Where, when, and how well people park: a phone survey and field measurements

AVM and Low Speed Maneuvers: Human Factors Issues ProjectTwo evaluations were completed to characterize where, how often, and how accurately people normally park. A telephone survey of 30 drivers examined where people park most frequently and the problems drivers have parking. The focus was on executing maneuvers, not the availability of parking. Depending on how the question was asked, approximately 74 to 84 percent of the parking events involved perpendicular parking. Of the 8 parking-related crashes reported by subjects, 6 involved backing, usually with a vehicle traveling down an aisle or backing up from a parking stall. A field survey examined the parking accuracy of 102 vehicles in Ann Arbor, Michigan, a college town. For parallel parking, drivers parked about 4 in from the curb in spaces averaging 24 feet long. For angle parking, distances to the front of the space were bimodal, with some drivers parking about 10 inches from the end of the space and others overlapping by 10 in on average. Overall, drivers parked slightly to the right of center (by 1 inch for parallel parking and 4 inches for perpendicular parking) for 8.5 feet wide spaces. Yaw angles were almost always less than 1 degree for perpendicular and angle parking, but as much as 3 degrees for parallel parking, which is a more difficult task. The data from this experiment provide both a basis for establishing the conditions for parking experiments and baseline data on how well people park without assistance.Nissan Research Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/87990/1/102765.pd

The Magellanic Edges Survey III. Kinematics of the disturbed LMC outskirts

We explore the structural and kinematic properties of the outskirts of the Large Magellanic Cloud (LMC) using data from the Magellanic Edges Survey (MagES) and Gaia EDR3. Even at large galactocentric radii ($8^\circ<R<11^\circ$), we find the north-eastern LMC disk is relatively unperturbed: its kinematics are consistent with a disk of inclination ~$36.5^\circ$ and line-of-nodes position angle ~$145^\circ$ east of north. In contrast, fields at similar radii in the southern and western disk are significantly perturbed from equilibrium, with non-zero radial and vertical velocities, and distances significantly in front of the disk plane implied by our north-eastern fields. We compare our observations to simple dynamical models of the Magellanic/Milky Way system which describe the LMC as a collection of tracer particles within a rigid potential, and the Small Magellanic Cloud (SMC) as a rigid Hernquist potential. A possible SMC crossing of the LMC disk plane ~400 Myr ago, in combination with the LMC's infall to the Milky Way potential, can qualitatively explain many of the perturbations in the outer disk. Additionally, we find the claw-like and arm-like structures south of the LMC have similar metallicities to the outer LMC disk ([Fe/H]~-1), and are likely comprised of perturbed LMC disk material. The claw-like substructure is particularly disturbed, with out-of-plane velocities >60 km s$^{-1}$ and apparent counter-rotation relative to the LMC's disk motion. More detailed N-body models are necessary to elucidate the origin of these southern features, potentially requiring repeated interactions with the SMC prior to ~1 Gyr ago.Comment: Accepted by MNRA

The Magellanic Edges Survey II. Formation of the LMC's northern arm

The highly-substructured outskirts of the Magellanic Clouds provide ideal locations for studying the complex interaction history between both Clouds and the Milky Way (MW). In this paper, we investigate the origin of a >20$^\circ$ long arm-like feature in the northern outskirts of the Large Magellanic Cloud (LMC) using data from the Magellanic Edges Survey (MagES) and Gaia EDR3. We find that the arm has a similar geometry and metallicity to the nearby outer LMC disk, indicating that it is comprised of perturbed disk material. Whilst the azimuthal velocity and velocity dispersions along the arm are consistent with those in the outer LMC, the in-plane radial velocity and out-of-plane vertical velocity are significantly perturbed from equilibrium disk kinematics. We compare these observations to a new suite of dynamical models of the Magellanic/MW system, which describe the LMC as a collection of tracer particles within a rigid potential, and the SMC as a rigid Hernquist potential. Our models indicate the tidal force of the MW during the LMC's infall is likely responsible for the observed increasing out-of-plane velocity along the arm. Our models also suggest close LMC/SMC interactions within the past Gyr, particularly the SMC's pericentric passage ~150 Myr ago and a possible SMC crossing of the LMC disk plane ~400 Myr ago, likely do not perturb stars that today comprise the arm. Historical interactions with the SMC prior to ~1 Gyr ago may be required to explain some of the observed kinematic properties of the arm, in particular its strongly negative in-plane radial velocity.Comment: Accepted by MNRA

Community-Based OT Program Planning: A Virtual Level II Fieldwork Program Developed in Response to the Global Pandemic

The purpose of this article is to explain how an occupational therapy (OT) program in a university setting developed a virtual Level II community-based fieldwork program in response to the COVID-19 global pandemic. This virtual fieldwork program, guided by the PRECEDE-PROCEED Planning Model (PPM), was designed to help keep students on track with their academic goals while providing them with experiential learning that would increase their confidence in OT program planning and promote their professional development. Outcome measures for this study consisted of a pre-and post-fieldwork survey that asked participants to rank their self-perceived confidence in five distinct areas of community-based OT program development. Some portions of Section III in the Student’s Evaluation of the Fieldwork Experience (SEFWE) form were also used to examine students’ feedback after participating in this virtual fieldwork program. Retrospective data analysis of pre-post survey results showed improvements in students’ perceived confidence with certain aspects of OT program development in community settings. Within the core function of program development, occupation-based approaches to community-based programs can be used to inform, educate, and empower people and populations about important health issues while simultaneously offering students rich opportunities for professional development and identity. Dissemination of this information can be helpful to other OT professionals who are developing alternate fieldwork programs in response to the pandemic and beyond

Pressure-dependent EPANET extension

In water distribution systems (WDSs), the available flow at a demand node is dependent on the pressure at that node. When a network is lacking in pressure, not all consumer demands will be met in full. In this context, the assumption that all demands are fully satisfied regardless of the pressure in the system becomes unreasonable and represents the main limitation of the conventional demand driven analysis (DDA) approach to WDS modelling. A realistic depiction of the network performance can only be attained by considering demands to be pressure dependent. This paper presents an extension of the renowned DDA based hydraulic simulator EPANET 2 to incorporate pressure-dependent demands. This extension is termed “EPANET-PDX” (pressure-dependent extension) herein. The utilization of a continuous nodal pressure-flow function coupled with a line search and backtracking procedure greatly enhance the algorithm’s convergence rate and robustness. Simulations of real life networks consisting of multiple sources, pipes, valves and pumps were successfully executed and results are presented herein. Excellent modelling performance was achieved for analysing both normal and pressure deficient conditions of the WDSs. Detailed computational efficiency results of EPANET-PDX with reference to EPANET 2 are included as well

The Magellanic Edges Survey I. Description and First Results

We present an overview of, and first science results from, the Magellanic Edges Survey (MagES), an ongoing spectroscopic survey mapping the kinematics of red clump and red giant branch stars in the highly substructured periphery of the Magellanic Clouds. In conjunction with Gaia astrometry, MagES yields a sample of ~7000 stars with individual 3D velocities that probes larger galactocentric radii than most previous studies. We outline our target selection, observation strategy, data reduction and analysis procedures, and present results for two fields in the northern outskirts ($>10^{\circ}$ on-sky from the centre) of the Large Magellanic Cloud (LMC). One field, located in the vicinity of an arm-like overdensity, displays apparent signatures of perturbation away from an equilibrium disk model. This includes a large radial velocity dispersion in the LMC disk plane, and an asymmetric line-of-sight velocity distribution indicative of motions vertically out of the disk plane for some stars. The second field reveals 3D kinematics consistent with an equilibrium disk, and yields $V_{\text{circ}}=87.7\pm8.0$km s$^{-1}$ at a radial distance of ~10.5kpc from the LMC centre. This leads to an enclosed mass estimate for the LMC at this radius of $(1.8\pm0.3)\times10^{10}\text{M}_{\odot}$.Comment: 23 pages, 10 figures. Accepted by MNRA

Multimodal freight transportation: sustainability challenges

Due to globalization in trade, the development of multimodal cargo shipments and the related transport needs have created a range of challenges. Interestingly, sustainability of multimodal freight transportation is still subject to minor consideration, on the grounds that economic interests are frequently positioned much higher than social or environmental objectives. This proposed research plan is needed to assess whether and to what extent the multimodal freight system is achieving the results in the sustainability dimensions: economic, social and environmental. Thus, it will carry out a critical appraisal of the multimodal freight transportation sector to provide an up-to-date knowledge on the sustainability challenges and the potential solutions through doctoral research. This paper structured to present a review of existing literature on freight transportation and multimodal freight transport highlighting the sustainability concerns with multimodal freight transport systems. It also highlights the gaps in knowledge with a justification on the need to address these gaps for the system to function optimally. It also covers the methodology that would be applied and the sources of data that would be reviewed to ensure the aim and objectives are clearly addressed. The paper concludes by discussing the significance of the expected findings in the light of sustainability in multimodal freight transport to the academia, policy makers and the freight transportation industry

S5S^5: Probing the Milky Way and Magellanic Clouds potentials with the 6-D map of the Orphan-Chenab stream

We present a 6-D map of the Orphan-Chenab (OC) stream by combining the data from 5 years of Southern Stellar Stream Spectroscopic Survey $S^5$ observations with Gaia EDR3 data. We reconstruct the proper motion, radial velocity, distance and on-sky track of stream stars with spline models and extract the stellar density along the stream. The stream has a total luminosity of $M_V=-8.2$ and an average metallicity of $[Fe/H]=-1.9$, similar to classical MW satellites like Draco. The stream shows drastic changes in its physical width varying from 200 pc to 1 kpc, a constant line of sight velocity dispersion of 5 km/s, but an increase in the velocity dispersion along the stream near pericenter to $\sim$ 10 km/s. Despite the large apparent variation in the stellar number density along the stream, the flow rate of stars along the stream is remarkably constant. We model the 6-D stream track by a Lagrange-point stripping method with a flexible MW potential in the presence of a moving extended LMC potential. This allows us to constrain the mass profile of the MW within the distance range 15.6 < r < 55.5 kpc, with the best measured enclosed mass of $(2.85\pm 0.1)\times10^{11}\,M_\odot$ within 32.4 kpc. With the OC stream's closest approach distance to the LMC of $\sim 21$ kpc, our stream measurements are highly sensitive to the LMC mass profile with the most precise measurement of the LMC's enclosed mass being at 32.8 kpc with $M=(7.02\pm 0.9)\times10^{10}\, {M}_\odot$. We confidently detect that the LMC DM halo extends to at least 53 kpc. The fitting of the OC stream allows us to constrain the past LMC trajectory and the degree of dynamical friction it experienced. We demonstrate that the stars on the OC stream show large energy and angular momentum spreads caused by the LMC perturbation and revealing the limitations of orbital invariants for substructure identification in the MW halo.Comment: submitted to MNRAS; comments welcome; data released with the paper is available on Zenodo https://zenodo.org/record/722265