[1] Diurnal cycles in snow-fed streams provide a useful technique for measuring the time it takes water to travel from the top of the snowpack, where snowmelt typically peaks in the afternoon, to the river gauge, where the daily maximum flows may arrive many hours later. Hourly stage measurements in nested subbasins (6–775 km) of the Tuolumne River in Yosemite National Park illustrate travel ti...

In 1998, the Portuguese Communications Foundation signed a protocol with the University of Coimbra for the development of academic research into the history of communications, from the times predating the institutionalisation of the Postmaster-General in Portugal, at the dawn of the 16th century, down to the present day. In the past, Portuguese historiographers have paid scant attention to the ...

The Internet is an interconnected mesh of participating IP devices forwarding information worldwide. The speed and volume with which this information travels can vary due to limitations in channel capacity, type & size of media and device capacity. The primary devices, which handle routing decisions on the Internet Backbone, are gateways. The efficiency of gateways at forwarding traffic can be ...

In order to improve service reliability, many transit agencies add a significant amount of slack in the schedule. However, too much slack in the schedule reduces service frequency. We study the problem of determining the optimal slack that minimizes the passengers’ expected waiting times under schedule-based control. By associating with a D/G/c queue model, we show that the system is stable if ...

this paper extends certain results of iglehart and whitt on multiple channel queues to the case where the inter-arrival times and service times are not necessarily identically distributed. it is shown that the weak convergence results in this case are exactly the same as those obtained by iglehart and whitt

This paper presents the results from an investigation in the use of vehicle reidentification for deriving travel time and travel time distributions using loop and video detectors. Vehicle reidentification is the process of tracking vehicles anonymously from site to site thus yielding individual vehicle travel times and overall travel time distribution. Travel time and travel time distribution a...

Travel times in congested transportation networks are time-varying quantities that can at best be known a priori probabilistically. In such networks, the arc weights (travel times) are represented by random variables whose probability distribution functions vary with time. These networks are referred to herein as stochastic, time-varying, or STV, networks. The determination of ‘‘least time’’ ro...

introduction: parkinsonrquote s disease (pd) is a human neurodegenerative disorder which is associated with a massive and progressive degeneration of dopaminergic neurons in subistantia nigra (sn). there is a strong evidence of an oxidative stress participates in the etiology of pd. materials and methods: the rats were divided into sham-operated, experimental and vitamin e-treated groups. for a...