statistically greater than in the other two postures and DBP in the inverted posture was significantly elevated above that found in the supine posture. / Master of Science

There is a need for smaller and more economic transportation systems. Two-wheeled inverted-pendulum machines, such as the Segway, have been proposed to address this need. However, the Segway places the operator on top of a naturally unstable platform that is stabilized by means of a control system. The control stability of the Segway can be severely affected when minor disturbances or unanticipated conditions arise. In this thesis, a dynamic model of a Segway is developed and used in simulations of various conditions that can arise during normal use. The dynamic model of a general two-wheeled inverted pendulum and human rider is presented. Initial estimates of the parameters were calculated or obtained from other references. The results from numerous experiments are presented and used to develop a better understanding of the dynamics of the vehicle. The experimental data was then used to adjust the model parameters to match the dynamics of a real Segway Human Transporter. Finally, the model was used to simulate various failure conditions. The simulations provide a better understanding of how these conditions arise, and help identify which parameters play an important role in their outcome.