111 - Spatial Analysis of Scattered Tree Loss in Livingston County, New York, 1938 to 2021

Scattered-tree agricultural landscapes possess ecological, cultural, and aesthetic value, yet they have seen 20th century decreases worldwide due to various land-use processes. This study analyzes the loss of scattered tree landscapes between 1938 and 2021 in Livingston County, New York State. Located in western New York, Livingston County encompasses the middle Genesee Valley, a noteworthy region since it contained extensive oak savannas purportedly once maintained by Native American (Onöndowa\u27ga:\u27 [Seneca] people) fire use, and contains open-grown landscapes dominated by oaks today. Historical and contemporary aerial photographs and GIS are utilized to classify land use and quantify the change of scattered tree land units. Land use trajectories of scattered tree units are also examined in order to provide insight into the causes of tree loss, which were substantial over the time period. Preliminary results suggest a partial correspondence between historical oak savannas circa 1790 and scattered tree landscapes in 1938, suggesting that oak savannas were partially maintained through Euro-American land-use decisions (e.g. maintaining or modifying oak savannas as pastures)

Perceptions and Predictions with School Climate: Analyzing the Comprehensive School Climate Inventory

Through multiple regression and analysis of variance, data from the Comprehensive School Climate Inventory was used to understand the following: 1.) the predictive ability of student perceptions of safety on overall school climate; 2.) the relationship between geographic location and school climate; and 3.) the predictive ability of geographic location and school type on overall school climate. Participants were elementary school students, grades PreK through 8, from 30 elementary schools across the country, with approximately 4,500 student responses. Results showed that students’ perceptions of school safety predicted 80% of the variances in connection to ratings of school climate. There was also a significant relationship between geographic location and ratings of school climate, as students from suburban schools tended to rate their climate as more positive than students from urban or rural schools. Lastly, the results showed that together, school type and geographic location are not able to sufficiently predict ratings of school climate, only explaining 4% of the variance in school climate ratings

Distributed control in virtualized networks

The increasing number of the Internet connected devices requires novel solutions to control the next generation network resources. The cooperation between the Software Defined Network (SDN) and the Network Function Virtualization (NFV) seems to be a promising technology paradigm. The bottleneck of current SDN/NFV implementations is the use of a centralized controller. In this paper, different scenarios to identify the pro and cons of a distributed control-plane were investigated. We implemented a prototypal framework to benchmark different centralized and distributed approaches. The test results have been critically analyzed and related considerations and recommendations have been reported. The outcome of our research influenced the control plane design of the following European R&D projects: PLATINO, FI-WARE and T-NOVA

Flood propagation modelling with the Local Inertia Approximation: theoretical and numerical analysis of its physical limitations

Attention of the researchers has increased towards a simplification of the complete Shallow water Equations called the Local Inertia Approximation (LInA), which is obtained by neglecting the advection term in the momentum conservation equation. In the present paper it is demonstrated that a shock is always developed at moving wetting-drying frontiers, and this justifies the study of the Riemann problem on even and uneven beds. In particular, the general exact solution for the Riemann problem on horizontal frictionless bed is given, together with the exact solution of the non-breaking wave propagating on horizontal bed with friction, while some example solution is given for the Riemann problem on discontinuous bed. From this analysis, it follows that drying of the wet bed is forbidden in the LInA model, and that there are initial conditions for which the Riemann problem has no solution on smoothly varying bed. In addition, propagation of the flood on discontinuous sloping bed is impossible if the bed drops height have the same order of magnitude of the moving-frontier shock height. Finally, it is found that the conservation of the mechanical energy is violated. It is evident that all these findings pose a severe limit to the application of the model. The numerical analysis has proven that LInA numerical models may produce numerical solutions, which are unreliable because of mere algorithmic nature, also in the case that the LInA mathematical solutions do not exist. The applicability limits of the LInA model are discouragingly severe, even if the bed elevation varies continuously. More important, the non-existence of the LInA solution in the case of discontinuous topography and the non-existence of receding fronts radically question the viability of the LInA model in realistic cases. It is evident that classic SWE models should be preferred in the majority of the practical applications

SDN workload balancing and QoE control in next generation network infrastructures

The increasing demand of bandwidth, low latency and reliability, even in mobile scenarios, has pushed the evolution of the networking technologies to satisfy new requirements of innovative services. Flexible orchestration of network resources is increasingly being investigated by the research community and by the service operator companies as a mean to easily deploy new remunerative services while reducing capital expenditures and operating expenses. In this regard, the Future Internet initiatives are expected to improve state of the art technologies by developing new orchestrating platforms based on the most prominent enabling technologies, namely, Software Defined Network (SDN) orchestrated Network Function Virtualization (NFV) infrastructure. After introducing the fundamental of the Next Generation Network, formalized as the conceptual Future Internet Platform architecture, the reference scenarios and the proposed control frameworks are given. The thesis discusses the design of two resources management framework of such architecture, targeted, respectively, (i) at the balancing of SDN Control traffic at the network core and (ii) at the user Quality of Experience (QoE) evaluation and control at the network edge. Regarding the first framework, to address the issues related with the adoption of a logically centralized but physically distributed SDN control plane, a discrete-time, distributed, non-cooperative load balancing algorithm is proposed, based on game theory and converged to a specific equilibrium known as Wardrop equilibrium. Regarding the QoE framework, a cognitive approach is presented, aimed at controlling the Quality of Experience (QoE) of the end users by closing the loop between the provided QoS and the user experience feedbacks parameters. QoE Management functionalities are aimed at approaching the desired QoE level exploiting a mathematical model and methodology to identify a set of QoE profiles and an optimal and adaptive control strategy based on a Reinforcement Learning algorithm. For both the proposed solutions, simulation and proof-of-concept implementation results are presented and discussed, to highlight the correctness and the effectiveness of the proposed solutions

Steady-state solution to the conduction problem of a spherical balloon radiometer, phases 1 and 2

A satellite system proposed for observing the earth's radiation balance employing spherical balloon radiometers is investigated. In the steady-state condition of radiative equilibrium, the magnitudes of absorbed external irradiances are sensed by internal radiometers mounted on the skin of each balloon. The temperatures of the radiometers are monitored as a measure of the balloons' internal irradiances (equal to absorbed external irradiances) and telemetered to earth. The effect of the magnitude of irradiant sources, balloon thickness, and thermal conductivity on the conduction of heat is assessed mathematically in order to determine its impact on measurement accuracy. Results indicate that observations are acceptable during daytime and nighttime modes of operation

A Derivative Recovery Spectral Volume model for the analysis of constituents transport in one-dimensional flows

The treatment of advective fluxes in high-order finite volume models is well established, but this is not the case for diffusive fluxes, due to the conflict between the discontinuous representation of the solution and the continuous structure of analytic solutions. In this paper, a derivative reconstruction approach is proposed in the context of spectral volume methods, for the approximation of diffusive fluxes, aiming at the reconciliation of this conflict. Two different reconstructions are used for advective and diffusive fluxes: the advective reconstruction makes use of the information contained in a spectral cell, and allows the formation of discontinuities at the spectral cells boundaries; the diffusive reconstruction makes use of the information contained in contiguous spectral cells, imposing the continuity of the reconstruction at the spectral cells boundaries. The method is demonstrated by a number of numerical experiments, including the solution of shallow-water equations, complemented with the advective-diffusive transport equation of a conservative substance, showing the promising abilities of the numerical scheme proposed

The exact solution to the Shallow water Equations Riemann problem at width jumps in rectangular channels

Riemann problems at geometric discontinuities are a classic and fascinating issue of hydraulics. In the present paper, the complete solution to the Riemann problem of the one-dimensional Shallow water Equations at monotonic width discontinuities is presented. This solution is based on the assumption that the relationship between the states immediately to the left and to the right of the discontinuity is a stationary weak solution of the one-dimensional variable-width Shallow water Equations. It is demonstrated that the solution to the Riemann problem always exists and it is unique, but there are cases where three solutions are possible. The appearance of multiple solutions is connected to a phenomenon, known as hydraulic hysteresis, observed for supercritical flow in contracting channel. The analysis of a Finite Volume numerical scheme from the literature (Cozzolino et al. 2018b) shows that the algorithm captures the solution with supercritical flow through the width discontinuity when multiple solutions are possible. Interestingly, the one-dimensional variable-width Shallow water Equations are formally identical to the one-dimensional Porous Shallow water Equations, implying that the exact solutions and the numerical scheme discussed in the present paper are relevant for two-dimensional Porous Shallow water numerical models aiming at urban flooding simulations. The exact solution presented here may be used not only as a benchmark, but also as a guide for the construction of new algorithms, and it can be even embedded in an exact solver

Friction decoupling and loss of rotational invariance in flooding models

Friction decoupling, i.e. the computation of friction vector components making separate use of the corresponding velocity components, is common in staggered grid models of the SWE simplifications (Zero-Inertia and Local Inertia Approximation), due to the programming simplicity and to the consequent calculations speed-up. In the present paper, the effect of friction decoupling has been studied from the theoretical and numerical point of view. First, it has been found that friction vector decoupling causes the reduction of the computed friction force and the rotation of the friction force vector. Second, it has been demonstrated that decoupled-friction models lack of rotational invariance, i.e. model results depend on the alignment of the reference framework. These theoretical results have been confirmed by means of numerical experiments. On this basis, it is evident that the decoupling of the friction vector causes a major loss of credibility of the corresponding mathematical and numerical models. Despite the modest speed-up of decoupled-friction computations, classic coupled-friction models should be preferred in every case

Longitudinal Monitoring of Gait Parameters for Lower Limb Prosthetic Users with Physical Therapy Using Video-Based Gait Analysis

Introduction Gait training in physical therapy is a common standard of practice for new lower limb prosthetic users. Progress is typically assessed through functional outcome measures such as the 10-meter or 6-minute walk tests1. While these tests measure walking speed and endurance, they fall short of capturing gait quality or quantifying gait parameters which literature shows to be of therapeutic value 2,3. Routine access to quantitative gait assessment could provide clinicians with benchmarks to optimize treatment interventions. Traditional gait analysis systems require specialized equipment making them very resource-intensive and inconvenient to operate. Using human pose estimation techniques, we have developed and trained a custom gait analysis system that allows us to measure spatiotemporal gait parameters from video4,5. Lower limb prosthetic users were recorded while ambulating during routine physical therapy appointments. Manual annotation of these videos was used to categorize system performance. The goal of the study was to demonstrate if longitudinal tracking of various gait parameters such as cadence and velocity across numerous subjects showed improvements that reflected coinciding functional outcome measures.https://jdc.jefferson.edu/aoa_research_symposium_posters/1004/thumbnail.jp