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Search Results: 1 - 10 of 12882 matches for " Mohammad Hossien YAGHMAEE "
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AEESPAN: Automata Based Energy Efficient Spanning Tree for Data Aggregation in Wireless Sensor Networks  [PDF]
Zahra ESKANDARI, Mohammad Hossien YAGHMAEE
Wireless Sensor Network (WSN) , 2009, DOI: 10.4236/wsn.2009.14039
Abstract: In Wireless Sensor Networks (WSNs), sensor nodes are developed densely. They have limit processing ca-pability and low power resources. Thus, energy is one of most important constraints in these networks. In some applications of sensor networks, sensor nodes sense data from the environment periodically and trans-mit these data to sink node. In order to decrease energy consumption and so, increase network’s lifetime, volume of transmitted data should be decreased. A solution, which is suggested, is aggregation. In aggrega-tion mechanisms, the nodes aggregate received data and send aggregated result instead of raw data to sink, so, the volume of the transmitted data is decreased. Aggregation algorithms should construct aggregation tree and transmit data to sink based on this tree. In this paper, we propose an automaton based algorithm to con-struct aggregation tree by using energy and distance parameters. Automaton is a decision-making machine that is able-to-learn. Since network’s topology is dynamic, algorithm should construct aggregation tree peri-odically. In order to aware nodes of topology and so, select optimal path, routing packets must be flooded in entire network that led to high energy consumption. By using automaton machine which is in interaction with environment, we solve this problem based on automat learning. By using this strategy, aggregation tree is reconstructed locally, that result in decreasing energy consumption. Simulation results show that the pro-posed algorithm has better performance in terms of energy efficiency which increase the network lifetime and support better coverage.
Tree Based Energy and Congestion Aware Routing Protocol for Wireless Sensor Networks  [PDF]
Amir Hossein Mohajerzadeh, Mohammad Hossien Yaghmaee
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.22021
Abstract: Wireless Sensor Networks (WSNs) have inherent and unique characteristics rather than traditional networks. They have many different constraints, such as computational power, storage capacity, energy supply and etc; of course the most important issue is their energy constraint. Energy aware routing protocol is very important in WSN, but routing protocol which only considers energy has not efficient performance. Therefore considering other parameters beside energy efficiency is crucial for protocols efficiency. Depending on sensor network application, different parameters can be considered for its protocols. Congestion management can affect routing protocol performance. Congestion occurrence in network nodes leads to increasing packet loss and energy consumption. Another parameter which affects routing protocol efficiency is providing fairness in nodes energy consumption. When fairness is not considered in routing process, network will be partitioned very soon and then the network performance will be decreased. In this paper a Tree based Energy and Congestion Aware Routing Protocol (TECARP) is proposed. The proposed protocol is an energy efficient routing protocol which tries to manage congestion and to provide fairness in network. Simulation results shown in this paper imply that the TECARP has achieved its goals.
The Overload Reduction in SIP Servers through Exact Regulation of the Retransmission Timer of the Invite Message  [PDF]
Ahmadreza Montazerolghaem, Mohammad Hossein Yaghmaee
Journal of Computer and Communications (JCC) , 2013, DOI: 10.4236/jcc.2013.12002

To initiate voice, image, instant messaging and general multimedia communication, the Session communication must initiate between two participants. SIP (Session initiation protocol) is an application layer control, which task is creating management, and terminating this kind of Sessions. With regard to the independence of SIP from the Transport layer protocols, the SIP messages can be transferred on a variety of Transport layer protocols such as TCP or UDP. The mechanism of Retransmission, which has been embedded in SIP, is able to compensate the missing Packet loss, if needed. The application of this mechanism is when SIP messages are transmitted on an unreliable transmission layer protocol such as UDP. This mechanism, while facing with SIP proxy with overload, causes excessive filling of proxy queue, delays the increase of other contacts and adds the amount of the proxy overload. We in this article, while using UDP, as the Transport layer protocol, by regulating the Invite Retransmission Timer appropriately (T1), have improved the SIP functionality. Therefore, by proposing an Adaptive Timer of Invite message retransmission, we have tried to improve the time of Session initiation and as a result, improving the performance. The performance of the proposed SIP, by the SIPP software in a real network environment has been implemented and evaluated and its accuracy and performance has been demonstrated.

A QoS-Based Multichannel MAC Protocol for Two-Tiered Wireless Multimedia Sensor Networks  [PDF]
GholamHossein EkbataniFard, Mohammad H. Yaghmaee, Reza Monsefi
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.37084
Abstract: Rapid penetration of small customized wireless devices and enormous growth of wireless communication technologies has already set the stage for large-scale deployment of wireless sensor networks. Offering precise quality of service (QoS) for multimedia transmission over sensor networks has not received significant attention. However offering some better QoS for wireless multimedia over sensor networks raises significant challenges. In this paper, we propose an adaptive Cross-Layer multi-channel QoS-MAC protocol to support energy-efficient, high throughput, and reliable data transmission in Wireless Multimedia Sensor Network (WMSNs). Our proposed protocol use benefit of TDMA and CSMA/CA to adaptively assign channels and timeslots to active multimedia sensor nodes in clusters. Simulations show that the proposed system achieves the performance objectives of WMSNs with increased network throughput at the cost of a small control and energy overhead.
COCM: Class Based Optimized Congestion Management Protocol for Healthcare Wireless Sensor Networks  [PDF]
Abbas Ali Rezaee, Mohammad Hossein Yaghmaee, Amir Masoud Rahmani
Wireless Sensor Network (WSN) , 2013, DOI: 10.4236/wsn.2013.57017

Wireless Sensor Networks (WSNs) consist of numerous sensor nodes which can be used in many new emerging applications like healthcare. One of the major challenges in healthcare environments is to manage congestion, because in applications, such as medical emergencies or patients remote monitoring, transmitted data is important and critical. So it is essential in the first place to avoid congestion as much as possible and in cases when congestion avoidance is not possible, to control the congestion. In this paper, a class based congestion management protocol has been proposed for healthcare applications. We distinguish between sensitive, non-sensitive and control traffics, and service the input traffics based on their priority and quality of service requirements (QoS). The proposed protocol which is called COCM avoids congestion in the first step using multipath routing. The proposed AQM algorithm uses separate virtual queue's condition on a single physical queue to accept or drop the incoming packets. In cases where input traffic rate increases and congestion cannot be avoided, it mitigates congestion by using an optimized congestion control algorithm. This paper deals with parameters like end to end delay, packet loss, energy consumption, lifetime and fairness which are important in healthcare applications. The performance of COCM was evaluated using the OPNET simulator. Simulation results indicated that COCM achieves its goals.

A Constraint Based Routing Algorithm for Multimedia Networking
Maryam Baradaran,Mohammad Hossein Yaghmaee
IAENG International Journal of Computer Science , 2007,
Fuzzy Jobs: A Fuzzy Extension to The Jobs Algorithm
Mohammad Hossein Yaghmaee,Ghazale Khojasteh Tousi
IAENG International Journal of Computer Science , 2007,
A Proportional Jitter Scheduling and Buffer Management Algorithm for Differentiated Services Networks
Mohammad Hossein Yaghmaee,Ghazale Khojasteh Tousi
Journal of Networks , 2008, DOI: 10.4304/jnw.3.8.35-44
Abstract: This paper proposes a method for scheduling and buffer management in differentiated services networks which is based on JoBS algorithm. JoBS differentiates traffic classes base on delay and loss rate. Furthermore, it supports both relative and absolute constraints. Nowadays with the expansion of Internet traffic and its diversified service requests, the focus is on requirement of new traffic used on the Internet. The proposed method focuses on packet scheduling based on the jitter (variance of delay), since new traffics that will be mostly used in the next generation Internet are more susceptible to variance of delay. Drawing on concepts of jitter and the difference between scheduling base on jitter and delay, this paper analyzes the effectiveness of the proposed method by simulation examples that are presented here. Results show that proposed method can proportionally differentiated classes based on delay, loss rate and jitter. Also, it fulfills the absolute conditions which are defined by absolute parameters. This paper concludes with the suggestion that this method comparing to the JoBS can proportionally differentiate classes based on more parameters and its result of differentiation is better.
Sip Overload Control Testbed: Design, Building and Evaluation
Ahmad Reza Montazerolghaem,Mohammad Hossein Yaghmaee
Computer Science , 2013,
Abstract: Having facilities such as being in text form, end-to-end connection establishment, and being independence from the type of transmitted data, SIP protocol is a good choice for signaling protocol in order to set up a connection between two users of an IP network. Although utilization of SIP protocol in a wide range of applications has made various vulnerabilities in this protocol, amongst which overload could make serious problems in SIP servers. A SIP is overloaded when it does not have sufficient resources (majorly CPU processing power and memory) to process all messages. In this paper the window-based overload control mechanism which does not require explicit feedback is developed and implemented on Asterisk open source proxy and evaluated. The results of implementation show that this method could practically maintain throughput in case of overload. As we know this is the only overload control method which is implemented on a real platform without using explicit feedback. The results show that the under load server maintains its throughput at the maximum capacity.
Assessment Role of Participation in Narcotic Anonymous in Opiate Dependents during Abstinence
Hossien Zare,Ahmad Alipoor,Parvin Aghamohammadhasani,Mohammad Nazer
Zahedan Journal of Research in Medical Sciences , 2012,
Abstract: Background: The activity level of Narcotics Anonymous group (NA) is expanding in many countries, including Iran. Some research has confessed the benefits of 12-step NA approach compared with similar methods. In the present study, the role of regular participation of opioid addicts in the NA group was studied in terms of abstinence rate and compared with routine program of detoxification centers of the person Welfare Organization and Medical Sciences University. Materials and Methods: All addicts who attempted to quit in self-introducer clinical centers of Medical Sciences University and the Welfare Organization of Rafsanjan were suggested to participate and not to participate in NA, based on even and odd numbers, respectively. Among them, two equal 120-person (NA and control) groups were selected, then evaluated every three months and followed up for 12 months. Their status was assessed through questionnaires, interviews, and morphine tests.Results: The purity rate of NA group with 8.49 months was significantly different with normal addicts in 5.19 months (p=0.001). The recurrence rate at 12 months was significantly lower in the NA group compared with the control group, calculated through independent t-test (p=0.001). Quitting history and addiction duration in the NA group was significantly higher than control group.Conclusion: The findings of the research support a better prognosis for participants of NA group. Further researches are recommended to provide useful clinical information for patients and professionals.
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