Loading...
Search for:
sensor-networks
0.009 seconds
Total 325 records
Ontology-based modelling and information extracting of physical entities in semantic sensor networks
, Article IETE Journal of Research ; 2018 , Pages 1-17 ; 03772063 (ISSN) ; Movaghar, A ; Rahmani, A. M ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
The semantic sensor web adds semantic web technologies such as ontology to sensor network. Semantic technologies can help the better management of query and data aggregation of the sensor network. So far, several ontologies have been presented for the semantic presentation of sensor networks concepts. However, applications and end-users require physical entities information rather than technical details and information regarding sensors and sensor network. This paper semantically models physical entities whose information is collected by sensor networks at a level higher than sensors and their observations. Hence, first, an ontology is presented for semantically modelling physical entities...
Improvement of fault detection in wireless sensor networks
, Article 2009 Second ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM 2009, Sanya, 8 August 2009 through 9 August 2009 ; Volume 4 , 2009 , Pages 644-646 ; 9781424442461 (ISBN) ; Barati, A ; Movaghar, A ; Yangzhou University; Guangdong University of Business Studies; Wuhan Institute of Technology; IEEE SMC TC on Education Technology and Training; IEEE Technology Management Council ; Sharif University of Technology
2009
Abstract
This paper presents a centralized fault detection algorithm for wireless sensor networks. Faulty sensor nodes are identified based on comparisons between neighboring nodes and own central node and dissemination of the decision made at each node. RNS system is used to tolerate transient faults in sensing and communication. In this system, arithmetic operations act on residues - reminder of dividing original number in several definite modules - in parallel. Consequently computations on these residues which are smaller than the original number are performed, so speed up arithmetic and decreased power consumption is achieved. ©2009 IEEE
Modeling and evaluating reliable real-time degree in multi-hop wireless sensor networks
, Article 2009 IEEE Sarnoff Symposium, SARNOFF 2009, Princeton, NJ, 30 March 2009 through 1 April 2009 ; 2009 ; 9781424433827 (ISBN) ; Yousefi, H ; Jahangir, A. H ; IEEE ; Sharif University of Technology
2009
Abstract
Wireless Sensor Network (WSN) should be capable of fulfilling its mission, in a timely manner and without loss of important information. In this paper, we propose a new analytical model for calculating RRT (Reliable Real-Time) degree in multihop WSNs, where RRT degree describes the percentage of real-time data that the network can reliably deliver on time from any source to its destination. Also, packet loss probability is modeled as a function of the probability of link failure when the buffer is full and the probability of node failure when node's energy is depleted. Most of network properties are considered as random variables and a queuing-theory based model is derived. In this model,...
A new adaptive prediction-based tracking scheme for wireless sensor networks
, Article Proceedings of the 7th Annual Communication Networks and Services Research Conference, CNSR 2009, 11 May 2009 through 13 May 2009, Moncton, NB ; 2009 , Pages 335-341 ; 9780769536491 (ISBN) ; Abolhassani, B ; Abdizadeh, M. T ; Sharif University of Technology
2009
Abstract
The accuracy of the object tracking is dependent on the tracking time interval. Smaller tracking time interval increases the accuracy of tracking a moving object. However, this increases the power consumption significantly. This paper proposes a new adaptive algorithm (AEC) to adapt tracking time interval such that it minimizes power consumption while keeping the required accuracy. Simulation results show that using the proposed algorithm, the tracking network has a good performance with the added advantage of reducing the power consumption significantly when compared with existing nonadaptive methods (like PATES). Moreover, simulation results show that the performance of the proposed...
MEHR: multi-hop energy-aware hierarchical routing for wireless sensor networks
, Article Proceedings of New Technologies, Mobility and Security Conference and Workshops, NTMS 2008, 5 November 2008 through 7 November 2008, Tangier ; 2008 ; 9782953244304 (ISBN) ; Movaghar, A ; Sharif University of Technology
2008
Abstract
Nowadays, wireless sensor networks are known as a new challenge in network science. New features of these networks have made it impossible to use the traditional routing protocols. The most important challenge of these networks is the limited energy of nodes. In this paper, we will introduce MEHR as a multi-hop location-unaware hierarchical routing protocol to decrease the energy consumption in nodes, and to increase the network lifetime, we also apply MEHR to reach to a scalable routing. We will introduce a new factor to select candidate nodes and to send intra-cluster messages. We will use place-advertisement messages of sink, and a limiting parameter and also overhearing concept to create...
Energy adaptive cluster-head selection for wireless sensor networks using center of energy mass
, Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 130-137 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) ; Manzuri Shalmani, M. T ; Sharif University of Technology
2008
Abstract
A set of small battery-operated sensors with low-power transceivers that can automatically form a network and collect some desired physical characteristics of the environment is called a wireless sensor network. The communications must be designed to conserve the limited energy resources of the sensors [14].By clustering sensors we can save energy. In this paper, we introduce a new concept called "Center of Energy Mass" which is a combination of both energy level and location of the nodes which is used to form the new factor of "distance of the nodes to the CEM ".Distance of the nodes to the CEM is used together with Probability Density Function of the normal distribution in optimizing...
Survivability modeling of wireless sensor networks
, Article 2008 IEEE International Symposium on Wireless Communication Systems, ISWCS'08, ReykjavIk, 21 October 2008 through 24 October 2008 ; 2008 , Pages 593-597 ; 9781424424894 (ISBN) ; Jahangir, A. H ; Taghikhaki, Z ; Masoum, A ; Sharif University of Technology
2008
Abstract
Network survivability is one of the main design challenges in wireless sensor networks (WSN). Survivability is the ability of the network to provide essential services in the presence of attacks and/or failures, and recover full service in a timely manner. To the best knowledge of us, survivability for WSN has never been studied considering failure effects on network. We consider the network survivability as a composite measure consisting of both network failure duration and failure impact on the network. In this paper we model network survivability in steady state. In this state, network is affected by predicted failures. This modeling is based on network connectivity and coverage, when an...
A quantitative real-time model for multihop wireless sensor networks
, Article 2007 3th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, ISSNIP, Melbourne, VIC, 3 December 2007 through 6 December 2007 ; 2007 , Pages 79-84 ; 1424415020 (ISBN); 9781424415021 (ISBN) ; Jahangir, A. H ; Sharif University of Technology
2007
Abstract
Wireless Sensor Network (WSN) should be capable of fulfilling its mission, in a timely manner. Therefore, we propose a quantitative real-time model for multihop WSN. "Real-time degree" describes the percentage of real-time data that the network can deliver on time from any source to its destination. Most of network properties are considered as random variables and a queuing-theory based model is derived. In this model, the effect of network load on the packets ' delay and the "real-timeliness" of the network are considered. Simulation results are used to validate the proposed model. The simulation results agree very well with the model. © 2007 IEEE
Improving Packet Scheduling in Multpath Video Delivery Over Wireless Multimedia Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Akbari, Behzad (Supervisor)
Abstract
Recent advances in WSN have led to next generation of it for multimedia transmission which is WMSN. WMSN has several applications like environmental monitoring, advance health care delivery and etc. However, providing QoS requirements of transmitting video data like delay, bandwidth and packet loss with minimum distortion at perceived video quality over WMSN with resource constraints is a challenging problem. Using multipath routing protocol for video communication can increase bandwidth and decrease delay over WMSN. Moreover, all video packets have not the same effect on video distortion. We propose a scheduling mechanism which classifies packets according to their types and contents and...
Distributed Compressed Sensing (DCS) and its Application in Wireless Sensor Network (WSN)
, M.Sc. Thesis Sharif University of Technology ; Babaei Zadeh, Masoud (Supervisor)
Abstract
Recent advances in Micro-Electro-Mechanical Systems (MEMS) technology, wireless communications,and digital electronics have enabled the development of low-cost, low-power,multifunctional sensor nodes that are small in size and communicate untethered in short distances.Wireless Sensor Network (WSN) including these sensors has been utilized in many applications, namely military and environmental applications. Due to unchangeable battery in most WSNs, Power consumption is an important challenge in such systems. A sensor node expends maximum energy in data communication. Control environmental parameter is among the most important applications of WSN. The actual physical environmental information...
Real-time Data Aggregationin Wireless Sensor Networks
, Ph.D. Dissertation Sharif University of Technology ; 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...
A Rate Control Mechanism for Wireless Multimedia Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Khansari, Mohammad (Supervisor) ; Akbari, Behzad (Co-Advisor)
Abstract
To make Wireless Multimedia Sensor Networks (WMSNs) more practical, researchers have tried to meet its challenges in the last decade. Some factors of WMSNs, such as low bandwidth and channel errors, cause a decrease in the video quality that is declared as distortion. On the other hand, one important requirement in the context of multimedia streaming is its quality. In this thesis, we first introduce and use an adaptive cross-layer error control in the link layer, and then we implement a new cross-layer source rate control Mechanism for efficient and reliable real-time multimedia streaming in wireless sensor networks. Our main objective is to minimize distortion. Some of the used cross-layer...
Low-latency Beacon Scheduling for Two-way Transmission in ZigBee Tree Based Wireless Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Manzuri Shalmani, Mohammad Taghi (Supervisor)
Abstract
Nowadays, Wireless Sensor Networks (WSNs) play a role in the field of information technology for data gathering purposes. In general, each WSN contains many inexpensive wireless nodes, each capable of collecting, processing, and storing environmental information, and communicating with neighboring nodes. WSNs have been successfully used in different applications such as object tracking, emergency guiding, and environment monitoring. The popular WSN platforms in real-world applications are MICAz, Tmote , and Dust Network. Two standards, namely the ZigBee and IEEE 802.15.4 standards are projected to provide interoperability of different platforms, and to define physical, MAC, and network...
Intrusion Detection in Wireless Sensor Networks Using Incremental Emotional Intelligence Models
, M.Sc. Thesis Sharif University of Technology ; Hashemi Mohammad Abad, Saeid (Supervisor)
Abstract
Wireless Sensor Networks (WSNs) are rapidly emerging as an important area in mobile computing research. Applications of WSNs are numerous and growing, some of them are even highly critical, like military or safety applications. Security measures must be applied to protect the network from a variety of attacks. Since no intrusion prevention measure is perfect, intrusion detection becomes an important second wall to protect the network. WSNs have unique nature which is different from other kinds of networks. In this project, we examine the characteristics and vulnerabilities of WSNs and propose a new intrusion detection model to protect the network security. In this work we have not only...
QoS Management Traffic and Congestion Control in WSNs
, M.Sc. Thesis Sharif University of Technology ; Manzuri Shalmani, Mohammad Taghi (Supervisor)
Abstract
Congestion in Wireless Sensor Networks (WSNs) leads to both packet loss and excessive energy consumption. That is why congestion has to be controlled during the life of a WSN. One of the go well protocols that has tried to tackle congestion in WSNs is PCCP. PCCP utilizes a cross-layer optimization, imposes a hop-by-hop approach and achieves efficient congestion control; however it has got its own shortcomings. Here we have carried out a survey on congestion problem and have proposed a solution called Modified PCCP to elevate the performance of PCCP by making some changes in the scheduler which is designed in the cross layer. Using this model the congestion is controlled and the PCCP protocol...
Using Learning Algorithms for Energy Efficient Routing in Wireless Sensor Network
, M.Sc. Thesis Sharif University of Technology ; Beigy, Hamid (Supervisor)
Abstract
Wireless Sensor Networks (WSNs) have attracted much attention in recent years for their unique characteristics and wide use in many different applications. WSNs are composed of many tiny sensor nodes that have limitations on energy level, bandwidth, processing power and memory. Therefore, reducing energy consumption and the increased network lifetime and scalability are the main routing challenges in sensor networks. Many algorithms were presented for routing in sensor networks; a class of theses algorithms is hierarchical algorithms based on clustering. Their main goals are to reduce energy consumption, distribution energy consumption in the whole network and increasing scalability. There...
Design and Optimization of Energy Efficient Wireless Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeeid (Supervisor)
Abstract
Wireless Sensor Network (WSN) is a rapidly growing technology that is used to meet different requirements of a wide range of applications. Energy conservation is one of the main design challenges in WSNs due to limited energy resources. Routing plays a significant role for energy efficient communication in WSNs. Although there are many research studies that utilize energy efficient routing to conserve energy in WSNs, there are a few works that took advantage of machine learning techniques for saving energy through energy efficient routing.The main goal of this thesis is to indicate that machine learning is a functional approach to many problems in WSNs. To fulfill this goal we first...
Enhancement of Animal Tracking by Means of Wireless Sensor Network Using Machine Learning Technique
, M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeed (Supervisor) ; Ghorshi, Mohammad Ali (Co-Advisor)
Abstract
A Wireless Sensor Network is one of the attended research context that is used to meet different requirements of a wide range of applications. One of the usages of WSNs is in Animal Tracking. Many Animal Tracking methods have weaknesses that can be enhanced. By considering WSN properties and many different usages of Machine Learning techniques reported in a variety of fields and considering Animal Tracking methods characteristics, WSNs can be improved by applying Machine Learning techniques. The main goal of this thesis is to show that with help of Machine Learning techniques, performance of Animal Tracking by means of Wireless Sensor Networks increases. To fulfill this goal, we first...
Determining the Strength of Barrier Coverage in Wireless Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Ghodsi, Mohammad (Supervisor)
Abstract
Given a set of obstacles as an arrangement of geometric shapes in the plane, we would like to find a path from the initial point s to the target point t that crosses the minimum number of obstacles. In other words, the goal is to determine the minimum number of obstacles that need to be removed to exist a collision-free path between s and t.On one hand, this problem can be used for measuring the strength of barrier coverage which is a fundamental concept in wireless sensor networks (WSNs), and on the other hand, it has been considered as a robot motion-planning problem. The objective of barrier coverage is to guarantee that any path from the start point to the target point, will intersect at...
Using Clustering for Routing in Sensor Network
, M.Sc. Thesis Sharif University of Technology ; Beigy, Hamid (Supervisor)
Abstract
Wireless sensor networks consist of many small sensor nodes which suffer from some limitations like energy level, band width, processing ability and memory; therefore, decreasing energy consumption, increasing network lifetime and scalability are the main challenges in the area of routing in wireless sensor networks. In the field of routing in sensor networks, many algorithms have been suggested, one group of which is clusterbased hierarchical algorithms. The main goals of such algorithms are reducing energy consumption, distributing consumed energy within whole network and increasing scalability of algorithm. There are some problems in most of cluster-based routing algorithms which cause...