Crash cushion selection criteria

Crash cushions are used as a roadside safety treatment alternative to protect errant vehicles from striking potentially hazardous roadside fixed objects. A variety of crash cushion designs, with varying characteristics, are available for use by transportation agencies. The choice of an optimum cushion type in consideration of safety performance and economic viability at any given highway location depends on several factors. This research study aims to quantify the life cycle costs of different crash cushion systems installed across the state of Iowa and to develop guidance to help decide where and when to install specific types of cushions. A probability-based tool, the Roadside Safety Analysis Program, was used to estimate the frequency of run-off-the-road collisions under different scenarios for one-way, undivided, and divided highway facilities. The estimated impact frequency based on pertinent inputs was then used as a decision criteria to select the most appropriate cushion category. Two general crash cushion categories were defined. These included redirective cushions with higher installation and lower repair costs and redirective cushions with lower installation and higher repair costs. The life cycle cost comparison indicated that the low-installation/high-repair category was optimum until an impact frequency of approximately 0.08 per year, beyond that value, high-installation/low-repair tended to be more cost-effective

PS-Sim: A Framework for Scalable Simulation of Participatory Sensing Data

Emergence of smartphone and the participatory sensing (PS) paradigm have paved the way for a new variant of pervasive computing. In PS, human user performs sensing tasks and generates notifications, typically in lieu of incentives. These notifications are real-time, large-volume, and multi-modal, which are eventually fused by the PS platform to generate a summary. One major limitation with PS is the sparsity of notifications owing to lack of active participation, thus inhibiting large scale real-life experiments for the research community. On the flip side, research community always needs ground truth to validate the efficacy of the proposed models and algorithms. Most of the PS applications involve human mobility and report generation following sensing of any event of interest in the adjacent environment. This work is an attempt to study and empirically model human participation behavior and event occurrence distributions through development of a location-sensitive data simulation framework, called PS-Sim. From extensive experiments it has been observed that the synthetic data generated by PS-Sim replicates real participation and event occurrence behaviors in PS applications, which may be considered for validation purpose in absence of the groundtruth. As a proof-of-concept, we have used real-life dataset from a vehicular traffic management application to train the models in PS-Sim and cross-validated the simulated data with other parts of the same dataset.Comment: Published and Appeared in Proceedings of IEEE International Conference on Smart Computing (SMARTCOMP-2018

A technique for solving system of generalized Emden-Fowler equation using Legendre wavelet

This article is concerned with the development of an efficient numerical algorithm for the solution of a system of generalized nonlinear Emden-Fowler equation. The proposed algorithm is based on the Legendre wavelet operational matrix of integration technique. This method decreases the storage and computational complexity due to its calculation on the subinterval [ (n-1)/2^(k-1) , n/2^(k-1)) of [0,1]. The main highlight of this method is to converts the system of the differential equation into an equivalent system of nonlinear algebraic equations, which greatly simplifies approximation. Some numerical example shows that the proposed scheme is very efficient and reliable.Publisher's Versio

Shock Waves in Dusty Gas with Radiation Effects

The jump conditions across a three dimensional curved shock in dusty gas with radiation have been derived. The general Rankine-Hugoniot relations for a three dimensional curved shock in dusty gas with radiation are investigated. These relations differ considerably from those without radiation effects. The most important parameter is the ratio of radiation pressure to the pressure of the mixture (gas+dust), ie the radiation pressure number Rp. The successive approximations have been used for different cases depending upon the value of radiation pressure number. In certain cases, the result. may be expressed in terms of an effective ratio of specific heats and an effective dusty gas pressure. A general method of solution is given and some numerical results are obtained

Mines: The Local Welfare Effects of Mineral Mining in Developing Countries

Do residents of mining communities face health-wealth trade-offs? We conduct the first extensive investigation assessing this question using micro-data from communities near about 800 mineral mines in 44 developing countries. Mining communities enjoy a substantial medium term rise in asset wealth (0.3σ), but experience a nine percentage point increase in anemia among adult women, and a five percentage point increase in the prevalence of stunting in young children. Both of these health impacts have previously been linked to metal toxicity - and in particular, exposure to high levels of environmental lead. Benefits and costs are strongly concentrated in the immediate vicinity (5km) of the nearest mine. We find no systematic evidence of general ill health, and we observe health impacts only near mines of a type where lead pollution is to be expected. Identification is based on a mine-level and mother-level panel, and in the cross-section, on group effects. A novel instrumental variable serves as a cross-sectional robustness check. To make plausible that the observed health impacts are due to pollution, we develop difference-in-difference tests based on the known association of certain mine types with lead pollution, and based on the pathophysiology of lead toxicity. Our results represent the first comprehensive assessment of the local welfare impacts of mining in developing countries, and add to the evidence suggesting that communities near industrial centers in developing countries face information or cost constraints that limit their choice sets

Three Dimensional Shock Waves in a Gaseous Medium Containing Dust Particles

In this Paper the discontinuous jump in the flow parameters such as density, Pressure, energy, velocity, enthalpy, entropy, etc., across the three dimensional shock wave in a dusty medium which is a homogeneous mixture of a perfect gas and dust particles with no heat conduction or viscosity has been computed. We have also obtained the relations for density shock strength and pressure shock strength respectively in a medium