نتایج جستجو برای: portable roadway
تعداد نتایج: 37657 فیلتر نتایج به سال:
The timing of traffic lights follows the code of uniform signalling devices. As such, the timing for crosswalks is determined by dividing the width of the roadway by 4. Four (4) is a magic number that corresponds to the walking speed of an adult male of ‘average’ age and dates back to some time in the 1950’s. Most importantly, a male of ‘average’ age most certainly does not represent the walkin...
The problem of roadway support in swelling soft rock was one of the challenging problems during mining. For most geological conditions, combinations of two or more supporting approaches could meet the requirements of most roadways; however, in extremely swelling soft rock, combined approaches even could not control large deformations. The purpose of this work was to probe the roadway deformatio...
This paper presents an empirical inquiry into the applicability of zero-altered counting processes to roadway section accident frequencies. The intent of such a counting process is to distinguish sections of roadway that are truly safe (near zero-accident likelihood) from those that are unsafe but happen to have zero accidents observed during the period of observation (e.g. one year). Tradition...
In this paper we examine the effect of different roadway configurations, including noise barriers and roadway elevation or depression relative to the surrounding terrain, on the dispersion of traffic-related pollutants for winds perpendicular to the roadway. A wind tunnel experiment modeling 12 different configurations was performed to study the flow fields and the concentration distributions r...
Many agencies use traffic crash data to identify problems, establish goals and performance measures, measure progress of specific programs, and support development and evaluation of highway and vehicle safety countermeasures. Traditionally, efforts have considered only crash data and roadway network attributes and have not taken adjacent demographics, socioeconomics, land use, and other non-roa...
background: exposure to loud music from sources such as portable music players (pmp), especially among adolescents, can lead to noise-induced hearing loss. the aims of this study are as follows: 1) investigate the prevalence of headphone use in iranian university students by assessing their behavior, 2) determine the type of headphones used, and 3) ascertain the type of music player used. metho...
Roadway traffic control is an important practical example of real time control applications, but effective roadway control is hampered by a variety of organizational, financial and technical considerations. One major hurdle is the current reliance on outmoded field hardware and software. A systematic approach to traffic engineering software development could provide significant advantages with ...
(the prime indicates differentiation with respect to x). P(x) and Q(x) (positive downward) are the live load per unit length and the dead load of the roadway, cable, and hangers per unit length. E and / (assumed constants) are the modulus of elasticity and moment of inertia of the roadway and H (constant) is the horizontal dead-load tension in the cable. The term h (constant), the induced live-...
A fire developing tendency mathematical model of mine fire zone under positive pressure ventilation was established and was validated based on the particularly serious fire accident of Fuhua “9.20” in Heilongjiang province. Then the law of positive pressure ventilation influence on the fire zone developing tendency and its enlightenment to work safety were obtained. Under positive pressure vent...
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