In comparison to conventional cruise control, adaptive cruise control (ACC) vehicles are capable of sensing forward traffic and slowing to accommodate as necessary. When no forward vehicles are present, ACC function is the same as conventional cruise control. However, with ACC, when a slower vehicle is detected, the ACC system will decelerate and follow at a selected time-based distance. While slowing to follow, the driver will experience a system-controlled deceleration of the ACC vehicle. An experiment was conducted to evaluate driver preferences for the distance at which the primary deceleration occurs and the level of deceleration that is obtained. Driver intervention was required in one trial and driver response behavior was measured. Ten men and ten women in two age groups evaluated the decelerations from a cruise speed of 70mph to a following speed of 55mph behind a confederate lead vehicle on the highway. Evaluations can be made using four scales: Good vs. Bad, Comfortable vs. Uncomfortable, Jerky vs. Smooth, and Early vs. Late. Decelerations of approximately 0.06g which occur approximately 200ft to 250ft behind the lead vehicle were most preferred. Prior to intervention, foot position ranged from a point directly below the brake pedal to 16.4in from the brake pedal. Foot motion began between 21.12s time-to-collision (TTC) and 3.97s TTC. Eighty percent of the participants paused to "cover" the brake before final motion to activate the brake. The older age group intervened (braked) later than the younger age group. Driver braking after intervention ranged from 0.16g to 0.32g. / Master of Science

O principal objetivo deste trabalho é, adotado uma abordagem centrada na simulação numérica, entender a desaceleração a laser de um feixe atômico por meio da conhecida técnica de ajuste Zeeman. Nossos cálculos numéricos são capazes de reproduzir as características fundamentais dos resultados experimentais já obtidos. Também apresentamos um modelo analítico simples incorporando as idéias básicas contidas nas hipóteses utilizadas nas simulações e mostrando que estas idéias são consistentes com as conclusões numéricas e experimentais. Isto demonstra que os aspectos essenciais do processo desacelerador são bem compreendidos. / The main purpose of this work is, adopting a numerical simulation approach, to understand the laser deceleration of an atomic beam by means 0f the kown Zeeman tuning technique. Our numerical calculations are able to reproduce the fundamental features of the experimental results already obtained. We also present a simple analytical model incorporating the basic ideas contained in the hypotheses used in the simulations, and show that these ideas are consistent with the numerical and experimental conclusions. This demonstrates that the essential aspects 0f the deceleration process are well comprehended.

Neste trabalho pela primeira vez, desaceleramos um feixe de Cs pela Técnica de Sintonia Zeeman. Usamos um laser de diodo contrapropagante ao feixe atômico. Essa técnica se baseia na utilização de um campo magnético de perfil espacial parabólico para compensar o efeito Doppler e manter o átomo ressonante com o laser durante o processo de desaceleração. Conseguimos reduzir a velocidade dos átomos até C 940cm/s. Para medir essa velocidade usamos uma técnica simples, diferente da usual, que utiliza um feixe de prova. Com o nosso magneto, não foi possível desacelerar átomos com velocidade acima de 12000 cm/s. O limite de campo magnético em que tivemos que trabalhar corresponde à campo fraco, para o estado fundamental do Cs. Esse fato acarreta um aumento na probabilidade de ocorrerem transições erradas. Observamos a presença de um intervalo de \"detuning\" útil, fora do qual não conseguimos desacelerar. Esse intervalo também está relacionado com o limite máximo de velocidades para que haja desaceleração. Chegamos a esse intervalo através de simulações feitas para encontrar os parâmetros necessários à desaceleração. Os resultados obtidos experimentalmente estão de acordo com o que foi previsto pela simulação. Paralelamente à desaceleração de CS, preparamos os lasers de diodo e reduzimos sua largura de linha. Entretanto não usamos o laser estreito para a desaceleração. A fim de trabalharmos com espectroscopia de alta resolução reduzimos a largura de linha do laser a semicondutor fazendo um acoplamento da cavidade laser com uma cavidade, Fabry-Pérot, externa. Conseguimos estreitar a largura de linha até 500KHz. Esse resultado nos possibilitará investigar as linhas do Cs, aprisionado em um \"trap\" magnético-óptico, experimento este que já está em andamento em nosso laboratório / In this work for the first time, slow a beam of Cs by the Zeeman tuning technique. We use a laser diode contrapropagante the atomic beam. This technique is based on the use of a magnetic field of parabolic spatial profile to compensate for the Doppler effect and keep the atoms resonant with the laser during the downturn. We reduce the speed of C atoms to 940cm / s. To measure this speed we use a simple technique, different from the usual, which uses a beam of evidence. With our magnet, could not slow down atoms with speeds up to 12,000 cm / s. The limit of magnetic field we had to work corresponds to the weak field for the ground state of Cs. This fact implies an increase in the probability of transitions wrong. We observed a range of \"detuning\" useful, out of which we cannot slow down. This range is also related to the maximum speed for there to be slowing. We arrived in this range through simulations to find the parameters needed for deceleration. The results obtained experimentally are in agreement with what was predicted by the simulation. Parallel to the slowdown of CS, we prepared the diode lasers and reduced its line width. However do not use the laser close to the slowdown. In order to work with high-resolution spectroscopy reduced the line width of the semiconductor laser causing a coupling of the laser cavity with a cavity, Fabry-Pérot, external. We narrow the line width up to 500KHz. This result will enable us to investigate the lines of Cs, trapped in a \"trap\" magneto-optical experiment that is already underway in our laboratory

The BOSS symbology for rotorcraft is specifically designed to provide the pilot with the necessary information and guidance to safely land in brownout environments. From the last BOSS study, issues were brought forth regarding the longitudinal velocity algorithm, which sets up a deceleration profile and commands the forward speed of the aircraft throughout the approach. Pilots commented that the algorithm lead the aircraft to be too slow for too long, effectively prolonging the brownout. Thus the purpose of this study was to investigate new algorithms to enable a faster approach with less time spent in brownout. The previous deceleration algorithm was also not robust in its ability to provide consistent guidance at variable starting distances and starting velocities. Therefore a new algorithm was developed capable of providing more consistent guidance from various starting positions and velocities. Additionally, through manipulation of its parameters, it was found possible to reduce the amount of time spent at low speeds in the approach. Four algorithms were subsequently developed with varying levels of aggressiveness. Eight highly skilled pilots participated in a simulation study using a generic fixed-base simulator with a high-fidelity rotorcraft H-60 model. Results found that as the aggressiveness of the algorithm increased, the time spent at low speeds and in brownout significantly decreased. Concurrently the pitch of the aircraft (and resulting deceleration) significantly increased, though the pitch values were within reasonable limits for IMC flight according to previous literature. One of the new algorithms was found to significantly reduce the amount of time spent at low speeds by 24% and also received the highest preference ranking and the highest comfort ratings.

Neste trabalho pela primeira vez, desaceleramos um feixe de Cs pela Técnica de Sintonia Zeeman. Usamos um laser de diodo contrapropagante ao feixe atômico. Essa técnica se baseia na utilização de um campo magnético de perfil espacial parabólico para compensar o efeito Doppler e manter o átomo ressonante com o laser durante o processo de desaceleração. Conseguimos reduzir a velocidade dos átomos até C 940cm/s. Para medir essa velocidade usamos uma técnica simples, diferente da usual, que utiliza um feixe de prova. Com o nosso magneto, não foi possível desacelerar átomos com velocidade acima de 12000 cm/s. O limite de campo magnético em que tivemos que trabalhar corresponde à campo fraco, para o estado fundamental do Cs. Esse fato acarreta um aumento na probabilidade de ocorrerem transições erradas. Observamos a presença de um intervalo de \"detuning\" útil, fora do qual não conseguimos desacelerar. Esse intervalo também está relacionado com o limite máximo de velocidades para que haja desaceleração. Chegamos a esse intervalo através de simulações feitas para encontrar os parâmetros necessários à desaceleração. Os resultados obtidos experimentalmente estão de acordo com o que foi previsto pela simulação. Paralelamente à desaceleração de CS, preparamos os lasers de diodo e reduzimos sua largura de linha. Entretanto não usamos o laser estreito para a desaceleração. A fim de trabalharmos com espectroscopia de alta resolução reduzimos a largura de linha do laser a semicondutor fazendo um acoplamento da cavidade laser com uma cavidade, Fabry-Pérot, externa. Conseguimos estreitar a largura de linha até 500KHz. Esse resultado nos possibilitará investigar as linhas do Cs, aprisionado em um \"trap\" magnético-óptico, experimento este que já está em andamento em nosso laboratório / In this work for the first time, slow a beam of Cs by the Zeeman tuning technique. We use a laser diode contrapropagante the atomic beam. This technique is based on the use of a magnetic field of parabolic spatial profile to compensate for the Doppler effect and keep the atoms resonant with the laser during the downturn. We reduce the speed of C atoms to 940cm / s. To measure this speed we use a simple technique, different from the usual, which uses a beam of evidence. With our magnet, could not slow down atoms with speeds up to 12,000 cm / s. The limit of magnetic field we had to work corresponds to the weak field for the ground state of Cs. This fact implies an increase in the probability of transitions wrong. We observed a range of \"detuning\" useful, out of which we cannot slow down. This range is also related to the maximum speed for there to be slowing. We arrived in this range through simulations to find the parameters needed for deceleration. The results obtained experimentally are in agreement with what was predicted by the simulation. Parallel to the slowdown of CS, we prepared the diode lasers and reduced its line width. However do not use the laser close to the slowdown. In order to work with high-resolution spectroscopy reduced the line width of the semiconductor laser causing a coupling of the laser cavity with a cavity, Fabry-Pérot, external. We narrow the line width up to 500KHz. This result will enable us to investigate the lines of Cs, trapped in a \"trap\" magneto-optical experiment that is already underway in our laboratory

O principal objetivo deste trabalho é, adotado uma abordagem centrada na simulação numérica, entender a desaceleração a laser de um feixe atômico por meio da conhecida técnica de ajuste Zeeman. Nossos cálculos numéricos são capazes de reproduzir as características fundamentais dos resultados experimentais já obtidos. Também apresentamos um modelo analítico simples incorporando as idéias básicas contidas nas hipóteses utilizadas nas simulações e mostrando que estas idéias são consistentes com as conclusões numéricas e experimentais. Isto demonstra que os aspectos essenciais do processo desacelerador são bem compreendidos. / The main purpose of this work is, adopting a numerical simulation approach, to understand the laser deceleration of an atomic beam by means 0f the kown Zeeman tuning technique. Our numerical calculations are able to reproduce the fundamental features of the experimental results already obtained. We also present a simple analytical model incorporating the basic ideas contained in the hypotheses used in the simulations, and show that these ideas are consistent with the numerical and experimental conclusions. This demonstrates that the essential aspects 0f the deceleration process are well comprehended.

This diploma thesis called Motorcycle Race Dynamics captures the development and development of motorcycles, a description of types, design elements and the techniques of riding a motorcycle. However, the aim of this work is to organize, perform and evaluate the measurement of braking deceleration and the crossing of motorcycles. Before separate data processing, a theoretical methodology for measuring transverse displacement and braking deceleration is proposed. This requires enough motorcycles, experienced riders, two cameras, a measuring instrument and precisely dimensioned lines. The lateral displacement and braking deceleration measurements are then performed and subsequently evaluated. Output of this work include, in addition to videos, an overview of transverse displacement times, or longitudinal deceleration output values gained from braking.

The main aim of this diploma thesis is to deal with the influence of tire properties and parameters of driving dynamics. In the introduction are discussed the driving dynamics of vehicles and the importance of tires and their construction. The second part is devoted to implementation and evaluation of the own experiment. My experiment is to test the braking tire inflation and condition of various different sizes. The conclusion summarizes the importance of proper tire condition.

Thesis advisor: Elizabeth A. Kensinger / Emotion enhances memory longevity and vividness. Perceiving an experience as emotional, as well as the autonomic and functional brain responses involved in initially encoding an emotional experience, have been theorized to “tag” these memories. Tagged memories may then be prioritized for consolidation during sleep. However, direct evidence supporting this theory is sparse. The aim of the present study was to determine which encoding-related indicators of memory tagging interact with post-encoding sleep oscillations to promote emotional memory retention and vividness. To test this, participants incidentally encoded positive, neutral and negative multisensory stimuli during 3T fMRI scanning with concurrent heart rate monitoring. Participants provided emotional intensity ratings after each stimulus presentation. Following a 120-min post-encoding nap opportunity recorded with polysomnography, participants completed a surprise memory test. Memory for emotional and neutral stimuli was equivalent, though emotional stimuli tended to be remembered more vividly. Perceived emotional intensity, but not heart rate deceleration (HRD) magnitude or functional brain activity, was diagnostic of later successful retrieval of emotional, but not neutral stimuli. Higher REM sleep theta power during the nap was associated with a greater emotional intensity (EI) subsequent memory effect (i.e., higher EI for later remembered compared to forgotten stimuli) for positive stimuli, which were also remembered more vividly. Higher NREM spindle density was associated with a greater EI subsequent memory effect for neutral stimuli and lesser EI subsequent memory effect for negative stimuli. Lastly, higher numbers of NREM spindle-slow oscillation coupling events predicted a negative relationship between perceived emotional intensity at encoding and memory vividness for negative stimuli. Taken together, the present findings suggest that subjective, rather than objective, encoding-related arousal responses acted as emotion “tags”. How subjective arousal impacted later memory varied as a function of the memory’s emotion category and REM and NREM-specific oscillations. Future work is needed to clarify the underlying mechanisms for these observed effects. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Psychology.

Driver violations at traffic signals are a major cause of intersection vehicle crashes. The yellow interval is used to inform approaching drivers of an upcoming change in the traffic signal indication from green to red. Current yellow-interval durations are currently calculated to accommodate for dilemma zone protection for passenger cars only. Buses with different vehicle, driver, and occupancy characteristics behave differently at the onset of a yellow indication. The research presented in this thesis characterizes the difference between bus and passenger car driver behavior at the onset of yellow-indication. A revised set of yellow timing procedures are presented to address the requirements for bus dilemma zone protection. A dataset of 864 stop-go records were collected as part of the research effort using a school bus approaching a traffic signal on the Virginia Smart Road facility. The experiment was conducted at an instructed speed limit of 57 km/h (35 mph) approach speed where participant drivers were presented with yellow indications. A total of 36 participating bus drivers were randomly selected from three age groups (under 40 years old, 40 to 64 years old and 65 and above) with equal number of male and female for each age group. Using the data collected as part of this research effort, statistical models were created to model bus driver perception-reaction times (PRTs) and deceleration levels considering driver attributes (age and gender), roadway grade, vehicle approach speed, and time to intersection (TTI) at the onset of the yellow indication. A Monte-Carlo simulation was conducted to develop appropriate yellow indication timings to provide adequate dilemma zone protection for buses. Lookup tables were then developed for different reliability levels to provide practical guidelines for the design of yellow signal timings to accommodate different bus percentages within the traffic stream. The recommended change durations can be integrated within the Vehicle Infrastructure Integration (VII) initiative to provide customizable driver warnings prior to a transition to a red indication. / Master of Science