Hossein Ashrafzadeh | AmirKabir University Of Technology (original) (raw)
Papers by Hossein Ashrafzadeh
Today Localization in wireless sensor networks is the topic of many researches. Methods of locali... more Today Localization in wireless sensor networks is the topic of many researches. Methods of localization in the sensor networks are divided into two sets of anchor-based and anchor-free. Furthermore, localization methods may work centralized or distributed. Distributed and anchor-free are methods, which use clustering techniques. In these methods, Localization happens in three principle stages of dividing network into smaller clusters, localization in each cluster and gaining local maps and their combination (map stitching). Lots of clustering methods have been proposed. Moreover, there are Algorithms for gaining the local maps such as MDS. For stitching the local maps, we can assume various strategies such as incremental and concurrent. In this paper, the sensor networks and localization methods based on clustering are introduced, as an example the Leach algorithm with its characteristics and parameters is demonstrated. In addition, a scenario in which the LEACH algorithm is used for clustering is proposed and an evaluation of its analytical results is done with the NS2 simulation tool.
2ND INTERNATIONAL CONGRESS OF ELECTRICAL ENGINEERING, COMPUTER SCIENCE AND INFORMATION TECHNOLOGY (IT2015), 2015
INTERNATIONAL CONFERENCE ON COMPUTER ENGINEERING AND IT (CIT 2016), 2016
The emerging Internet of Things is believed to be the next generation of the internet, in which c... more The emerging Internet of Things is believed to be the next generation of the internet, in which communications are more than the communication of human-to-human and machine-to-machine. In the Internet of things, billions of things can communicate with each other and with the environment, and exchange information. Recently, research topics and new applications in the field of the Internet of things have been formed. In this article, we discuss the concept of the Internet of things, the barriers and challenges facing the development of the Internet of things, and its applications in the world around. Also, with the growing of IoT the set of IoT-Communication technologies is also continuously expanding. A general overview of the main communication technologies in the field of the Internet of Things which can have a beneficial impact in the realization of Smart World, will be mentioned and compared in different aspects. Keywords—IoT, Applications, Communication technologies, Cellular Ne...
Wireless Mesh Networks are one of the important components in the future convergent networks, whi... more Wireless Mesh Networks are one of the important components in the future convergent networks, which can support a flexible bandwidth in large geographical areas. Since using a radio interface on each node provides the possibility of optimum use of available bandwidth capacity, the tendency toward the use of multiple radio interfaces on each node, which allocates a separate radio channel to each interface, is increased [1]. As in the standard protocols the number of available channels is limited, the main issue, here is how to use the available channels. Therefore, in this paper the performance of channel allocation algorithms in the multiradio multi-channel in wireless mesh networks is investigated with the approach of maximizing efficiency of network and minimizing the interference. Studied methods for channel allocation in this paper applied both types of orthogonal and overlap channels.
In today's world everything is changing rapidly and development of technology and information has... more In today's world everything is changing rapidly and development of technology and information has changed many existing facilities in the cultural, social, political and economic fields. Therefore, education like other changes in society and expectations that a society has from its people must change in an appropriate and acceptable way. Distance learning system (electronic) is a new approach and solution for institutions that want to move toward technology in order to change teaching methods and their environments. This system makes it possible to achieve modern education methods in an exhaustive and best way. (1( In the virtual education, all systems, activities and policies must be designed in support of the feature of interaction between students and educational materials and courses. (2lThe authors of this paper try to understand the concepts, characteristics and definition of a virtual university to find the strengths and weaknesses of virtual universities and realize the solutions for the weak points. (31
Awards and Honors by Hossein Ashrafzadeh
Today Localization in wireless sensor networks is the topic of many researches. Methods of locali... more Today Localization in wireless sensor networks is the topic of many researches. Methods of localization in the sensor networks are divided into two sets of anchor-based and anchor-free. Furthermore, localization methods may work centralized or distributed. Distributed and anchor-free are methods, which use clustering techniques. In these methods, Localization happens in three principle stages of dividing network into smaller clusters, localization in each cluster and gaining local maps and their combination (map stitching). Lots of clustering methods have been proposed. Moreover, there are Algorithms for gaining the local maps such as MDS. For stitching the local maps, we can assume various strategies such as incremental and concurrent. In this paper, the sensor networks and localization methods based on clustering are introduced, as an example the Leach algorithm with its characteristics and parameters is demonstrated. In addition, a scenario in which the LEACH algorithm is used for clustering is proposed and an evaluation of its analytical results is done with the NS2 simulation tool.
2ND INTERNATIONAL CONGRESS OF ELECTRICAL ENGINEERING, COMPUTER SCIENCE AND INFORMATION TECHNOLOGY (IT2015), 2015
INTERNATIONAL CONFERENCE ON COMPUTER ENGINEERING AND IT (CIT 2016), 2016
The emerging Internet of Things is believed to be the next generation of the internet, in which c... more The emerging Internet of Things is believed to be the next generation of the internet, in which communications are more than the communication of human-to-human and machine-to-machine. In the Internet of things, billions of things can communicate with each other and with the environment, and exchange information. Recently, research topics and new applications in the field of the Internet of things have been formed. In this article, we discuss the concept of the Internet of things, the barriers and challenges facing the development of the Internet of things, and its applications in the world around. Also, with the growing of IoT the set of IoT-Communication technologies is also continuously expanding. A general overview of the main communication technologies in the field of the Internet of Things which can have a beneficial impact in the realization of Smart World, will be mentioned and compared in different aspects. Keywords—IoT, Applications, Communication technologies, Cellular Ne...
Wireless Mesh Networks are one of the important components in the future convergent networks, whi... more Wireless Mesh Networks are one of the important components in the future convergent networks, which can support a flexible bandwidth in large geographical areas. Since using a radio interface on each node provides the possibility of optimum use of available bandwidth capacity, the tendency toward the use of multiple radio interfaces on each node, which allocates a separate radio channel to each interface, is increased [1]. As in the standard protocols the number of available channels is limited, the main issue, here is how to use the available channels. Therefore, in this paper the performance of channel allocation algorithms in the multiradio multi-channel in wireless mesh networks is investigated with the approach of maximizing efficiency of network and minimizing the interference. Studied methods for channel allocation in this paper applied both types of orthogonal and overlap channels.
In today's world everything is changing rapidly and development of technology and information has... more In today's world everything is changing rapidly and development of technology and information has changed many existing facilities in the cultural, social, political and economic fields. Therefore, education like other changes in society and expectations that a society has from its people must change in an appropriate and acceptable way. Distance learning system (electronic) is a new approach and solution for institutions that want to move toward technology in order to change teaching methods and their environments. This system makes it possible to achieve modern education methods in an exhaustive and best way. (1( In the virtual education, all systems, activities and policies must be designed in support of the feature of interaction between students and educational materials and courses. (2lThe authors of this paper try to understand the concepts, characteristics and definition of a virtual university to find the strengths and weaknesses of virtual universities and realize the solutions for the weak points. (31