Sharif Digital Repository

In this paper, the concept of environmental capacity is developed to identify a convenient maximum traffic volume which will not reduce the life quality of residents. The presented method investigates the idea of traffic capacity under environmental constraints by calculating the maximum number of vehicles allowed on roads based on acceptable levels of air and noise pollutants. In this study, the permissible noise pollution level and permissible levels of CO and NOx pollution are considered for determining environmental capacity. Results show the significant difference between environmental capacity and functional traffic capacity, introduced by the highway capacity manual (HCM) as a... 

Systematic management of enterprise knowledge, e.g. new ideas, innovations and patents, has a great impact on business sustainability and growth. Without comprehensive assessment of knowledge assets, agile companies can not design and run knowledge promotion programs required for survival in competitive environments in modern economy. A comprehensive framework for the assessment of as-is situation and development of knowledge promotion plans includes (a) assessing the as-is situation- the quantity and quality of organizational knowledge; (b) developing a situational program based on assessment results, business strategy and knowledge maturity indicators; (c) and working out an action plan in... 

Traffic modeling, traffic decomposition, and traffic engineering are some of the applications of traffic characterization that are mainly based on statistical characteristics of the network traffic. Many empirical analyses on Internet traffic traces show that the flow inter-arrival time distribution generally follows the Weibull distribution. As the scale of the network becomes larger, the Weibull distribution degrades to the Poisson distribution and when the flow arrival rate is high, it asymptotically converges to the Normal distribution. The aggregated traffic on high bandwidth links is the result of statistical multiplexing of many traffic sources, and the flow arrival rate on these... 

Improvement of energy efficiency in Software Defined Networking (SDN) is a challenging problem. In order to achieve higher energy efficiency, the routing and scheduling in software defined networks should be planned robustly based on the topological specifications of the SDN. The topological specifications of the SDN depends on the size of the network graph which changes rapidly as the virtualized network devices in the network turned on and off by the controller. Therefore, modelling the SDN graph is an important issue in designing a reliability aware energy efficient SDN. In this paper we propose a new algorithm for reliable energy efficient traffic engineering in SDN. In the proposed... 

In traffic engineering, one of the problems presented by slate pavement, besides being costly to repair and maintain, is the insufficient resistance of bitumen against traffic loads in low temperatures. In this study, the effect of synthesized basalt modifier has been assessed via four different tests to improve bitumen performance. Hence, the enhancement of resistance to traffic loads at low temperatures as an essential problem of asphalt superstructure in traffic engineering has been taken into account. The bending beam rheometer test was conducted at three temperatures of-6°C,-12°C, and-18°C, and the softening point and permeability index tests were performed. A Fourier transform infrared... 

Urban commuters and road authorities are interested in knowing how well their city can manage traffic conditions. It is challenging to make a fair comparison among global cities due to the absence of a consistent, publicly accessible and inexpensive framework. This study proposes a methodology to compare travel time and average speed in different cities. Large cities have a central core, in which many of the major activities take place. This core is called downtown or the central business district (CBD). In this study, a comparison is made by simulating the morning commute trips from origins outside to destinations inside the CBD. The proposed framework outlines how the city and the CBD... 

The Population Growth, Land-use Development and the Increase in Vehicle Ownership in big cities have caused an increase in Travel Demand and the volume of vehicles passing through Urban Routes. Travel Time in the urban route network due to increase in congestion in one of the most important problems in Metropolises. A considerable part of Travel Time in the Metropolitan routes network is related to delay time in intersections. Thus, controlling methods for intersections in order to decrease such delays is of a great importance. The application of Fuzzy Logic as a control basis in engineering issues has a proper background. In this study, a method for controlling such signalized intersections... 

Urban commuters and road authorities are interested in knowing how well their city can manage traffic conditions. It is challenging to make a fair comparison among global cities due to the absence of a consistent, publicly accessible and inexpensive framework. This study proposes a methodology to compare travel time and average speed in different cities. Large cities have a central core, in which many of the major activities take place. This core is called downtown or the central business district (CBD). In this study, a comparison is made by simulating the morning commute trips from origins outside to destinations inside the CBD. The proposed framework outlines how the city and the CBD...