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    The addition of data aggregation to SPEED routing algorithm while keeping the functionality of available techniques

    , Article 2nd International Conference on Future Networks, ICFN 2010, 22 January 2010 through 24 January 2010 ; January , 2010 , Pages 349-353 ; 9780769539409 (ISBN) Roustaei, R ; Yousefi Fakhr, F ; Movaghar, A ; Sharif University of Technology
    2010
    Abstract
    Data aggregation is a technique that is used to decrease extra and repetitive data in cluster based routing protocols. As we know SPEED routing algorithm is based on service quality and dose not perform data aggregation. In this article, we try to add an data aggregation technique to the available techniques without interfering with the functions of previous ones. The idea involves virtual configuration of sensors and specification of an individual ID to the created data by the sensors in each region, then data aggregation in relay node is done by this ID, resulting in less energy consumption, lower traffic and repeated data, an increase in network lifetime and better quality of service  

    Cooperative Data Aggregation in Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Mehrabi Koushki, Masoud (Author) ; Movaghar, Ali (Supervisor)
    Abstract
    Minimizing energy consumption is the most important concern in wireless sensor networks (WSNs). Cooperative multiple-input multiple-output (MIMO) and data aggregation are two promising techniques to conserve energy in network nodes by coordinating their transmissions through cooperative communications along with eliminating the inherent redundancy of raw data for transmissions. In this thesis, with the goal of reducing energy consumption, we present a dynamic clustering framework for combined used of cooperative MIMO and data aggregation in cluster-based WSNs. We derive a new and more general energy model for computing energy consumption of cooperative data aggregation in wireless sensor... 

    An efficient secure scheme for lossy and lossless data aggregation in smart grid

    , Article 9th International Symposium on Telecommunication, IST 2018, 17 December 2018 through 19 December 2018 ; 2019 , Pages 528-534 ; 9781538682746 (ISBN) Sarenche, R ; Forghani, P ; Ameri, M. H ; Aref, M. R ; Salmasizadeh, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    In this paper, we propose an efficient secure data aggregation scheme for the smart grid, which supports both lossy and lossless data aggregation. In order to reduce the computational overhead of the control center, our proposed model includes a number of entities, called gateways, which act as intermediaries between the users and the control center. At the end of each measurement interval, each user generates a report which is encrypted using the Paillier cryptosystem and contains the user's consumption amount during the previous measurement interval as well as his or her prediction of consumption during another interval in the future. After receiving the user's reports, gateways perform... 

    Semantic data gathering of physical entities in semantic sensor networks using software agents

    , Article Information Technology and Control ; Volume 47, Issue 2 , 2018 , Pages 167-183 ; 1392124X (ISSN) Ahmadinia, M ; Movaghar, A ; Rahmani, A. M ; Sharif University of Technology
    Kauno Technologijos Universitetas  2018
    Abstract
    In a wireless sensor network, with numerous sensor nodes, a huge volume of data is produced. For the massive data generated by sensor networks to be understood by the machine, semantic web technologies such as ontology need to be applied. On the other hand, since the end users intend to access the high-level physical entities information monitored by the sensor network, the applicability of sensor networks can be enhanced through proposing a strategy to extract the data based on entities instead of extracting the raw sensor data. Hence, in this paper firstly, ontology will be presented for physical entities semantic modelling (PESM). Secondly, an appropriate strategy will be offered to... 

    A new approach to improve quality of service in SPEED routing protocol in wireless sensor network through data aggregation

    , Article 2nd International Conference on Environmental and Computer Science, ICECS 2009, 28 December 2009 through 30 December 2009 ; 2009 , Pages 393-397 ; 9780769539379 (ISBN) Roustaei, R ; Zohrevandi, E ; Hassani, K ; Movaghar, A ; Sharif University of Technology
    Abstract
    SPEED routing algorithm is a service quality based algorithm in which data aggregation dose not happen. In this article, data aggregation has been added to the conventional technique in SPEED algorithm. The idea involves virtual configuration of sensors and specification of an individual ID to the created data by the sensors in each region, then data aggregation in relay node is done by this ID, resulting in less energy consumption, lower traffic and repeated data, an increase in network lifetime and better quality of service. © 2009 IEEE  

    A secure ECC-based privacy preserving data aggregation scheme for smart grids

    , Article Computer Networks ; Volume 129 , 2017 , Pages 28-36 ; 13891286 (ISSN) Vahedi, E ; Bayat, M ; Pakravan, M. R ; Aref, M. R ; Sharif University of Technology
    Abstract
    Development of Smart Grid and deployment of smart meters in large scale has raised a lot of concerns regarding customers’ privacy. Consequently, several schemes have been proposed to overcome the above mentioned issue. These schemes mainly rely on data aggregation as a method of protecting users’ privacy from the grid operators. However, the main problem with most of these schemes is the fact that they require a large amount of processing power at the meter side. This, together with the fact that smart meters don't usually have a powerful processor, can cause the unavailability of smart meter data at the required time for operators of the grid, and at the same time prevents smart meters from... 

    Real-time Data Aggregationin Wireless Sensor Networks

    , Ph.D. Dissertation Sharif University of Technology Yousefi, Hamed (Author) ; Movaghar Rahimabadi, Ali (Supervisor)
    Abstract
    Recent advancements in wireless communications and also a tendency to use low cost, tiny, and autonomous high performance products have led to the emergence of wireless sensor networks (WSNs). As the main source of power in a sensor node is a limited and irreplaceable battery, energy is the main important issue. Data aggregation, as an in-network processing method, is a promised technique aiming to conserve energy by reducing the number of packet transmissions through the network. It is a key, yet time-consuming functionality in WSNS, where we hold packets in intermediate nodes to promote aggregation efficiency. However, the requirement of real-time communications is becoming more and more... 

    Preserving Privacy in Smart Grid

    , M.Sc. Thesis Sharif University of Technology Vahedi, Erfaneh (Author) ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Co-Advisor)
    Abstract
    Development of Smart Grid and deployment of smart meters in large scale has raised a lot of concerns regarding customers’ privacy. Consequently, several schemes have been proposed to overcome the above mentioned issue. These schemes mainly rely on data aggregation as a method of protecting users’ privacy from the grid operators. However, the main problem with most of these schemes is the fact that they require a large amount of processing power at the meter side. This, together with the fact that smart meters don’t usually have a powerful processor, can cause the unavailability of smart meter data at the required time for operators of the grid, and at the same time disables smart meters from... 

    Enhancement of Energy Consumption of Real-Time Wireless Sensor Networks by Data Aggregation Techniques

    , M.Sc. Thesis Sharif University of Technology Mahmoudifard, Mehdi (Author) ; Jahangir, Amir Hossein (Supervisor)
    Abstract
    Prolonging the lifetime of wireless sensor networks (WSN) is one of the most important goals in the sensor network research. A lot of work has been done to achieve this goal. Since sensor nodes normally have limited resources in terms of energy, bandwidth and computation capability, efficiency is a key design goal in sensor network research. Data aggregation is a very important method to conserve energy by eliminating the inherent redundancy of raw data in dense WSNs. Previous research on data aggregation has demonstrated its effectiveness in reducing traffic, easing congestion and decreasing the energy consumption. However, few are actually designed for a real world application and... 

    Efficient Method for Data Aggregation for K-coverage in Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Movaffagh, Ali (Author) ; Hemmatyar, Ali Mohammad Afshin (Supervisor)
    Abstract
    Technology advances in the era of wireless communications leads to the birth of a very useful network called Wireless sensor Network which is very interesting for scientists and researchers. While these networks consist of tens to thousands of tiny sensor nodes, they consume their energy from none-rechargeable batteries. Reducing energy consumption and extend the life of network is the most challenging requirement for these kinds of networks; in some environments like military training which precision and sensitivity are critical, it might take at least K sensors to cover the whole area and these conditions leads to a vast data repetition in network and as a result energy exhaustions in... 

    Energy-Aware Routings in Cognitive Wireless Sensor Network

    , M.Sc. Thesis Sharif University of Technology Zarrinpour, Mehdi (Author) ; Hemmatyar, Ali Mohammad Afshin (Supervisor)
    Abstract
    Wireless Sensor Networks (WSNs) has been a research topic for more than a decade, and the range of potential applications has spanned beyond the military domain into commercial domains. A key feature of current WSN solutions is operation in unlicensed frequency bands, for instance, the worldwide available 2.4 GHz band. However, the same band is shared by other wireless applications, such as Wi-Fi and Bluetooth, as well as other proprietary technologies. There is evidence that unlicensed spectrum is becoming overcrowded, to solve this problem, concept of cognitive radio has been introduced.
    A main challenge for routing in cognitive radio wireless sensor networks is the collaboration... 

    Energy-Efficient Reliable Data Aggregation in Wireless Sensor Neworks

    , M.Sc. Thesis Sharif University of Technology Ashouri, Majid (Author) ; Hemmatyar, Ali Mohammad Afshin (Supervisor)
    Abstract
    Data aggregation is an efficient method to conserve energy by reducing packet transmissions in Wireless Sensor Networks. However, providing end-to-end data reliability is a major challenge when the network uses data aggregation. In this case a packet loss can miss a complete subtree of values, so greatly affect final results. Data transmission in multiple paths can tolerate this problem, but it may incur some computational error for duplicate-sensitive aggregates when aggregating individual sensor values multiple times. In this thesis, we have proposed a reliable data Aggregation protocol which uses the available path redundancy to deliver a correct aggregate result to the sink with a high... 

    Fault Diagnosis of Rotating Machinery using Multi-Sensor Data

    , M.Sc. Thesis Sharif University of Technology Hekmat Golmakani, Saeed (Author) ; Arghand, Hesamoddin (Supervisor) ; Behzad, Mehdi (Supervisor)
    Abstract
    Vibration signals have been used for fault diagnosis frequently. These signals are captured using sensors, which are mounted on different locations of the equipment. Using data captured from different locations of the equipment, will result in roubustness of the fault diagnosis model. But sometimes the predictions of sensors mounted on different locations, happen to conflict. These conflicts among sources of information, make it hard to decide about the overal health state of the equipment. In fact, these conflicts causes a kind of uncertainty called epistemic uncertainty. A powerful mathematical framework for managing epistemic uncertainties, is Dempster-Shafer theory of evidence. An... 

    Data Reduction and Aggregation in Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Rooshenas Amir Mohammad (Author) ; Movaghar Rahimabadi, Ali (Supervisor)
    Abstract
    Data transmission consumes most of the power resources in wireless sensor networks. Con-sequently, a large number of methods have been devised to cope with this problem. In this thesis, we propose a data reduction algorithm based on the transmission workload of interme-diate nodes. We aggregate the incoming packets to the intermediate nodes into one packet by employ ing the Principal Component Analysis (PCA). Therefore, each intermediate node only sends one packet in stead of relaying all the incoming packets and hence we achieve consid-erable reduction in power consumption at those nodes. Although this approach imposes some delay for buffering the incoming packets, but extending the... 

    Fast aggregation scheduling in wireless sensor networks

    , Article IEEE Transactions on Wireless Communications ; Volume 14, Issue 6 , 2015 , Pages 3402-3414 ; 15361276 (ISSN) Yousefi, H ; Malekimajd, M ; Ashouri, M ; Movaghar, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    Data aggregation is a key, yet time-consuming functionality introduced to conserve energy in wireless sensor networks (WSNs). In this paper, to minimize time latency, we focus on aggregation scheduling problem and propose an efficient distributed algorithm that generates a collision-free schedule with the least number of time slots. In contrast to others, our approach named FAST mainly contributes to both tree construction, where the former studies employ Connected 2-hop Dominating Sets, and aggregation scheduling that was previously addressed through the Competitor Sets computation. We prove that the latency of FAST under the protocol interference model is upper-bounded by 12R+Δ-2, where R... 

    NSSSD: A new semantic hierarchical storage for sensor data

    , Article 20th IEEE International Conference on Computer Supported Cooperative Work in Design, 4 May 2016 through 6 May 2016 ; 2016 , Pages 174-179 ; 9781509019151 (ISBN) Gheisari, M ; Movassagh, A. A ; Qin, Y ; Yong, J ; Tao, X ; Zhang, J ; Shen, H ; Liu, X. P ; Yong, J ; Barthes, J. P ; Shen, W ; Yang, C ; Luo, J ; Chen, L ; IEEE Systems, Man, and Cybernetics Society; International Working Group on Computer Supported Cooperative Work in Design (CSCWD) ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    Abstract
    Sensor networks usually generate mass of data, which if not structured for future applications, will require much effort on analytical processing and interpretations. Thus, storing sensor data in an effective and structured format is a key issue in the area of sensor networks. In the meantime, even a little improvement on data storing structure may lead to a significant effect on the lifetime and performance of the sensor network. This paper describes a new method for sensor storage that combines semantic web concepts, a data aggregation method along with aligning sensors in hierarchical form. This solution is able to reduce the amount of data stored at the sink nodes significantly. At the... 

    An Effective Data Aggregation Mechanism in Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Marvi, Mona (Author) ; Jahangir, Amir Hossein (Supervisor)
    Abstract
    Wireless sensor networks (WSNs) are tiny devices with limited computation and power supply. For such devices, data transmission is a very energy-consuming operation. Data aggregation eliminates redundancy and minimizes the number of transmissions in order to save energy. This research explores the efficiency of data aggregation by focusing on different aspects of the problem such as energy efficiency, latency and accuracy. To achieve this goal, we first investigate data aggregation efficiency with constraint on delay, which can be compatible with other important system properties such as energy consumption and accuracy. By simulation, we will show that, depending on the application, we can... 

    Resource Management in Query-Driven Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Bahrami, Somaieh (Author) ; Movaghar Rahimabadi, Ali (Supervisor)
    Abstract
    Wireless sensor network is composed of a large number of sensor nodes which are densely deployed to monitor the environment and collect information from physical events. There are different modelsfor sending collected data to users; one of them is query-driven models, in which according to user interest and via declarative queries collected data is delivered. Wireless sensor networks are energy constrained; regarding this issue, it is necessary to have an energy efficient design. Data aggregation or in network processing is one existing solution to reduce energy consumption. Data correlation or redundancy is also can be used with this method to save energy even more. In this thesis, an... 

    Design and Implementation of an Intention-based Control System for a Lower Limb Exoskeleton by Combining Biological, Kinematic and Interaction Force Signals

    , M.Sc. Thesis Sharif University of Technology Salarkia, Morteza (Author) ; Vosoughi, Gholamreza (Supervisor)
    Abstract
    The goal of this project is to propose an algorithm to detect human motion intent during level walking. The primary aim of this algorithm should be to reduce human-robot interaction forces by combining EMG and force signals. Human gait is composed of 6 different stages. During each stage, each muscle is activated differently so it is possible to detect human intent by a pattern recognition technique. However, due to the fact that EMG signals are unrepeatable and noisy, we propose that combining EMG, motion and interaction force signals may lead to more concise and repeatable estimates of human motion intent. As a result, this control approach is expected to reduce human robot interaction... 

    Multi-omic Single-cell Data Integration Using Deep Neural Networks

    , M.Sc. Thesis Sharif University of Technology Omidi, Alireza (Author) ; Sharifi Zarchi, Ali (Supervisor)
    Abstract
    The advent and advance of single-cell technologies have enabled us to measure the cell function and identity by using different assays and viewing it by different technologies. Nowadays, we are able to measure multiple feature vectors from same- single cells from multiple abstract molecular levels (genome, transcriptome, proteome, ...) simultaneously. Hence, the analysts can view the cell from different yet correlated angles and study their behaviours. Such progress in joint single-cell assessments plus the development and spread of more common single-cell assays - that measure one feature vector per cell - caused the growing need for computational tools to integrate these datasets in order...