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Speed Limits (speed + limit)

Distribution by Scientific Domains

Medical Sciences	33%
Business, Economics, Finance and Accounting	33%

Selected Abstracts

Control Strategy for Biventricular Assistance with Mixed-Flow Pumps

ARTIFICIAL ORGANS, Issue 8 2000
George Endo
Abstract: A left ventricular assist device (LVAD) is an effective method to rescue severe heart failure. Although some require a biventricular assist, the control method for the biventricular assist device (BVAD) with a rotary pump is rarely shown. The objective of this study was to investigate the strategy for controlling BVAD with rotary pumps by in vivo studies. Using 5 piglets, we set a BVAD through a left thoracotomy and made global ischemia for 30 min by clamping the base of the ascending aorta. After unclamping, the analysis of pumping performance acted for 6 h reperfusion. We set the target flow of the LVAD and set the right ventricular assist device (RVAD) speed limit as less than when the atrial collapse occurs. To detect the ventricular collapse without any specific sensor, we calculated the index of current amplitude from motor current waveform and simultaneous mean current value. In all cases, over 6 h of observation was performed, and the RVAD was weaned almost automatically. [source]

A Speed Limit Monetary Policy Rule for the Euro Area,

INTERNATIONAL FINANCE, Issue 1 2007
Livio StraccaArticle first published online: 5 APR 200
The main task of central banks is to set the level of short-term nominal interest rates in reaction to economic developments, with the aim of achieving their statutory objectives (typically some combination of inflation and output variability). If agents are forward-looking, central banks can achieve better macroeconomic outcomes by committing to follow a rule-like behaviour. Against this background, the contribution of this paper is twofold. First, it estimates a small-scale model of the euro area economy that can be used as a benchmark for the evaluation of different simple policy rules in the euro area economy. Second, it studies the performance of a relatively new type of rule, labelled ,speed limit' (SL), where the nominal interest rate reacts to the rate of growth in the output gap. The main conclusion of the study is that an SL policy performs remarkably well. [source]

Has the Tradeoff Between Productivity Gains and Job Growth Disappeared?

KYKLOS INTERNATIONAL REVIEW OF SOCIAL SCIENCES, Issue 1 2005
Paul Cavelaars
SUMMARY ,Policymakers' efforts to boost trend output growth may be hampered by the presence of a trade-off between productivity gains and job creation. This paper presents empirical evidence that the negative relationship between productivity growth and employment growth that prevailed in the 1960s and 1970s has disappeared since then. This finding is robust to using alternative measures and including other explanatory variables. The improved trade-off may be good news for policymakers who aim at raising the ,speed limit' of the economy. ZUSAMMENFASSUNG Die Bemühungen der politischen Entscheidungsträger, das Produktionswachstum nachhaltig anzu-kurbeln, können durch einen Trade-Off zwischen Produktivitätssteigerung und Schaffung von Arbeitsplätzen behindert werden. Der vorliegende Artikel erbringt empirische Belege dafür, dass heute das negative Verhältnis zwischen Produktivitätssteigerung und Zunahme der Beschäftigung, wie man es in den 1960er und 70er Jahren beobachtete, nicht mehr besteht. Dieses Ergebnis hält auch alter-nativen Messmethoden und der Berücksichtigung anderer erklärender Variablen stand und könnte eine gute Nachricht für die Politiker sein, die bestrebt sind, die ,Höchstgeschwindigkeit' für das Wirtschaftswachstum anzuheben. [source]

State motor vehicle laws and older drivers

HEALTH ECONOMICS, Issue 4 2005
Michael A. Morrisey
Abstract After teenage males, elderly individuals have the highest per capita motor vehicle fatality rate in the United States. Surprisingly, there has been only limited work examining the effect of state motor vehicle laws on older driver fatalities. This paper uses state-level data from the 1985,2000 Fatality Analysis Reporting System to examine the effects of changes in state laws dealing with license renewal, seatbelt use, speed limits, and driving while intoxicated on fatalities among drivers and others aged 65 and over. Negative binomial regressions are estimated using alternatively state and year fixed effects, or age and year fixed effects. In-person license renewal reduced fatalities among the oldest drivers, but vision tests, road tests and the length of the license renewal cycle generally did not. In terms of policies that apply to all drivers, seatbelt laws, particularly with primary enforcement, were generally the only policies that reduced older driver fatalities. These results are noteworthy because a number of policies that have been effective towards increasing younger driver safety are not relevant for older drivers, implying that policymakers must think broadly about using state laws to improve older driver safety. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Effect of variable message signs on driver speed behavior on a section of expressway under adverse fog conditions,A driving simulator approach

JOURNAL OF ADVANCED TRANSPORTATION, Issue 1 2006
V. Ganesh Babu Kolisetty
Abstract Variable message signs (VMS) are used to provide dynamic information and one current application is to show different speed limits under different conditions. As speed is an important contributor to road accidents and also affects driver speed behavior, the present study focuses on how effective traffic advisory information is when helping drivers to divert from potentially dangerous conditions. Graphical representation of an Expressway section made it easy to isolate the effects of speed etc. by drivers with information provided through VMS under adverse fog conditions. Understanding and reacting to the VMS system by drivers is essential for its success. If drivers do not react by changing speed behavior then the VMS system will fail and further implementation may cease. In this paper an Analysis of Variance model, which is appropriate to the proposed experimental conditions, is used to study how subjects (drivers) will perceive provided information and also to find the effect of VMS on driver speed behavior on the simulated Expressway section. [source]

Driving speed changes and subjective estimates of time savings, accident risks and braking

APPLIED COGNITIVE PSYCHOLOGY, Issue 4 2009
Ola Svenson
Participants made decisions between two road improvements to increase mean speed. Time saved when speed increased from a higher driving speed was overestimated in relation to time saved from increases from lower speeds. In Study 2, participants matched pairs of speed increases so that they would give the same time saving and repeated the bias. The increase in risk of an accident with person injury was underestimated and the increase in risk of a fatal accident grossly underestimated when speed increased. The increase of stopping distance when speed increased was systematically underestimated. In Study 3, the tasks and results of Study 2 were repeated with engineering students. When forming opinions about speed limits and traffic planning, drivers, the public, politicians and others who do not collect the proper facts are liable to the same biases as those demonstrated in the present study. Copyright © 2008 John Wiley & Sons, Ltd. [source]