scholarly journals Monte Carlo tests of small-world architecture for coarse-grained networks of the United States railroad and highway transportation systems

2015 ◽  
Vol 438 ◽  
pp. 32-39 ◽  
Author(s):  
Preston R. Aldrich ◽  
Jermeen El-Zabet ◽  
Seerat Hassan ◽  
Joseph Briguglio ◽  
Enela Aliaj ◽  
...  
Keyword(s):  
United States ◽  
Monte Carlo ◽  
Small World ◽  
The United States ◽  
Transportation Systems ◽  
Coarse Grained ◽  
Highway Transportation

scholarly journals The Cost-Effectiveness of Epilepsy Surgery and Surgical Evaluation in the United States

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Shehryar R Sheikh ◽  
Michael P Steinmetz ◽  
Michael W Kattan ◽  
Mendel Singer ◽  
Belinda Udeh ◽  
...  
Keyword(s):  
United States ◽  
Monte Carlo ◽  
Cost Effectiveness ◽  
Epilepsy Surgery ◽  
Medical Management ◽  
Cost Effective ◽  
The United States ◽  
Effective Strategies ◽  
Surgical Evaluation ◽  
The Cost

Abstract INTRODUCTION Surgery is an effective treatment for many pharmacoresistant temporal lobe epilepsy patients, but incurs considerable cost. It is unknown whether surgery and surgical evaluation are cost-effective strategies in the United States. We aim to evaluate whether 1) surgery is cost-effective for patients who have been deemed surgical candidates when compared to continued medical management, 2) surgical evaluation is cost-effective for patients who have drug-resistant temporal epilepsy and may or may not ultimately be deemed surgical candidates METHODS We use a Monte Carlo simulation method to assess the cost-effectiveness of surgery and surgical evaluation over a lifetime horizon. Patients transition between two health states (‘seizure free’ and ‘having seizures’) as part of a Markov process, based on literature estimates. We adopt both healthcare and societal perspectives, including direct healthcare costs and indirect costs such as lost earnings by patients and care providers. We estimate variability of model predictions using probabilistic and deterministic sensitivity analyses. RESULTS 1) Epilepsy surgery is cost effective in surgically eligible patients by virtue of being cost saving and more effective than medical management in the long run, with 95% of 10 000 Monte Carlo simulations favoring surgery. From a societal perspective, surgery becomes cost effective within 3 yr. At 5 yr, surgery has an incremental cost-effectiveness ratio (ICER) of $31,600, which is significantly below the societal willingness-to-pay (∼ $100,000/quality-adjusted life years (QALY)) and comparable to hip/knee arthroplasty. 2) Surgical evaluation is cost-effective in pharmacoresistant patients even if the probability of being deemed a surgical candidate is low (5%-10%). Even if the probability of surgical eligibility is only 10%, surgical referral has an ICER of $96,000/QALY, which is below societal willingness-to-pay. CONCLUSION Epilepsy surgery and surgical evaluation are both cost-effective strategies in the United States. Pharmacoresistant temporal lobe epilepsy patients should be referred for surgical evaluation without hesitation on cost-effectiveness grounds.

Development of Performance Requirements for a Rail Passenger Workstation Table Safety Standard

2010 ◽  
Author(s):  
Michelle Muhlanger ◽  
Daniel Parent ◽  
Kristine Severson ◽  
Benjamin Perlman
Keyword(s):  
United States ◽  
Public Transportation ◽  
Injury Risk ◽  
Dynamic Models ◽  
The United States ◽  
Transportation Systems ◽  
Initial Stiffness ◽  
Safety Standard ◽  
Sled Test ◽  
Draft Standard

The American Public Transportation Association’s (APTA) Construction and Structural committee, a railroad industry group, with the support of the Federal Railroad Administration (FRA) and the John A. Volpe National Transportation Systems Center (Volpe Center), is creating an industry safety standard for an energy absorbing table. Workstation tables in passenger trains are an increasingly popular seating configuration both in the United States and abroad. Although a well-attached table can provide convenience and compartmentalization for the occupant, there is a risk of abdominal injury during a rail accident. In Fact, there have been several accidents in the United States in which impacts with workstation tables have severely or fatally injured occupants. In 2006, in response to these injuries, an FRA sponsored program developed a prototype table that distributed load over a wider area of the abdomen and absorbed energy during a collision. This table design was tested with specialized anthropomorphic test devices (ATDs) instrumented to measure abdominal impact response and was shown to decrease injury risk compared to a baseline table design. Building on the knowledge gained in the development of the prototype table, the proposed standard requires force to the abdomen be limited while energy is absorbed by the table. Since manufacturers do not have access specialized ATDs, researchers proposed a two part testing requirement. The first part is a quasi-static test which measures the energy absorption capacity of the table with a maximum force level determined from testing with specialized abdominal ATDs. The second part is a sled test with a standard Hybrid III 50th percentile (HIII) ATD to assess compliance with occupant protection standards of compartmentalization and ATD injury assessment reference values (IARVs). This paper discusses the research performed to develop the performance requirement in the draft standard. Current injury measures, originally developed for the automotive industry, were examined to assess their applicability to workstation table impacts. Multiple Mathematical Dynamic Models (MADYMO) model simulations show the estimated injuries during a simulated sled test scenario. Several force-crush parameters were examined, including the initial stiffness of the force-crush curve, the plateau force and the target energy absorbed by the table, to determined the force-crush design characteristics of a table that are likely to reduce injury risk. The results of this study, combined with testing of the current prototype table described in a companion paper [1], led to a draft standard that will greatly improve the safety of workstation tables in passenger rail cars.

In Search of Eden

Experiment ◽  
2014 ◽  
Vol 20 (1) ◽  
pp. 260-296
Author(s):  
Lynn Garafola
Keyword(s):  
United States ◽  
Monte Carlo ◽  
Southern California ◽  
The United States ◽  
Creative Work ◽  
Midsummer Night's Dream ◽  
Professional Careers ◽  
A Midsummer Night's Dream ◽  
Approach To Teaching ◽  
The 1960S

Bronislava Nijinska spent the last thirty-two years of her life in Southern California. Beginning with her first visit to Hollywood in 1934 to choreograph the dances in A Midsummer Night’s Dream, this essay examines her activities in California both as a teacher and a choreographer. It looks closely at her Hollywood bowl season of 1940, when she staged three of her ballets, all new to the United States; the dancers she trained who went on to distinguished professional careers, and her approach to teaching. It briefly summarizes her activities in the 1940s, when she choreographed for Ballet Theatre, Ballet Russe de Monte Carlo, and Ballet International; the 1950s, when she worked for the Grand Ballet du Marquis de Cuevas; and the 1960s, when the revival of Les Noces and Les Biches by the Royal Ballet brought her most celebrated works back into repertory. Finally, it speculates on the reasons she settled in California, given the limited opportunities it offered her for creative work.

scholarly journals Towing Vessel Safety: Risk-Based Maintenance and Inspection of Towing Vessel Machinery and Systems

2013 ◽  
Author(s):  
Bartley J. Eckhardt ◽  
Peter D. Squicciarini
Keyword(s):  
United States ◽  
The United States ◽  
Transportation Systems ◽  
Coast Guard ◽  
United States Coast Guard ◽  
Marine Transportation ◽  
Safety Risk ◽  
Incident Data ◽  
Maintenance And Inspection

Failures of machinery and systems aboard towing vessels can have devastating consequences to the vessel, its crew, other vessels and their crews, shoreside populations and facilities, cargoes, marine transportation systems, commerce, and the environment. This paper presents a comprehensive methodology for implementing Risk-Based Maintenance and Inspections of towing vessel machinery and systems. Utilizing incident data from the United States Coast Guard (USCG) and other relevant industry information, the authors apply the principles set forth in ANSI/API Recommended Practice 580, Risk-based Inspection [1], as a guideline. Relatively straightforward to implement, the methodology presented in this paper is expected to improve towing vessel safety, reduce potential dangers associated with towing operations, and provide favorable risk/benefit reward to vessel owners. Paper published with permission.

scholarly journals Examining the Relationship between Household Vehicle Ownership and Ridesharing Behaviors in the United States

2018 ◽  
Vol 10 (8) ◽  
pp. 2720 ◽  
Author(s):  
Yuanyuan Zhang ◽  
Yuming Zhang
Keyword(s):  
United States ◽  
Population Density ◽  
Negative Binomial ◽  
Negative Binomial Regression ◽  
Cost Effective ◽  
The United States ◽  
Potential Effect ◽  
Transportation Systems ◽  
Transport Systems ◽  
Vehicle Ownership

To improve the sustainability and efficiency of transport systems, communities and government agencies throughout the United States (US) are looking for ways to reduce vehicle ownership and single-occupant trips by encouraging people to shift from driving to using more sustainable transport modes (such as ridesharing). Ridesharing is a cost-effective, sustainable and effective alternative transportation mode that is beneficial to the environment, the economy and society. Despite the potential effect of vehicle ownership on the adoption of ridesharing services, individuals’ ridesharing behaviors and the interdependencies between vehicle ownership and ridesharing usage are not well understood. This study aims to fill the gap by examining the associations between household vehicle ownership and the frequency and probability of ridesharing usage, and to estimate the effects of household vehicle ownership on individuals’ ridesharing usage in the US. We conducted zero-inflated negative binomial regression models using data from the 2017 National Household Travel Survey. The results show that, in general, one-vehicle reduction in households was significantly associated with a 7.9% increase in the frequency of ridesharing usage and a 23.0% increase in the probability of ridesharing usage. The effects of household vehicle ownership on the frequency of ridesharing usage are greater for those who live in areas with a higher population density than those living in areas with a lower population density. Young people, men, those who are unable to drive, individuals with high household income levels, and those who live in areas with rail service or a higher population density, tend to use ridesharing more frequently and are more likely to use it. These findings can be used as guides for planners or practitioners to better understand individuals’ ridesharing behaviors, and to identify policies and interventions to increase the potential of ridesharing usage, and to decrease household vehicle ownership, depending on different contextual features and demographic variables. Comprehensive strategies that limit vehicle ownership and address the increasing demand for ridesharing have the potential to improve the sustainability of transportation systems.

Tankers and the U. S. Energy Environmental Analysis

1974 ◽  
Vol 11 (04) ◽  
pp. 340-364
Author(s):  
Joseph D. Porricelli ◽  
Virgil F. Keith
Keyword(s):  
United States ◽  
Transportation Cost ◽  
The United States ◽  
Transportation Systems ◽  
Ecological Problem ◽  
Energy Problem ◽  
Marine Transportation ◽  
The Past ◽  
Port Facilities ◽  
Marine System

The United States is facing an energy problem. The range of solutions varies from "the advancement of technology at any cost" to "a reversion to a bucolic society." Many of these solutions, while solving the energy problem, create an associated ecological problem. This paper illustrates a method by which additional oil can be safely imported to the U. S. by a marine transportation system. This marine system actually reduces the transportation cost of providing this energy and, more importantly, reduces the ecological damage to the oceans and beaches when compared with existing systems. The prospect of increasing oil imports for the United States at six or seven times the rate experienced in the past decade adds a new dimension to U. S. external petroleum logistics, particularly with respect to tankers and port facilities to accommodate them. The paper is divided into four major areas:The U. S. energy situation and projected oil requirements;economics of tankers to import that oil to the U. S.;the environmental impact of tanker transportation systems upon the U. S.; andthe cost and effectiveness of those systems.

Living Environment, Mobility, and Wellbeing among Seniors in the United States: A New Interdisciplinary Dialogue

2020 ◽  
Vol 35 (3) ◽  
pp. 298-314 ◽  
Author(s):  
Shengxiao (Alex) Li
Keyword(s):  
United States ◽  
Older Adults ◽  
The United States ◽  
Transportation Systems ◽  
Living Environment ◽  
Future Research ◽  
Older Population ◽  
Demographic Profile ◽  
Interdisciplinary Dialogue ◽  
The Relationship

In view of the demographic profile of the older adults in the United States, in the next two decades, cities and communities need to adapt the form, environment, and transportation systems to accommodate the growing aging population. In this article, I review two streams of literature in the mobility among the older population: the mobility/living environment and wellbeing; the relationship between living environment and mobility. I argue that two streams of literature should be combined to inform an interdisciplinary dialogue and a new agenda for future research.

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