Sharif Digital Repository

In this paper, an attempt to identify and characterize minor road traffic behavior at unsignalized urban intersections in a city situated in a developing country is described. Information about the particular traffic behavior was collected using video cameras placed at 12 unsignalized intersections connecting minor to major roadways in Tehran. Stop signs and/or blinking red signals provided the stopping message at the minor approaches of the selected intersections. Relevant information about the behavior of more than 2400 vehicles was extracted from the video displays and the database records consisted of 31 variables reflecting driver, pedestrian, passenger, vehicle and intersection... 

In this paper, the results of a study comparing the performance of two types of interchange, i.e., Conventional Diamond Interchange and Single Point Urban Diamond Interchange, are reported. The analysis is based on simulation of a Single Point Urban Diamond Interchange. The real data that is collected from two different existing Conventional Diamond Interchanges during peak hours is used as input for analysis. Highway capacity software is used to analyze the performance of the Conventional Diamond Interchanges while a simulation model is used for analyzing the performance of the Single Point Urban Diamond Interchanges. The results indicate that the performance of the Single Point Urban... 

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... 

A very common phenomena in car-traffic system is investigated in this article. The problem is one-dimensional. We try to find the wave equation of the traffic and then, we'll talk more about the simulation of the system using Matlab7.6  

Analyzing motion patterns in traffic videos can be employed directly to generate high-level descriptions of their content. For traffic videos captured from intersections, usually, we can easily provide additional information about traffic phases. Such information can be obtained directly from the traffic lights or through traffic lights controllers. In this paper, we focus on incorporating additional information to analyze the traffic videos more efficiently. Using side information on traffic phases, the semantic of motion patterns from traffic intersection scenes can be learned more effectively. The learning is performed based on optical flow features extracted from training video clips,... 

Background: In recent years, Advanced Driving Assistance Systems (ADAS) have been significantly progressed, opening novel horizons in reducing traffic accidents. Driver gender can be an affecting factor in the utilization of these systems. The purpose of this study is to review articles examining the effect of gender on the use of ADAS technologies. Methods: This systematic review was conducted in Scopus, Science Direct and PubMed databases using defined key-words in 2018. The retrieved articles were managed and screened through PRISMA-P protocol using EndNote X7 software. The extracted variables were divided into three categories of reaction, behavior, and outcome and also the relevant... 

This paper presents an ITS project in Iran, as the first intelligent tunnel management system to be deployed in support of urban traffic management. It aims to protect highway users from possible hazards, provide them travel information and support traffic controllers in efficient and effective exercise of daily works. The project concerns a high trafficked tunnel which has been inaugurated in July 2006 to connect two parts of a highway in Tehran, linking the northwest districts to northeast ones. This corridor was selected as a good candidate, due in particular, to the variety of problems encountered [1]. In order to launch the project a co-operation has been negotiated in late 2005 between... 

The paper revisits the performance evaluation of caching in a Named Data Networking (NDN) router where the content store (CS) is supplemented by a pending interest table (PIT) which aggregates requests for a given content that arrive within the download delay. We extend prior work on caching with non-zero download delay by proposing a novel mathematical framework that is applicable to general traffic models and alternative cache insertion policies. Specifically we consider the impact of time locality in demand due to finite content lifetimes and we evaluate the use of an LRU filter to improve CS hit rate performance. The analysis is used to demonstrate that the impact of the PIT on upstream... 

Currently, some coarse measures like global network latency are used to compare routing protocols. These measures do not provide enough insight of traffic distribution among network nodes in presence of different fault regions. This paper presents a detailed traffic analysis of f-cube routing algorithm achieved by a especially developed tool. Per-node traffic analysis illustrates the traffic hotspots caused by fault regions and provides a great assistance in developing fault tolerant routing algorithms. Based on such detailed information, a simple yet effective improvement of f-cube is suggested. Moreover, the effect of a traffic hotspot on the traffic of neighboring nodes and global... 

Traffic pattern is a point of concern in today's modeling approach of network-based computing systems including NoCs and Clusters. Hypermesh is a promising network topology suitable for a range of networks. Although there are few models reported for hypermeshes with uniform traffic pattern, no analytical model has been reported yet that deal with hotspot traffic load. Since uniform traffic assumption is not always justifiable in practice as there are many parallel applications that exhibit non-uniform traffic patterns, which can produce hotspots in the network, in this study we propose a novel analytical model to analyze the mean message latency in wormhole-switched hypermesh in the presence... 

Regardless of existing types of transportation and traffic model and their applications, the essential input to these models is travel demand, which is usually described using origin–destination (OD) matrices. Due to the high cost and time required for the direct development of such matrices, they are sometimes estimated indirectly from traffic measurements recorded from the transportation network. Based on an assumed demand profile, OD estimation problems can be categorized into static or dynamic groups. Dynamic OD demand provides valuable information on the within-day fluctuation of traffic, which can be employed to analyse congestion dissipation. In addition, OD estimates are essential... 

The importance of traffic pattern prediction for traffic management systems has significantly increased in recent years. This paper presents a novel method to find unusual traffic patterns by using topic modeling. We have employed topic models to provide an abstraction of speed camera data from Tehran, the capital of Iran. In this methodology, topic modeling is applied to days of weeks and months in a year and extracts weekly and monthly traffic patterns. Analysis of the abstract descriptions and their adaptation to actual urban traffic patterns prove the effectiveness of the proposed method. The model training convergence is also practically verified. Based on our experiments, our method... 

The use of traffic information in the form of radio reports, as a solution to the problem of congestion, is one of the issues, which are of particular importance for large cities like Tehran. In this study, factors affecting the use of traffic information in the context of a developing country are examined for commuters in the city of Tehran using ordered logit models. Results based on the particular survey designed for this purpose are compared to those of a developed country. Regarding the use of information in the form of listening to the radio traffic reports, the models show that older commuters, commuters who adjust their departure time according to traffic conditions (those who are... 

The importance of traffic pattern prediction for traffic management systems has significantly increased in recent years. This paper presents a novel method to find unusual traffic patterns by using topic modeling. We have employed topic models to provide an abstraction of speed camera data from Tehran, the capital of Iran. In this methodology, topic modeling is applied to days of weeks and months in a year and extracts weekly and monthly traffic patterns. Analysis of the abstract descriptions and their adaptation to actual urban traffic patterns prove the effectiveness of the proposed method. The model training convergence is also practically verified. Based on our experiments, our method... 

Many theoretical-based comparison studies, relying on the graph theoretical viewpoints with using structural and algorithmic properties, have been conducted for the hypercube and the star graph. None of these studies, however, considered real working conditions and implementation limits. We have compared the performance of the star and hypercube networks for different message length and virtual channels and considered two implementation constraints, namely the constant bisection bandwidth and constant node pin-out. We use two accurate analytical models already proposed for the star graph and hypercube and implement the parameter changes imposed by technological implementation constraints....