Stereo visual simultaneous localisation and mapping for an outdoor wheeled robot: a front-end study

For many mobile robotic systems, navigating an environment is a crucial step in autonomy and Visual Simultaneous Localisation and Mapping (vSLAM) has seen increased effective usage in this capacity. However, vSLAM is strongly dependent on the context in which it is applied, often using heuristic and special cases to provide efficiency and robustness. It is thus crucial to identify the important parameters and factors regarding a particular context as this heavily influences the necessary algorithms, processes, and hardware required for the best results. In this body of work, a generic front-end stereo vSLAM pipeline is tested in the context of a small-scale outdoor wheeled robot that occupies less than 1m3 of volume. The scale of the vehicle constrained the available processing power, Field Of View (FOV), actuation systems, and image distortions present. A dataset was collected with a custom platform that consisted of a Point Grey Bumblebee (Discontinued) stereo camera and Nvidia Jetson TK1 processor. A stereo front-end feature tracking framework was described and evaluated both in simulation and experimentally where appropriate. It was found that scale adversely affected lighting conditions, FOV, baseline, and processing power available, all crucial factors to improve upon. The stereo constraint was effective for robustness criteria, but ineffective in terms of processing power and metric reconstruction. An overall absolute odometer error of 0.25-3m was produced on the dataset but was unable to run in real-time

A Comprehensive Analysis Of Clouds, Radiation, And Precipitation In The North Pacific Itcz In The NASA GISS Modele GCM And Satellite Observations

Global circulation/climate models (GCMs) remain as an invaluable tool to predict future potential climate change. To best advise policy makers, assessing and increasing the accuracy of climate models is paramount. The treatment of clouds, radiation and precipitation in climate models and their associated feedbacks have long been one of the largest sources of uncertainty in predicting any potential future climate changes. Three versions of the NASA GISS ModelE GCM (the frozen CMIP5 version [C5], a post-CMIP5 version with modifications to cumulus and boundary layer turbulence parameterizations [P5], and the most recent version of the GCM which builds on the post-CMIP5 version with further modifications to convective cloud ice and cold pool parameterizations [E5]) have been compared with various satellite observations to analyze how recent modifications to the GCM has impacted cloud, radiation, and precipitation properties. In addition to global comparisons, two areas are showcased in regional analyses: the Eastern Pacific Northern ITCZ (EP-ITCZ), and Indonesia and the Western Pacific (INDO-WP). Changes to the cumulus and boundary layer turbulence parameterizations in the P5 version of the GCM have improved cloud and radiation estimations in areas of descending motion, such as the Southern Mid-Latitudes. Ice particle size and fall speed modifications in the E5 version of the GCM have decreased ice cloud water contents and cloud fractions globally while increasing precipitable water vapor in the model. Comparisons of IWC profiles show that the GCM simulated IWCs increase with height and peak in the upper portions of the atmosphere, while 2C-ICE observations peak in the lower levels of the atmosphere and decrease with height, effectively opposite of each other. Profiles of CF peak at lower heights in the E5 simulation, which will potentially increase outgoing longwave radiation due to higher cloud top temperatures, which will counterbalance the decrease in reflected shortwave associated with lower CFs and the thinner optical depths associated with decreased IWC and LWC in the E5 simulation. Vertical motion within the newest E5 simulation is greatly weakened over the EP-ITCZ region, potentially due to atmospheric loading from enhanced ice particle fall speeds. Comparatively, E5 simulated upward motion in the INDO-WP is stronger than its predecessors. Changes in the E5 simulation have resulted in stronger/weaker upward motion over the ocean/land in the INDO-WP region in comparison with both the C5 and P5 predecessors. Multimodel precipitation analysis shows that most of the GCMs tend to produce a wider ITCZ with stronger precipitation compared to GPCP and TRMM precipitation products. E5-simulated precipitation decreases and shifts Southward over the Easter Pacific ITCZ, which warrants further investigation into meridional heat transport and radiation fields

Assessment Of Nasa Giss Cmip5 Modele Simulated Clouds And Toa Radiation Budgets Using Satellite Observations Over The Southern Mid-Latitudes

Past, current, and future climates have been simulated by the National Aeronautics and Space Administration (NASA) Goddard Institute for Space Studies (GISS) ModelE Global Circulation Model (GCM) and summarized by the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC, AR4). New simulations from the updated CMIP5 version of the NASA GISS ModelE GCM were recently released to the public community during the summer of 2011 and will be included in the upcoming IPCC AR5 ensemble of simulations. Due to the recent nature of these simulations, they have not yet been extensively validated against observations. To assess the NASA GISS-E2-R GCM, model simulated clouds and cloud properties are compared to observational cloud properties derived from the Clouds and Earth\u27s Radiant Energy System (CERES) project using MODerate Resolution Imaging Spectroradiometer (MODIS) data for the period of March 2000 through December 2005. Over the 6-year period, the global average modeled cloud fractions are within 1% of observations. However, further study however shows large regional biases between the GCM simulations and CERES-MODIS observations. The southern mid-latitudes (SML) were chosen as a focus region due to model errors across multiple GCMs within the recent phase 5 of the Coupled Model Intercomparison Project (CMIP5). Over the SML, the GISS GCM undersimulates total cloud fraction over 20%, but oversimulates total water path by 2 g m-2. Simulated vertical cloud distributions over the SML when compared to both CERES-MODIS and CloudSat/CALIPSO observations show a drastic undersimulation of low level clouds by the GISS GCM, but higher fractions of thicker clouds. To assess the impact of GISS simulated clouds on the TOA radiation budgets, the modeled TOA radiation budgets are compared to CERES EBAF observations. Because modeled low-level cloud fraction is much lower than observed over the SML, modeled reflected shortwave (SW) flux at the TOA is 13 W m-2 lower and outgoing longwave radiation (OLR) is 3 W m-2 higher than observations. Finally, cloud radiative effects (CRE) are calculated and compared with observations to fully assess the impact of clouds on the TOA radiation budgets. The difference in clear-sky reflected SW flux between model and observation is only +4 W m-2 while the SW CRE difference is up to 17 W m-2, indicating that most of the bias in SW CRE results from the all-sky bias between the model and observation. A sizeable negative bias of 10 W m-2 in simulated clear-sky OLR has been found due to a dry bias in calculating observed clear-sky OLR and lack of upper-level water vapor at the 100-mb level in the model. The dry bias impacts LW CRE, with the model undersimulating by 13 W m-2. The net CRE difference is only 5 W m-2 due to the cancellation of SW and LW CRE biases

Establishing the Effect of Ethanol on Listeria Infection

Excessive alcohol consumption is common in the United States, particularly among college campuses. Previous studies have shown that excessive drinking increases the risk of drug dependency, sexual assault and liver damage. Heavy drinking has also proven to impact immune capabilities. Immune cell function and numbers have been shown to be negatively impacted by alcohol treatment. This research project used different cell cultures to model human cells and investigated how exposure to alcohol affects susceptibility to bacterial infection. Listeria monocytogenes, a common foodborne bacterium, was used as a model pathogen. A high alcohol preferring mouse model was also used to examine the complex organismal responses to alcohol consumption prior to infections. These experiments were done in order to better understand the effects of alcohol consumption on the function of the human immune system and to help identify strategies to combat negative consequences associated with excessive drinking

Understanding How Displacement Affects Hiv Prevalence Among Displaced Populations- A Scoping Review

Over the course of the past two decades, the number of people who have been displaced has increased dramatically. With this brings a new set of health challenges for these populations as well as the countries to which these populations are displaced such as HIV/AIDS. There is evidence to show that forced displacement can cause an increase in the HIV prevalence among those displaced. However, there is evidence to suggest the contrary, as well. The aim of this scoping review study is to determine what the existing literature can and cannot tell us about how forced displacement affects HIV prevalence among those displaced. With this better understanding of existing literature, further research can be planned more effectively to fill in existing gaps. A scoping review protocol was developed and two databases, PubMed and Medline, were scanned for articles that met the inclusion criteria. In total, 636 article titles and abstracts were scanned and of these, 85 articles were read in full and 25 were deemed to meet the inclusion criteria. Analysis of the extracted data revealed a potential influence of the HIV prevalence of the country being fled to and the HIV prevalence of the displaced group. If the HIV prevalence of a country or region was high, the HIV prevalence of displaced groups fleeing to these regions were higher. The same trend was seen with HIV low regions and a lower HIV prevalence in displaced groups. The scoping review also showed a lack of proper studies having been done to answer this particular question. There was also a lack of studies of certain regions of the world regarding HIV prevalence among displaced populations such as the Middle East and Central and Southern America. In order to answer this question more effectively, a longitudinal study of a fixed population should be done to determine how forced displacement affects HIV prevalence among those displaced

Links Between Social Support, Thwarted Belongingness, and Suicide Ideation among Lesbian, Gay, and Bisexual College Students

Emerging adults with a lesbian, gay, or bisexual (LGB) identity are at greater risk for engaging in suicide-related behaviors. This disparity highlights a need to elucidate specific risk and protective factors associated with suicide-related behaviors among LGB youth, which could be utilized as targets for suicide prevention efforts in this population. Informed by the interpersonal-psychological theory of suicide, the present study hypothesized that social support would be indirectly associated with decreased suicide ideation via lower thwarted belongingness. A sample of 50 emerging adults (62.0% male, 70.0% Hispanic) who identified as gay, lesbian, bisexual, questioning, or “other” orientation, with a mean age of 20.84 years (SD = 3.30 years), completed self-report assessments. Results indicated that support from both family and the LGB community were associated with lower thwarted belongingness over and above the effects of age, sex, and depressive symptoms. Indirect effects models also indicated that both family and LGB community support were associated with suicide ideation via thwarted belongingness. The results of the present study suggest that family and LGB community support may represent specific targets for reducing thwarted belongingness that could be leveraged in suicide prevention efforts for LGB emerging adults

Letter from the Editors

[Excerpt] We are honored to present the 12th Volume of the Cornell Real Estate Review (CRER), a student edited and managed publication with oversight from faculty in the Baker Program in Real Estate at Cornell University. A continuation of the tradition of thought leadership in real estate, the CRER strives to promote practical learning and to introduce readers to new concepts and practices. As editors, it is our duty to marry scholarly discourse with professional applicability and to create a publication that reflects the values of the Baker Program