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Study on mobile phone use while driving in a sample of Iranian drivers
, Article International Journal of Injury Control and Safety Promotion ; 2016 , Pages 1-7 ; 17457300 (ISSN) ; Khademi, M ; Razi Ardakani, H ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
The use of cell phone is a significant source of driver distraction. Phone use while driving can impair a number of factors critical for safe driving which can cause serious traffic safety problems. The objective of this paper was to investigate the frequency of using cell phones while driving in Iran's roads through an observational survey with a random sample of drivers, to recognize contributing factors to cell phone usage and to understand the magnitude of the problem. A total of 1794 observations were collected from 12 sites at controlled intersections, entrance and exit points of highways. The cell phone use rate among drivers (talking or texting) was estimated at 10% which is...
Study on mobile phone use while driving in a sample of Iranian drivers
, Article International Journal of Injury Control and Safety Promotion ; Volume 24, Issue 2 , 2017 , Pages 256-262 ; 17457300 (ISSN) ; Khademi, M ; Razi Ardakani, H ; Sharif University of Technology
Taylor and Francis Ltd
2017
Abstract
The use of cell phone is a significant source of driver distraction. Phone use while driving can impair a number of factors critical for safe driving which can cause serious traffic safety problems. The objective of this paper was to investigate the frequency of using cell phones while driving in Iran's roads through an observational survey with a random sample of drivers, to recognize contributing factors to cell phone usage and to understand the magnitude of the problem. A total of 1794 observations were collected from 12 sites at controlled intersections, entrance and exit points of highways. The cell phone use rate among drivers (talking or texting) was estimated at 10% which is...
Estimating activity patterns using spatio-temporal data of cell phone networks
, Article International Journal of Urban Sciences ; 2017 , Pages 1-18 ; 12265934 (ISSN) ; Shafahi, Y ; Sharif University of Technology
Abstract
The tendency towards using activity-based models to predict trip demand has increased dramatically over recent years. However, these models have suffered from insufficient data for calibration, and the intrinsic problems of traditional methods impose the need to search for better alternatives. This paper discusses ways to process cell phone spatio-temporal data in a manner that makes it comprehensible for traffic interpretations and proposes methods on how to infer urban mobility and activity patterns from the aforementioned data. The movements of each subscriber are described by a sequence of stops and trips, and each stop is labelled by an activity. The types of activities are estimated...
Estimating activity patterns using spatio-temporal data of cell phone networks
, Article International Journal of Urban Sciences ; Volume 22, Issue 2 , 2018 , Pages 162-179 ; 12265934 (ISSN) ; Shafahi, Y ; Sharif University of Technology
Routledge
2018
Abstract
The tendency towards using activity-based models to predict trip demand has increased dramatically over recent years. However, these models have suffered from insufficient data for calibration, and the intrinsic problems of traditional methods impose the need to search for better alternatives. This paper discusses ways to process cell phone spatio-temporal data in a manner that makes it comprehensible for traffic interpretations and proposes methods on how to infer urban mobility and activity patterns from the aforementioned data. The movements of each subscriber are described by a sequence of stops and trips, and each stop is labelled by an activity. The types of activities are estimated...
Estimating activity patterns using spatio-temporal data of cellphone networks
, Article MATEC Web of Conferences, 6 July 2016 through 10 July 2016 ; Volume 81 , 2016 ; 2261236X (ISSN) ; Shafahi, Y ; Sharif University of Technology
EDP Sciences
2016
Abstract
The tendency towards using activity-based models to predict trip demand has increased dramatically over recent years, but these models have suffered insufficient data for calibration. This paper discusses ways to process the cellphone spatio-temporal data in a manner that makes it comprehensible for traffic interpretations and proposes methods on how to infer urban mobility and activity patterns from the aforementioned data. Movements of each subscriber is described by a sequence of stays and trips and each stay is labeled by an activity. The type of activities are estimated using features such as land use, duration of stay, frequency of visit, arrival time to that activity and its distance...
Urban Mobility Pattern Estimation Using O-D Surveys and Mobile Phone Data: A Case Study of Shiraz City
, M.Sc. Thesis Sharif University of Technology ; Shafahi, Yousef (Supervisor)
Abstract
Activity bases models of travel demand considers travel demand as a derived demand to fulfill activities. Development of these models cause better understanding of the mechanism of travel through Integrity, interdependencies, higher temporal and spatial aggregation, and behavioral basis. Although these models requires of spatial and temporal data with high resolution of huge number of peoples. Gathering this data through surveys require great labor and time. Mobile phone data of cellular network have high spatial-temporal resolution used for billing purposes and can be used as a supplementary source of data to develop activity based models. This research uses mobility patterns called motifs...
Trip-Chain-Based Travel-Mode-Shares Driven Framework Using Mobile Data
, M.Sc. Thesis Sharif University of Technology ; Shafahi, Yousef (Supervisor)
Abstract
The costly and time-consuming methods of traditional data collection through interviews or questionnaires have led researchers to use new methods, including mobile networks, to obtain the information they need. Information obtained from the mobile network has been widely used in recent studies due to features such as passive information generation, extensive coverage and low cost of data collection, and attempts have been made to use this information to model citizens activities and urban travel demand. However, extracting information such as travel patterns and mode share of transportation has been challenging given the nature of this type of data. This research pursues two goals separately...
Identification and Control of Robot Manipulators using Cell Phone Sensors
, M.Sc. Thesis Sharif University of Technology ; Namvar, Mehrzad (Supervisor)
Abstract
The goal of controlling robot manipulators is to perform the mission intended for its end effector. Model-based control is a solution that can achieve the control goal with high speed and accuracy in the presence or absence of environmental obstacles by using the knowledge of the robot model. In this thesis, the Armtin 5 robot model parameters were identified in two steps. In the first step, the gravity and friction parameters and in the second step, the dynamic parameters were estimated. In the estimation of gravity and friction parameters, the non-linear behavior of friction causes the estimated parameters to be accompanied by a large amount of error. Estimation of the parameters was...
Performance analysis of android underlying virtual machine in mobile phones
, Article IEEE International Conference on Consumer Electronics - Berlin, ICCE-Berlin ; 2012 , Pages 292-295 ; 21666814 (ISSN) ; 9781467315470 (ISBN) ; Sameki, M ; Goudarzi, M ; Sharif University of Technology
2012
Abstract
In recent years, Android is widely used in cell phones. Dalvik is the virtual machine which is embedded inside the Android operating system, and executes the Android-based applications. Thus, improving efficiency of the Dalvik virtual machine plays an important role in optimizing performance of android-based mobile phones. In this paper, we present a comprehensive analysis of the Dalvik bytecodes and their frequency of use in common Android applications and use the results to determine the most frequently used bytecodes in Dalvik virtual machine to identify best targets for improvement. Our analysis showed that over 82% of total execution time of our Android benchmarks is spent by only 5...
Transmission of non-linear binary input functions over a CDMA system
, Article IEEE International Symposium on Information Theory - Proceedings, 1 July 2012 through 6 July 2012 ; July , 2012 , Pages 1401-1405 ; 9781467325790 (ISBN) ; Gohari, A ; Aghaeinia, H ; Sharif University of Technology
2012
Abstract
We study the problem of transmission of binary input non-linear functions over a network of mobiles based on CDMA. Motivation for this study comes from the application of using cheap measurement devices installed on personal cellphones to monitor environmental parameters such as air pollution, temperature and noise level. Our model resembles the MAC model of Nazer and Gastpar except that the encoders are restricted to be CDMA encoders. Unlike the work of Nazer and Gastpar whose main attention is transmission of linear functions, we deal with non-linear functions with binary inputs. A main contribution of this paper is a lower bound on the computational capacity for this problem. While in the...
Speaker phone mode classification using Gaussian mixture models
, Article SPA 2011 - Signal Processing: Algorithms, Architectures, Arrangements, and Applications - Conference Proceedings, 29 September 2011 through 30 September 2011 ; September , 2011 , Pages 112-117 ; 9781457714863 (ISBN) ; Sobhan Manesh, F ; Sameti, H ; BabaAli, B ; Sharif University of Technology
2011
Abstract
This study focuses on the mode classification of phones speaker modes using GMM 1. In this regard, speech data in both enabled and disabled speaker modes of cell phones and telephones were collected, processed and classified into two different categories. The different mixture numbers (1 to 4) of GMM and wave files sizes of 10, 20, 40 and 80 kb were tested in order to obtain an optimal condition for classification. The GMM method attained 87.99% correct classification rate on test data. This classification is important for speech enabled IVR 2 systems [1], dialog systems and many systems in speech processing in the sense that it could help to load an optimum model for increasing system...
FTS: An efficient tree structure based tool for searching in large data sets
, Article ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering, 16 April 2010 through 18 April 2010 ; Volume 2 , April , 2010 , Pages 294-298 ; 9781424452644 (ISBN) ; Najafpour, M ; Mahdavi, M ; Ashurzad Delcheh, M ; Khalkhali, I ; Sharif University of Technology
2010
Abstract
This paper addresses the issue of finding and accessing desired items when a large amount of data items are concerned, by proposing some concepts based on Tree Search Structure -a hierarchical structure for information retrieval. The proposed concepts are applicable to several environments such as File Managers on PCs, help tree views, site maps, taxonomies, and cell phones. A software tool, FTS (File Tree Search), that is developed to utilize the proposed concepts is also presented
Data envelopment analysis based comparison of two hybrid multi-criteria decision-making approaches for mobile phone selection: a case study in Iranian telecommunication environment
, Article International Journal of Information and Decision Sciences ; Volume 1, Issue 2 , 2008 , Pages 194-220 ; 17567017 (ISSN) ; Fazlollahtabar, H ; Mozaffari, E ; Heidari, M ; Mahdavi Amiri, N ; Sharif University of Technology
2008
Abstract
The arrival of the mobile phone and its rapid and widespread growth may well be seen as one of the most significant developments in the fields of communication and information technology over the past two decades. The aim of this study is to compare two hybrid multi-criteria decision-making (MCDM) approaches to evaluate the mobile phone options with respect to user’s preferences. Firstly, we identify the most desirable features influencing the choice of a mobile phone. This is realised through a survey conducted among the target group, the experiences of the telecommunication sector experts and the studies in the literature. Secondly, two MCDM methods are used in the evaluation procedure....
Estimation of Origin-Destination Trip Matrix Using Spatio-Temporal Data of Cell Phone Networks Collected based on the PLU method
, M.Sc. Thesis Sharif University of Technology ; Shafahi, Yousef (Supervisor)
Abstract
Origin-destination (OD) matrix is one of the most important sources of information used in planning and management of transportation networks. Estimation of a precise OD matrix is a fundamental component for enabling the administrative authorities to optimize the use of their transportation network. Traditionally, urban planners use direct approaches including household questionnaires to estimate OD matrices. These methods are time-consuming and costly. Strategies that are more recent like Bluetooth, Wi-Fi, and RFID scanners and detectors include deficient precision and the additional cost of accessories. Exploiting GPS technology in spite of its high locating accuracy, due to user...
Ni and Cu recovery by bioleaching from the printed circuit boards of mobile phones in non-conventional medium
, Article Journal of Environmental Management ; Volume 250 , 2019 ; 03014797 (ISSN) ; Nili, S ; Yaghmaei, S ; Sharif University of Technology
Academic Press
2019
Abstract
There is a substantial volume of mobile phone waste every year. Due to the disadvantages of traditional methods, it is necessary to look for biological processes that are more eco-friendly and economical to recover metals from e-waste. Fungi provide large amounts of organic acids and dissolve metals but using sucrose in the medium is not economical. In this paper, the main objective is to find a suitable alternative carbon substrate instead of sucrose for fungi bioleaching of Ni and Cu in printed circuit boards (PCBs) of mobile phones using Penicillium simplicissimum. Four kinds of carbon sources (including sucrose, cheese whey, sugar, and sugar cane molasses) were selected. Also, pH and...