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optimal-sensor
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Soil Moisture Monitoring in Precision Agriculture Using Estimation Theories
, Ph.D. Dissertation Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
Monitoring of soil moisture plays an essential role in correct decision making and implementation of any closed loop control system in precision agriculture. On the one hand, continuous using of a lot of moisture sensors and monitoring of soil moisture via direct measurement is restricted by practical prohibitions. On the grounds that activation of a lot of sensors continuously requires communication of a large amount of information and causes high power consumption for a moisture monitoring system. On the other hand, using remote sensing methods such as satellite methods, for moisture monitoring in arbitrary spatial and time resolution for control purposes, is not practically possible. The...
Optimal Sensor Location for State Estimation and Monitoring of Gas Transmission Networks
, M.Sc. Thesis Sharif University of Technology ; Bozorgmehry Boozarjomehry, Ramin (Supervisor)
Abstract
Monitoring of natural gas transmission networks, is one of the necessities for efficient, safe, and economical operation of energy supply networks. In order to efficiently control and monitor the operation of gas transmission network, various states of the network (like temperature, pressure, and flow) should be available. Among these states, some can be easily measured, and the rest should be estimated based on these measurements throughout the network. In this project, an algorithm to obtain near optimal locations of various measuring devices has been proposed. Furthermore, a method for estimation of the states of transmission network based on these measurements and Machine Learning has...
Optimal Sensor Locations for Monitoring of Fluid Transmission Networks Using Evolutionary Algorithms
, M.Sc. Thesis Sharif University of Technology ; Bozorgmehry, Ramin (Supervisor)
Abstract
Monitoring of the water transmission networks is an essential factor to regard efficient, safe and economical strategic considerations. Several parameters (fluid pressure, fluid flow and fluid temperature in some cases) are measured to monitor the water transmission networks. The number and location of these measurements in deferent positions affect the cost and quality of the network states monitoring. It is obvious that measuring the all parameters and states of the network is not cost-effective even when it is possible. The conventional sensor-location methods have been developed based on the pressure variation stemmed from a leakage in the network. This study proposes a new procedure to...
Damage Identification in Structures with Lamb Waves and Optimal Sensor Layout Designing
, M.Sc. Thesis Sharif University of Technology ; Abedian, Ali (Supervisor)
Abstract
This study presents the best layout with optimal number of sensors for an arbitrary monitoring area based on reference free damage detection and localization. In recent years, damage detection approaches with the concept of instantaneous baseline measurements in Structural Health Monitoring (SHM) with lamb wave propagation are being developed. An array of spars transducers is obligatory in SHM with lamb wave propagation, so that designing the best one is a concern for many researchers. To obtain the best sensors layout, damage localization process should be done for all definable sensors layouts in many different crack positions. Obviously, doing this seems not practical as wave propagation...
Analysis of Effective Parameters in Localization Accuracy of Positioning Systems
, Ph.D. Dissertation Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Target localization using positioning systems has long been considered by researchers in various fields.One of the important issues in localizing a target is the accuracy of its determined position. There are several parameters in the accuracy of position estimation. In a comprehensive view, these parameters can be divided into three general factors,including the relative geometry of the transmitters/receivers with respect to the target, the accuracy of measurements, and the type of target position estimator.The first factor, i.e. the relative geometry between the target and the transmit/receive antennas, plays an important role in localization accuracy. In the first part of this thesis, the...
Robust controllability assessment and optimal actuator placement in dynamic networks
, Article Systems and Control Letters ; Volume 133 , 2019 ; 01676911 (ISSN) ; Sharif University of Technology
Elsevier B.V
2019
Abstract
This paper presents a new framework for the optimal placement of actuators in uncertain dynamic networks. The objective is to select a subset of nodes from a set of potential actuator placements, such that the controllability of the network with norm-bounded perturbation is preserved over the entire uncertain region. Evaluation of robust controllability is known to be computationally intractable. The recent results of Babazadeh and Nobakhti (2016) are utilized to establish equivalent conditions for robust controllability of uncertain networks. It is shown that for a large class of dynamic systems, including undirected networks, the exact distance to uncontrollability is evaluated by solving...
Reliability-based optimization of an active vibration controller using evolutionary algorithms
, Article Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2017, 26 March 2017 through 29 March 2017 ; Volume 10168 , 2017 ; 0277786X (ISSN); 9781510608214 (ISBN) ; Pourtakdoust, S. H ; Fiberguide Industries; Frontiers Media; OZ Optics, Ltd.; Polytec, Inc.; The Society of Photo-Optical Instrumentation Engineers (SPIE) ; Sharif University of Technology
SPIE
2017
Abstract
Many modern industrialized systems such as aircrafts, rotating turbines, satellite booms, etc. cannot perform their desired tasks accurately if their uninhibited structural vibrations are not controlled properly. Structural health monitoring and online reliability calculations are emerging new means to handle system imposed uncertainties. As stochastic forcing are unavoidable, in most engineering systems, it is often needed to take them into the account for the control design process. In this research, smart material technology is utilized for structural health monitoring and control in order to keep the system in a reliable performance range. In this regard, a reliability-based cost...
Optimal sensors layout design based on reference-free damage localization with lamb wave propagation
, Article Structural Control and Health Monitoring ; Volume 27, Issue 4 , 10 January , 2020 ; Abedian, A ; Nasiri, M ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
This study presents a new approach for designing optimal sensors layout based on accuracy of defect mapping. It is obtained from combination of the reference-free damage detection technique and the probability-based diagnostic imaging method. Considering damage indices based on continuous wavelet transform of sensors signals, the core of this study involves with development of a database of continuous wavelet transform features of a crack. In fact, the database contains the data from 594 different states in crack positions, orientations, and the considered sensing path lengths. Eventually, this database is used for localization of damage by interpolating the stored data collected from the...
Optimal sensor placement for source localization in nlos conditions
, Article 26th Iranian Conference on Electrical Engineering, ICEE 2018, 8 May 2018 through 10 May 2018 ; 2018 , Pages 435-439 ; 9781538649169 (ISBN) ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
The problem of sensor placement for passive source localization under the non-line of sight signal propagation is considered in this paper. To this end, first we derive the Cramer-Rao lower bound for the time of arrival based source localization under non-line of sight conditions. Then, the optimal arrangement of sensors to achieve this lower bound is obtained in the two important cases with all of the receivers being non line of sight ones in the first case and a combination of line of sight and non-line of sight receivers in the 2nd case. © 2018 IEEE
Optimal sensor placement for multi-source AOA localisation with distance-dependent noise model
, Article IET Radar, Sonar and Navigation ; Volume 13, Issue 6 , 2019 , Pages 881-891 ; 17518784 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
In this study, the optimal sensor placement problem for multi-source angle of arrival localisation is investigated. The authors adopt the A-optimality criterion, maximising the trace of Fisher information matrix, to determine the optimal sensor-target geometry under distance-dependent Gaussian noise model. A recursive representation of the Cramer-Rao lower bound is derived to recast the sensor placement problem into a sequential method, obtaining the optimal sensor geometries in a step by step manner. Note that the state-of-the-art methods are highly sensitive to the source location changes such that they should be relocated by any later changes in target geometries, which is practically...
Optimal sensor placement for multi-source AOA localisation with distance-dependent noise model
, Article IET Radar, Sonar and Navigation ; Volume 13, Issue 6 , 2019 , Pages 881-891 ; 17518784 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
In this study, the optimal sensor placement problem for multi-source angle of arrival localisation is investigated. The authors adopt the A-optimality criterion, maximising the trace of Fisher information matrix, to determine the optimal sensor-target geometry under distance-dependent Gaussian noise model. A recursive representation of the Cramer-Rao lower bound is derived to recast the sensor placement problem into a sequential method, obtaining the optimal sensor geometries in a step by step manner. Note that the state-of-the-art methods are highly sensitive to the source location changes such that they should be relocated by any later changes in target geometries, which is practically...
Optimal sensor placement for 2-d range-only target localization in constrained sensor geometry
, Article IEEE Transactions on Signal Processing ; Volume 68 , 2020 , Pages 2316-2327 ; Behnia, F ; Amiri, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Localization of an emitting or reflecting target is one of the most important issues in a wide range of applications including radar, sonar, wireless communication and sensor networks. Due to significant effect on the positioning accuracy, designing the optimal sensor-target geometry has been considered as an important problem in the localization literature. The existing sensor placement methods mainly solve the problem in the cases without any constraints on the sensors locations. In the realistic scenarios, however, the sensors cannot be placed simply in arbitrary locations due to such constraints as the geographical limitations, communication problems between the sensor pairs and the...
Optimal sensor configuration for two dimensional source localization based on TDOA/FDOA measurements
, Article Proceedings International Radar Symposium, 10 May 2016 through 12 May 2016 ; Volume 2016-June , 2016 ; 21555753 (ISSN) ; 9781509025183 (ISBN) ; Adelipour, S ; Behnia, F ; Sharif University of Technology
IEEE Computer Society
2016
Abstract
The Cramer-Rao lower bound for source localization based on Time Difference of Arrival and Frequency Difference of Arrival is investigated in this paper. The result is used for theoretical analysis of optimality in sensor placement. An optimal sensor-target geometry including sensors locations and velocities is presented and its properties is studied
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...
On the optimal performance in asymmetric gaussian wireless sensor networks with fading
, Article IEEE Transactions on Signal Processing ; Volume 58, Issue 4 , 2010 , Pages 2436-2441 ; 1053587X (ISSN) ; Alajaji, F ; Linder, T ; Sharif University of Technology
2010
Abstract
We study the estimation of a Gaussian source by a Gaussian wireless sensor network (WSN) where L distributed sensors transmit noisy observations of the source through a fading Gaussian multiple access channel to a fusion center. In a recent work Gastpar, [ "Uncoded transmission is exactly optimal for a Simple Gaussian Sensor Network", IEEE Trans. Inf. Theory, vol. 54, no. 11, pp. 52475251, Nov. 2008] showed that for a symmetric Gaussian WSN with no fading, uncoded (analog) transmission achieves the optimal performance theoretically attainable (OPTA). In this correspondence, we consider an asymmetric fading WSN in which the sensors have differing noise and transmission powers. We first...
Near-optimal velocity control for mobile charging in wireless rechargeable sensor networks
, Article IEEE Transactions on Mobile Computing ; Volume 15, Issue 7 , 2016 , Pages 1699-1713 ; 15361233 (ISSN) ; Yousefi, H ; Cheng, P ; Chen, J ; Gu, Y. J ; He, T ; Shin, K. G ; Sharif University of Technology
Institute of electrical and electronics engineers Inc
2016
Abstract
Limited energy in each node is the major design constraint in wireless sensor networks (WSNs). To overcome this limit, wireless rechargeable sensor networks (WRSNs) have been proposed and studied extensively over the last few years. In a typical WRSN, batteries in sensor nodes can be replenished by a mobile charger that periodically travels along a certain trajectory in the sensing area. To maximize the charged energy in sensor nodes, one fundamental question is how to control the traveling velocity of the charger. In this paper, we first identify the optimal velocity control as a key design objective of mobile wireless charging in WRSNs. We then formulate the optimal charger velocity...
Malignant tumor detection using linear support vector machine in breast cancer based on new optimization algorithms
, Article Proceedings - 2012 International Symposium on Instrumentation and Measurement, Sensor Network and Automation, IMSNA 2012 ; Volume 1 , 2012 , Pages 80-84 ; 9781467324670 (ISBN) ; Saleh, M.A ; Zabihi, M ; Mohseni, G ; Chomachar, N. A ; Sharif University of Technology
2012
Abstract
Breast cancer is one of the most common fatal diseases in women. Early detection of malignant breast cancer could be a great help in treating this cancer. Many studies have been performed in order to detect the malignant of cancer tumor till now. It has been tried to contribute more in accurate diagnosis of breast cancer by Support Vector Machine, in this paper. LS and SMO methods have been utilized instead of conventional learning method of QP in SVM in this probe. The feasibility of 100 percent in sensitivity for LS-SVM, and 100 percent in specificity for SMO-SVM has been achieved in this assay by the proposed method, which this percentage has not been achieved so far in the previous...
Importance of N-P-N junction in H2S sensing process of SnO2-CuO heterostructures: A theoretical macroscopic approach
, Article IEEE Sensors Journal ; Volume 21, Issue 6 , 2021 , Pages 7123-7129 ; 1530437X (ISSN) ; Ghorbani, M ; Mohammadpour, R ; Moosavi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Metal-oxide gas sensors are widely used for detection of detrimental H2S gas. Among them, SnO2-CuO system has been proved to be an excellent candidate. The previous theoretical 2D thin bilayer model was able to explain some aspects of H2S sensing performance of this promising system. However, experimental researches have indicated that response values for this system are very diverse and various SnO2-CuO multicomponent heterostructures such as rods, wires and particles have much higher response than their thin bilayer counterparts. Understanding the reason behind this differences would help fabrication of optimized sensor element. However, the previous model cannot address this issue mainly...
FPGA-based fast detection with reduced sensor count for a fault-tolerant three-phase converter
, Article IEEE Transactions on Industrial Informatics ; Volume 9, Issue 3 , 2013 , Pages 1343-1350 ; 15513203 (ISSN) ; Philippe, P ; Shahrokh, S ; Mohammad Reza, M. R ; Sharif University of Technology
2013
Abstract
Fast fault detection (FD) and reconfiguration is necessary for fault tolerant power electronic converters in safety critical applications to prevent further damage and to make the continuity of service possible. The aim of this study is to minimize the number of the used additional voltage sensors in a fault tolerant three-phase converter. In this paper, first a practical implementation of a very fast FD scheme with reduced sensor number is discussed. Then, an optimization in this scheme is also presented to decrease the detection time. For FD, special time and voltage criterion are applied to observe the error in the estimated phase-to-phase voltages for a specific period of time. The...
Constrained optimization of sensors trajectories for moving source localization using TDOA and FDOA measurements
, Article International Conference on Robotics and Mechatronics, ICROM 2015, 7 October 2015 through 9 October 2015 ; 2015 , Pages 200-204 ; 9781467372343 (ISBN) ; Hamdollahzadeh, M ; Behnia, F ; Sharif University of Technology
2015
Abstract
This paper examines the problem of determining optimal sensors trajectories for localization of a moving radio source based on Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) measurements in situations in which sensors are constrained both in their movements and regions of operation. By considering the movement of the source and constrained movement of the sensors, a constraint problem is formed which is solved to determine optimal trajectories of the sensors for source tracking. The validity of the proposed algorithm is assessed by two different simulation scenarios and the results verify its proper operation with estimation error decreasing in consecutive steps...