Search for: energy-utilization
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    Energy and utility optimization in wireless networks with random access

    , Article 2007 IEEE International Conference on Communications, ICC'07, Glasgow, Scotland, 24 June 2007 through 28 June 2007 ; 2007 , Pages 3799-3804 ; 05361486 (ISSN); 1424403537 (ISBN); 9781424403530 (ISBN) Khodaian, A ; Hossein Khalaj, B ; Sharif University of Technology
    Energy consumption is a main issue of concern in wireless networks. Energy minimization increases the time that networks' nodes work properly without recharging or substituting batteries. Another criterion for network performance is data transmission rate which is usually quantified by a network utility function. There exists an inherent tradeoff between these criteria and enhancing one of them can deteriorate the other one. In this paper, we consider both Network Utility Maximization (NUM) and energy minimization in a bi-criterion optimization problem. The problem is formulated for Random Access (RA) Medium Access Control (MAC) for ad-hoc networks. First, we optimize performance of the MAC... 

    Energy-optimized on-chip networks using reconfigurable shortcut paths

    , Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 24 February 2011 through 25 February 2011 ; Volume 6566 LNCS , February , 2011 , Pages 231-242 ; 03029743 (ISSN) ; 9783642191367 (ISBN) Teimouri, N ; Modarressi, M ; Tavakkol, A ; Sarbazi Azad, H ; Sharif University of Technology
    Topology is an important network attribute that greatly affects the power, performance, cost, and design time/effort of NoCs. In this paper, we propose a novel NoC architecture that can exploit the benefits of both application-specific and regular NoC topologies. To this end, a subset of NoC links bypass the router pipeline stages and directly connect remotely located nodes. This results in an NoC which holds both fixed connections between adjacent nodes and long connections virtually connecting non-adjacent nodes. These shortcut paths are constructed at run-time by employing a simple and fast mechanism composed of two processes: on-chip traffic monitoring and path reconfiguration. The... 

    Fitness function improvement of evolutionary algorithms used in sensor network optimisations

    , Article IET Networks ; Volume 7, Issue 3 , 2018 , Pages 91-94 ; 20474954 (ISSN) Hoseinpour, A ; Jafari Lahijani, M ; Hoseinpour, M ; Kazemitabar, J ; Sharif University of Technology
    Institution of Engineering and Technology  2018
    Recent advances in wireless sensor network (WSN) technology are enabling the deployment of large-scale and collaborative sensor networks. WSNs face several challenges such as security, localisation, and energy consumption. To resolve these issues, evolutionary algorithms can be helpful. The core of every evolutionary algorithm is its fitness function. The drawbacks of fitness functions used in the literature will be investigated and some solutions will be suggested. The simulation results clearly show the improvement due to suggested solutions. © The Institution of Engineering and Technology 2017  

    Effects of human pilot energy expenditure on pilot evaluation of handling qualities

    , Article Collection of Technical Papers - AIAA Atmospheric Flight Mechanics Conference, Providence, RI, 16 August 2004 through 19 August 2004 ; Volume 2 , 2004 , Pages 1381-1389 ; 1563477009 (ISBN) Malaek, S. M ; Sajjadi Kia, S ; Sharif University of Technology
    A new methodology has been proposed to model and predict the pilot rating of a typical aircraft for flights through turbulences. The main idea here is to correlate the so-called "pilot rating" to the pilot physical energy demanded by the aircraft in a given flight condition and flying task. The proposed methodology, in addition to the other known factors, accepts the level of the human pilot physical energy consumed in each suitable period of time as well as the rate of energy consumption in the same period. These two, form the prime factors to predict the pilot rating in flying tasks that have a reasonable duration. Different case studies conducted by the authors show that for cases like... 

    Synthesis of a compensated kick pattern for humanoid robots using conservation laws

    , Article 2006 ASME International Design Engineering Technical Conferences and Computers and Information In Engineering Conference, DETC2006, Philadelphia, PA, 10 September 2006 through 13 September 2006 ; Volume 2006 , 2006 ; 079183784X (ISBN); 9780791837849 (ISBN) Meghdari, A ; Tamaddoni, S. H ; Jafari, F ; Sharif University of Technology
    American Society of Mechanical Engineers  2006
    The motivation of this work is to synthesize a kicking pattern for a humanoid robot with consideration of various objectives such as retaining its balance even after the kick is done and reducing the undesired angular momentum using both hands and torso. This kick pattern is designed so that a desirable ball velocity is achieved. In this paper, the law of conservation of angular momentum is used to generate a less energy consuming trajectory. Effectiveness of the proposed method is verified using computer simulation and is tested on Sharif CEDRA humanoid robot. Copyright © 2006 by ASME  

    Investigation of development features of membrane cell chlor-alkali technology

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Haddadi, A. M ; Babazadeh, F ; Kazemeini, M ; Sharif University of Technology
    As the membrane technology developed at the last 30 years, the relevant processes have been significantly developed. One of which is the chlor alkali technology. The development of membrane technology and its effect on Chlor-Alkali process is capable of evaluation in to two different fields, environmental and energy consumption. Some of environmental problems of mercury and diaphragm processes because of their technological development have been eliminated the energy consumption of these processes is significantly decreased especially in membrane and diaphragm processes. Recently investigation in the field of membrane cell is more focused on cell construction, depolarized cathodes, and fluid... 

    A novel joint routing and power management algorithm for energy-constraint Ad-hoc Sensor Network

    , Article 24th IEEE International Performance, Computing, and Communications Conference, IPCCC 2005, Phoenix, AZ, 7 April 2005 through 9 April 2005 ; 2005 , Pages 395-400 Farrokhfal, Y. G ; Shah Mansouri, V ; Pakravan, M. R ; Dahlberg T ; Oliver R ; Sen A ; Xue G ; Sharif University of Technology
    In this paper a combination of routing and power management within the context of wireless Ad-hoc Sensor Networks is considered. Using lower layer information (e.g. collision that is considered in MAC layer) is another novel concern which is used in routing decisions. More specifically in this paper we introduce a cross-layer design in which each node dynamically chooses the number of its neighbors and adjusts its power just enough to reach its farthest determined neighbor. In this algorithm the power of transmission and collision are used as metrics for routing and the number of neighbors in which the total energy consumption in data transmission will be the minimum is selected. © 2005 IEEE... 

    Cross-layer flooding for sensor networks without location information

    , Article 2nd IEEE International Conference on Mobile Ad-hoc and Sensor Systems, MASS 2005, Washington, 7 November 2005 through 10 November 2005 ; Volume 2005 , 2005 , Pages 110-114 ; 0780394666 (ISBN); 9780780394667 (ISBN) Ghiassi Farrokhfal, Y ; Pakravan, M. R ; Sharif University of Technology
    Flooding algorithm is one of the most significant algorithms used in sensor networks. Although simple, this algorithm causes a large amount of energy and bandwidth to be wasted. The most important application of flooding is RREQ flooding in initial step of most routing algorithms. Although simple, this algorithm causes a large amount of energy and bandwidth to be wasted. Most previous efficient flooding algorithms use location information which is impossible for simple node in sensor network. Some others are not suitable for RREQ flooding due to eliminating redundant retransmissions. We present a modified flooding that simultaneously decreases energy consumption as well as network delay.... 

    Investigating the impacts of plug-in hybrid electric vehicles on power distribution systems

    , Article IEEE Transactions on Smart Grid ; Vol. 4, issue. 3 , 2013 , p. 1351-1360 ; ISSN: 19493053 Shafiee, S ; Fotuhi-Firuzabad, M ; Rastegar, M ; Sharif University of Technology
    Despite the economic and environmental advantages of plug-in hybrid electric vehicles (PHEVs), the increased utilization of PHEVs brings up new concerns for power distribution system decision makers. Impacts of PHEVs on distribution networks, although have been proven to be noticeable, have not been thoroughly investigated for future years. In this paper, a comprehensive model is proposed to study the PHEV impacts on residential distribution systems. In so doing, PHEV fundamental characteristics, i.e., PHEV battery capacity, PHEV state of charge (SOC), and PHEV energy consumption in daily trips, are accurately modeled. As some of these effective characteristics depend on vehicle owner's... 

    Application specific router architectures for NoCs: An efficiency and power consumption analysis

    , Article Mechatronics ; Vol. 22, issue. 5 , August , 2012 , pp. 531-537 ; ISSN: 9574158 Najjari, N ; Sarbazi-Azad, H ; Sharif University of Technology
    Networks on chip (NoC) have been proposed as a solution to mitigate complex on-chip communication problems. NoCs are composed of intellectual properties (IP) which are interconnected by on-chip switching fabrics. A step in the design process of NoCs is hardware virtualization which is mapping the IP cores onto the tiles of a chip. The communication among the IP cores greatly affects the performance and power consumption of NoCs which itself is deeply related to the placement of IPs onto the tiles of the network. Different mapping algorithms have been proposed for NoCs which allocate a set of IPs to given network topologies. In these mapping algorithms, there is a restriction which limits IPs... 

    Designing gear-shift pattern for an electric vehicle to optimize energy consumption

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Vol. 11 , 2010 , pp. 837-846 ; ISBN: 9780791844489 Rahimi, M. A ; Salehi, R ; Alasty, A ; Sharif University of Technology
    In this paper optimization of energy consumption in an electric vehicle is presented. The main idea of this optimization is based on selecting the best gear level in driving the vehicle. Two algorithms for optimization are introduced which are based on fuzzy rules and fuzzy controllers. In first algorithm, fuzzy controller simulates energy consumption in different gear levels, and chooses the optimum gear level. While in second method, fuzzy controller detects the optimum gear level by measuring the vehicle's average speed and acceleration. To investigate the performance of these controllers, a model of TOSAN vehicle is developed and the controllers outputs are checked in simulation of TOSAN... 

    WCCP: A congestion control protocol for wireless multimedia communication in sensor networks

    , Article Ad Hoc Networks ; Volume 13, Issue , February , 2014 , Pages 516-534 ; ISSN: 15708705 Mahdizadeh Aghdam, S ; Khansari, M ; Rabiee, H. R ; Salehi, M ; Sharif University of Technology
    The growing interest in applications of Wireless Multimedia Sensor Networks (WMSNs) imposes new challenges on congestion control protocols in such networks. In this paper, we propose a new content-aware cross layer WMSN Congestion Control Protocol (WCCP) by considering the characteristics of multimedia content. WCCP employs a Source Congestion Avoidance Protocol (SCAP) in the source nodes, and a Receiver Congestion Control Protocol (RCCP) in the intermediate nodes. SCAP uses Group of Picture (GOP) size prediction to detect congestion in the network, and avoids congestion by adjusting the sending rate of source nodes and distribution of the departing packets from the source nodes. In... 

    Modelling useful energy demand system as derived from basic needs in the household sector

    , Article Energy Efficiency ; Volume 7, Issue 5 , 2014 , Pages 903-921 ; ISSN: 1570646X Barkhordar, Z. A ; Saboohi, Y ; Sharif University of Technology
    Inter-fuel substitution in the household sector depends on whether their target energy use is similar or not. To account for the effect of end-use application on energy demand, the concept of useful energy is utilized in which energy carriers are grouped according to their end-use applications. Useful energy is assumed as a commodity demanded to satisfy needs. Therefore, it should possess certain characteristics in accordance with the nature of basic needs. These characteristics were investigated through a two-level budgeting system with demographic variables indicating rural and urban households of Iran. The model has been applied to estimate the behavioural parameters such as income and... 

    Numerical analysis of ciliary beat in Paramecium: Increasing ciliary spacing as a low energy cost method for maneuvering

    , Article Recent Patents on Mechanical Engineering ; Volume 6, Issue 3 , September , 2013 , Pages 227-237 ; 1874477X (ISSN) Nematollahi, A ; Zand, M. M ; Sharif University of Technology
    In recent years, a number of patents have been devoted to designing micro robots for minimally invasive therapies inspired by Paramecium. Paramecium changes its swimming direction due to application of an external magnetic or electric field. Changing ciliary beat direction and frequency have been identified as possible methods for maneuvering through water; however, effects of variations in ciliary spacing on swimming trajectory have been poorly studied. In this work, it is aimed to analyze the effects of adjusting the ciliary spacing on swimming trajectory. For determining the swimming trajectory, Paramecium membrane is discretized to boundary elements with length of 15μm on which there are... 

    A novel and low-energy PKC-based key agreement protocol for WSNs

    , Article 2013 10th International ISC Conference on Information Security and Cryptology, ISCISC 2013 ; 2013 Ghasemzadeh, H ; Aref, M. R ; Payandeh, A ; Sharif University of Technology
    IEEE Computer Society  2013
    Security is a critical and vital task in WSNs. Recently, key management as the core of a secure communication has received lots of attention, but in most of the proposed methods security has been compromised in favor of reducing energy consumption. Consequently, perfect resiliency has not been achieved by most of the previous works. Hostile environment, ability of adversary to capture the nodes, and dead nodes with sensitive data scattered in the region, calls for a more secure and yet practical method. This paper proposes a novel authentication scheme based on broadcast messages from BS to improve security of key management system. Through simulation it is shown that energy consumption of... 

    Energy aware data compression in WSN

    , Article Lecture Notes in Electrical Engineering ; Volume 152 , 2013 , Pages 673-682 ; 18761100 (ISSN) ; 9781461435341 (ISBN) Izadian, R ; Manzuri, M. T ; Sharif University of Technology
    Wireless sensor networks (WSNs) use energy for their sensing, computation, and communication. To increase the lifetime of the network, sensor nodes are equipped with energy storage devices. Recharging of their batteries is not possible in most applications. Therefore, energy consumption needs to be monitored and limited to increase the energy consumption performance of the network. The communication module uses the highest amount of energy in a WSN. Among several methods offered to reduce the energy consumption, data compression has the highest effect on the energy usage by reducing the number of bits to be broadcasted. This paper illustrates an energy consumption reduction in WSN by... 

    S-NC: Structure-free network coding-aware routing in wireless sensor networks

    , Article MSWiM'12 - Proceedings of the 15th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems ; 2012 , Pages 403-407 ; 9781450316286 (ISBN) Enayati Noabadi, E ; Yousefi, H ; Movaghar, A ; Sharif University of Technology
    Network Coding (NC) is an emerging technique that helps wireless networks to have higher throughput and better energy efficiency. In this paper, a novel network coding-aware routing (S-NC) which uses NC to improve reliability and robustness in unreliable WSNs is proposed. It is based on a structure-free routing algorithm as the underlying routing engine which employs neighbor queue length to increase coding opportunity; while exploiting a spatial coding method to control the amount of redundancy. To the best of our knowledge, this is the first study on the topic of network codingaware routing in Wsns. Simulation results in Tossim demonstrate that S-NC significantly improves the performance... 

    Efficient energy-aware routing with redundancy elimination

    , Article IEEE Journal on Selected Areas in Communications ; Volume 33, Issue 12 , 2015 , Pages 2815-2825 ; 07338716 (ISSN) Omidvar, N ; Tsang, D. H. K ; Pakravan, M. R ; Lau, V. K. N ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Energy-Aware routing is a promising technique for reducing energy consumption in future networks. Under this scheme, traffic loads are aggregated over a subset of the network links, allowing other links to be turned off to save energy. Since the capacity of links is the main limiting constraint in this problem, to further improve energy saving, the idea of using redundancy elimination (RE) in energy-Aware routing has been proposed. As performing RE in routers consumes some energy, it should be specified, which routers should perform RE and which links should be deactivated so that the total energy consumption of the network is minimized. As a result, the problem of energy-Aware routing with... 

    Dynamically adaptive register file architecture for energy reduction in embedded processors

    , Article Microprocessors and Microsystems ; Volume 39, Issue 2 , March , 2015 , Pages 49-63 ; 01419331 (ISSN) Khavari Tavana, M ; Ahmadian Khameneh, S ; Goudarzi, M ; Sharif University of Technology
    Elsevier  2015
    Energy reduction in embedded processors is a must since most embedded systems run on batteries and processor energy reduction helps increase usage time before needing a recharge. Register files are among the most power consuming parts of a processor core. Register file power consumption mainly depends on its size (height as well as width), especially in newer technologies where leakage power is increasing. We provide a register file architecture that, depending on the application behavior, dynamically (i) adapts the width of individual registers, and (ii) puts partitions of temporarily unused registers into low-power mode, so as to save both static and dynamic power. We show that our scheme... 

    A distributed truthful routing protocol for mobile ad hoc networks

    , Article Proceedings of ICCIA 2010 - 2010 International Conference on Computer and Information Application, 2 November 2010 through 4 November 2010, Tianjin ; 2010 , Pages 133-140 ; 9781424485963 (ISBN) Shirzad, F ; Movaghar, A ; Shirzadeh, E ; Sharif University of Technology
    In Mobile Ad hoc Networks (MANETs), nodes depend on each other for routing and forwarding their packets. However, to save power and other resources, nodes belonging to independent authorities may behave selfishly, and not cooperate in network activities. Such selfish behaviour poses a real threat to the proper functioning of MANETs. To cope with this situation, a motivation stimulation mechanism is required to provide sufficient incentives for nodes to forward other nodes' packets. One appropriate approach is to have network nodes pay in order to motivate them to cooperate with the protocol. To achieve truthfulness, the payment should be based on the cost of transmission of packets. Since...