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Passive Source Localization Using Time Difference of Arriaval and Frequency Difference of Arrival Measurements
, M.Sc. Thesis Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Passive source localization accounts for the identification of the position and velocity of an object that emits electromagnetic/sound waves. This concept suggests various civil and military applications such as localization of the cellular phone users for emergency services, navigation, localizing radar and sonar sources. Received Signal Strength (RSS), Time of Arrival (TOA), Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) of the emitted signals are commonly used for position finding. Among all these measurement methods, localization using TDOA and FDOA is highly accurate and needless of any time synchronization between the source and the sensors. Common methods...
Modelling of queue length in freeway work zones – case study karaj-tehran freeway
, Article Promet - Traffic - Traffico ; Volume 33, Issue 1 , 2021 , Pages 49-59 ; 03535320 (ISSN) ; Sharif Ali , S ; Goodarzi, M. J ; Amini, N ; Latifi, H ; Sharif University of Technology
Faculty of Transport and Traffic Engineering
2021
Abstract
In this study, the traffic parameters were collected from three work zones in Iran in order to evaluate the queue length in the work zones. The work zones were observed at peak and non-peak hours. The results showed that abrupt changes in Freeway Free Speed (FFS) and arrival flow rate caused shockwaves and created a bot-tleneck in that section of the freeway. In addition, accel-eration reduction, abrupt change in the shockwave speed, abrupt change in the arrival flow rate and increase in the percentage of heavy vehicles have led to extreme queue lengths and delay. It has been found that using daily traffic data for scheduling the maintenance and rehabilita-tion projects could diminish the...
Investigating the Effect of the Quantum Potential on Particle Behavior in Nonlocal Spacetime and its Role in Solving the Measurement Problem in the Orthodox Quantum
, Ph.D. Dissertation Sharif University of Technology ; Bahrampour, Alireza (Supervisor) ; Golshani, Mehdi (Supervisor)
Abstract
Despite the astonishing successes of quantum mechanics, due to some fundamental problems such as the measurement problem and quantum arrival time problem, the predictions of the theory are in some cases not quite clear and unique. Especially, there are various predictions for the joint spatiotemporal distribution of particle detection events on a screen, which are derived from different formulations and interpretations of the quantum theory. Although the differences are typically small, we show that these predictions can be experimentally distinguished by a proposed unconventional double-slit configuration, which is realizable using present-day single-atom interferometry. Furthermore, we...
Benford's law behavior of internet traffic
, Article Journal of Network and Computer Applications ; Vol. 40, issue. 1 , April , 2014 , p. 194-205 ; Jahangir, A. H ; Sharif University of Technology
Abstract
In this paper, we analyze the Internet traffic from a different point of view based on Benford's law, an empirical law that describes the distribution of leading digits in a collection of numbers met in naturally occurring phenomena. We claim that Benford's law holds for the inter-arrival times of TCP flows in case of normal traffic. Consequently, any type of anomalies affecting TCP flows, including intentional intrusions or unintended faults and network failures in general, can be detected by investigating the first-digit distributions of the inter-arrival times of TCP SYN packets. In this paper we apply our findings to the detection of intentional attacks, and leave other types of...
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...
Deployment of an array of water-cherenkov detectors for extensive air shower experiments
, Article 30th International Cosmic Ray Conference, ICRC 2007, Merida, Yucatan, 3 July 2007 through 11 July 2007 ; Volume 5, Issue HE PART 2 , 2007 , Pages 909-912 ; Bahmanabadi, M ; Khakian Ghomi, M ; Habibi, F ; Samimi, J ; Pezeshkian, Y ; Anvari, A ; Sharif University of Technology
Universidad Nacional Autonoma de Mexico
2007
Abstract
A new small array of cherenkov detectors has been deployed in Tehran, 1200 m above sea level. This array contains of four tanks full of distilled water with diameter of 64 cm and height of 130 cm. The effective area of each tank is about 6.5 × 103cm2 . They are used to detect the air showers and to record the arrival time of the secondary particles. We have collected about 486643 EAS in 5270 h of observation time from Nov-2006 to May-2007. We find zenith and azimuth distribution of EAS with this array. A cosn θ distribution with n = 7.3±0.1 was obtained for zenith angle. Since this tank of distilled water is cheaper and more available than Scintillators it is preferable to use them instead...
Nonlinear cuffless blood pressure estimation of healthy subjects using pulse transit time and arrival time
, Article IEEE Transactions on Instrumentation and Measurement ; Volume 66, Issue 12 , 2017 , Pages 3299-3308 ; 00189456 (ISSN) ; Kachuee, M ; Shabany, M ; Sharif University of Technology
Abstract
This paper presents a novel blood pressure (BP) estimation method based on pulse transit time (PTT) and pulse arrival time (PAT) to estimate the systolic BP (SBP) and the diastolic BP (DBP). A data acquisition hardware is designed for high-resolution sampling of phonocardiogram (PCG), photoplethysmogram, and electrocardiogram (ECG). PCG and ECG perform as the proximal timing reference to obtain PTT and PAT indices, respectively. In order to derive a BP estimator model, a calibration procedure, including a supervised physical exercise, is conducted for each individual, which causes changes in their BP, and then, a number of reference BPs are measured alongside the acquisition of the signals...
Non-invasive blood pressure estimation using phonocardiogram
, Article Proceedings - IEEE International Symposium on Circuits and Systems, 28 May 2017 through 31 May 2017 ; 2017 ; 02714310 (ISSN) ; 9781467368520 (ISBN) ; Kachuee, M ; Shabany, M ; Sharif University of Technology
Abstract
This paper presents a novel approach based on pulse transit time (PTT) for the estimation of blood pressure (BP). In order to achieve this goal, a data acquisition hardware is designed for high-resolution sampling of phonocardiogram (PCG) and photoplethysmogram (PPG). These two signals can derive PTT values. Meanwhile, a force-sensing resistor (FSR) is placed under the cuff of the BP reference device to mark the moments of measurements accurately via recording instantaneous cuff pressure. For deriving the PTT-BP models, a calibration procedure including a supervised physical exercise is conducted for each individual. The proposed method is evaluated on 24 subjects. The final results prove...
Non-invasive and Continuous Blood Pressure Measurement Using Pulse Transit Time without Cuff Requirement
, M.Sc. Thesis Sharif University of Technology ; Shabany, Mahdi (Supervisor)
Abstract
This thesis addresses cuff-less blood pressure (BP) estimation, for systolic blood pressure (SBP) and diastolic blood pressure (DBP) estimation with the aid of the processing of vital signals. Both with and without calibration per person approaches for BP estimation are considered. A data acquisition hardware is designed for high-resolution sampling of phonocardiogram (PCG), Photoplethysmogram (PPG) and electrocardiogram (ECG). Using these signals, pulse transit time (PTT) and pulse arrival time (PAT) indexes, which would be used for BP estimation with calibration, are extracted. For the BP estimator model using the calibration, A nonlinear model based on PTT or PAT, via modeling the vessels...
Hardware Implementation of Wearable Cuff-less Blood Pressure Monitoring Module
,
M.Sc. Thesis
Sharif University of Technology
;
Shabany, Mahdi
(Supervisor)
;
Mohammadzade, Hoda
(Supervisor)
Abstract
Hypertension precvalence is 24 and 20.5 percent in men and women, respectively. Continuous Blood Pressure monitoring can provide invaluable information about individuals’ health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This work presents an efficient algorithm, based on the Pulse Arrival Time (PAT), extracted from Electrocardiogram (ECG) and Photopletysmograph (PPG), for the continuous and cuff-less estimation of the Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), and Mean Arterial Pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital...
Urban Traffic Analysis Using Limited Queries from a Predicting Source
, M.Sc. Thesis Sharif University of Technology ; Abam, Mohammad Ali (Supervisor)
Abstract
In local transportation service companies, there is a need for estimation of arrival times (ETA) for customers. These companies not having the sufficient number of active online users, they are not able to obtain a proper estimation for ETA from that data. However, there are some overseas companies that have the established user base, and provide access to necessary data with a service fee. It is possible to solve this problem using the data which they provide.In this thesis, the problem of learning a hidden graph for the purpose of aiding local companies is explained and different aspects of it are introduced. In order to tackle this problem, first we define the idea of vertex separators,...
DiskAccel: Accelerating disk-based experiments by representative sampling
, Article Performance Evaluation Review, 15 June 2015 through 19 June 2015 ; Volume 43, Issue 1 , 2015 , Pages 297-308 ; 01635999 (ISSN) ; Asadi, H ; Sarbazi Azad, H ; Sharif University of Technology
Association for Computing Machinery
2015
Abstract
Disk traces are typically used to analyze real-life workloads and for replay-based evaluations. This approach benefits from capturing important details such as varying behavior patterns, bursty activity, and diurnal patterns of system activity, which are often missing from the behavior of workload synthesis tools. However, accurate capture of such details requires recording traces containing long durations of system activity, which are difficult to use for replay-based evaluation. One way of solving the problem of long storage trace duration is the use of disk simulators. While publicly available disk simulators can greatly accelerate experiments, they have not kept up with technological...
Joint time difference of arrival/angle of arrival position finding in passive radar
, Article IET Radar, Sonar and Navigation ; Volume 3, Issue 2 , 2009 , Pages 167-176 ; 17518784 (ISSN) ; Derakhshani, M ; Sharif University of Technology
2009
Abstract
Several target position finding methods are proposed in various papers mainly regarding sensor networks. However, the problem of position finding in passive radar systems is somewhat different from the general case of sensor networks. Generally, in a passive radar system, there are few receivers located at short distances when compared with the it distance from the target. In this case, a problem known as geometric dilution of precision (GDP) occurs, which considerably increases the error of many proposed methods. This phenomenon can even make the position finding equations non-solvable. Regarding this fact, we have developed a least mean square error (LMSE) based method, which uses both the...
A new scheduling strategy for aircraft landings under dynamic position shifting
, Article 2008 IEEE Aerospace Conference, AC, Big Sky, MT, 1 March 2008 through 8 March 2008 ; 2008 ; 1095323X (ISSN) ; 1424414881 (ISBN); 9781424414888 (ISBN) ; Naderi, E ; Sharif University of Technology
2008
Abstract
Optimal scheduling of runway operations plays an important role in improving safety and efficiency of any congested airspace. The objective of scheduling is runway assignment and computing arrival times that minimize delays and maximize runway throughput. Currently, methods for runway scheduling are categorized into First-Come-First-Serve (FCFS) and Constrained Position Shifting (CPS). In this work, we describe a new algorithm for real time scheduling for single as well as multiple parallel runway scheduling. The new approach is comparable to FCFS algorithms in accommodating practical issues while enjoying optimality similar to that of CPS methods. Different case studies show that the new...
Optimal geometry analysis for tdoa-based localization under communication constraints
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 57, Issue 5 , 2021 , Pages 3096-3106 ; 00189251 (ISSN) ; Behnia, F ; Amiri, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
The sensor-source geometry has a significant effect on accuracy of source localization problems. In a sensor placement problem, one attempts to optimally place the sensors in the surveillance area so as to optimize a performance criterion. Sensor placement methods mainly solve the associated problems without taking any specific constraint on permissible location of sensors into account. In practical applications, however, possible location for deployment of the sensors are subject to such limitations as environmental, industrial, and communication constraints, which affects the optimal sensor-source geometry. In this article, we consider the problem of optimal sensor placement, based on time...
Cuffless blood pressure estimation algorithms for continuous health-care monitoring
, Article IEEE Transactions on Biomedical Engineering ; Volume 64, Issue 4 , 2017 , Pages 859-869 ; 00189294 (ISSN) ; Kiani, M. M ; Mohammadzade, H ; Shabany, M ; Sharif University of Technology
IEEE Computer Society
2017
Abstract
Goal: Continuous blood pressure (BP) monitoring can provide invaluable information about individuals' health conditions. However, BP is conventionally measured using inconvenient cuff-based instruments, which prevents continuous BP monitoring. This paper presents an efficient algorithm, based on the pulse arrival time (PAT), for the continuous and cuffless estimation of the systolic BP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) values. Methods: The proposed framework estimates the BP values through processing vital signals and extracting two types of features, which are based on either physiological parameters or whole-based representation of vital signals. Finally,...
Train timetabling on double track and multiple station capacity railway with useful upper and lower bounds
, Article Scientia Iranica ; Volume 24, Issue 6 , 2017 , Pages 3324-3344 ; 10263098 (ISSN) ; Eshghi, K ; Sharif University of Technology
Abstract
Train scheduling has been one of the significant issues in the railway industry in recent years since it has an important role in efficacy of railway infrastructure. In this paper, the timetabling problem of a multiple-tracked railway network is discussed. More specifically, a general model is presented here in which a set of operational and safety requirements is considered. The model handles the trains overtaking in stations and considers the stations' capacity. The objective function is to minimize the total travel time. Unfortunately, the problem is NP-hard, and real-sized problems cannot be solved in an acceptable amount of time. In order to reduce the processing time, we presented some...
Reliability-based network flow estimation with day-to-day variation: a model validation on real large-scale urban networks
, Article Journal of Intelligent Transportation Systems: Technology, Planning, and Operations ; Volume 22, Issue 2 , 2018 , Pages 121-143 ; 15472450 (ISSN) ; Mirjafari, P. S ; Poorzahedy, H ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
Day-to-day variation in the travel times of congested urban transportation networks is a frustrating phenomenon to the users of these networks. These users look pessimistically at the path travel times, and learn to spend additional time to safeguard against serious penalties that await late arrivals at the destinations. These additional expenses are charges similar to the tolls in system equilibrium flow problem, but may not be collected. With this conjecture, the user equilibrium (UE) formulation of congested network flow problem would lack some necessary factors in addressing appropriate path choices. This study, following a previous work proposing pessimistic UE (PUE) flow, aims to show...