Air Pollution is one of the significant problems in Tehran. Understanding the role of different sources can result in better decision-making. Some pollutions are not emitted directly from sources and are present in the atmosphere due to chemical reactions. Therefore, using air quality modeling can be beneficial to our understanding of these phenomena. An air quality modeling system was used fir...

PURPOSE The Children's Activity Rating Scale (CARS) is a rating scale that is used in direct observation of physical activity in children. Direct observation is costly and tedious, and accuracy may decrease as the observation period lengthens. Recently, motion sensors have gained acceptance for assessment of physical activity. The purpose of this study was to compare 6 h of activity levels usin...

In modern cities, a gradual increase of motorcycles and other types of Powered Two-Wheelers (PTW) are observed as an answer to long commuting in traffic jams and complex urban navigation. Such increasing penetration of PTW creates mixed traffic flow conditions with unique characteristics that are not well understood. Unlike cars, PTWs filter between cars, have unique dynamics, and do not respec...

cars are one of the most important symbols of modern technology which contain various social and cultural messages about concepts like gender, ethnicity, age, social class, etc. and are interpreted differently based on the needs and motivations of users. since the main aim of this research is having a deep look at use of cars among female drivers, we will first take a look at the conceptual rel...

There is a significant interaction between sizing a fleet of rail cars and its utilization. This paper presents a new multi-period mathematical model and a solution procedure to optimize the rail-car fleet size and freight car allocation, wherein car demands, and travel times, are assumed to be deterministic, and unmet demands are backordered. This problem is considered NP-complete. In other wo...

The third-order polarization for coherent anti-Stokes Raman scattering (CARS) from a pure state is described by 48 terms in perturbation theory, but only 4 terms satisfy the rotating wave approximation. They are represented by Feynman dual time-line diagrams and four-wave mixing energy level diagrams. In time-resolved (tr) fs and fs/ps CARS from the ground vibrational state, one resonant diagra...

Vehicular adhoc network (VANET) is an emerging network which is depend on the communication of data through vehicular network via data pushing. Data pushing in between the vehicles was done by the data pushing communication model. In this paper, we present a formal model of data dissemination in between the vehicles by the mobility of vehicles and describe also the affects of data dissemination...

We compare the energy efficiency of hybrid and fuel cell vehicles as well as conventional internal combustion engines. Our analysis indicates that fuel cell vehicles using hydrogen from fossil fuels offer no significant energy efficiency advantage over hybrid vehicles operating in an urban drive cycle. We conclude that priority should be placed on hybrid vehicles by industry and government.

Brownian motion is used to model the uncertainty in the motion of cars on a highway. The probability of collision of two adjacent cars within a fixed horizon is calculated and its implications are discussed. Moreover, the probability of collision in the presence of emergency braking is also obtained by modeling the occurrence of emergency braking as a Poisson process.