Search for: power-consumption
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    Improving the energy/power consumption of parallel decimal multipliers

    , Article Indian Journal of Science and Technology ; Vol. 7, issue. 3 , 2014 , p. 276-281 Malekpour, A ; Ejlali, A ; Sharif University of Technology
    Decimal arithmetic has gained intensive attention in the last decade. Most commercial, financial, scientific, and internet-based applications need their data to be precise, while binary number system loses preciseness in some cases. The latency and area are two major factors in existing research works on decimal multiplication. However, energy/power consumption is another important factor in today's digital systems. Hence, in this paper we proposed a new low power decimal adder based on prediction technique for decreasing the energy/power consumption of parallel decimal multiplication and show its impacts on one of the well-known parallel decimal multipliers architecture. Our observations... 

    Dynamic Analysis of Electrical Energy Consumption By Means of System Dynamics Method With considering of Removing Energy Subsidy

    , M.Sc. Thesis Sharif University of Technology Givehei, Mohammad Reza (Author) ; Ehsan, Mehdi (Supervisor)
    The analysis of electrical energy consumption parameters such as rate and amount of consumption, plays an important role in the planning of power systems. Because the dynamic analysis and evaluation of these parameters provides a detailed forecast of consumption and power system load. these forecasts is given to planners and engineers as the input of power system planning .Given that the electrical energy consumption system can be thought as a dynamic system, System Dynamics (SD) method would be very appropriate for modeling and analyzing its behavior. In this thesis, based on the SD and by means of dynamic loops, a comprehensive dynamic system for electrical energy is introduced. So the... 

    Modeling and Evaluation of Performability in Cloud Computing Considering Power Consumption

    , Ph.D. Dissertation Sharif University of Technology Ataie Dadavi, Ehsan (Author) ; Movaghar, Ali (Supervisor)
    Considering current problems in performance evaluation of the Cloud and its management policies and strategies, this thesis presents different approaches for simultaneous evaluation of the performance, dependability, and power consumption of Infrastructure-as-a-Service (IaaS) clouds. The proposed approaches use Stochastic Reward Nets (SRNs) and Stochastic Activity Networks (SANs) to model and evaluate performability and power consumption of cloud systems. In all of the proposed approaches, the cloud resource management system is power-aware. It means that idle Physical Machines (PMs), network equipment, and supporting subsystems are kept in powered-off or standby modes, as much as possible,... 

    Reducing Power Consumption in NoCs Through Adaptive Data Encoding

    , M.Sc. Thesis Sharif University of Technology Taassori, Meysam (Author) ; Hessabi, Shahin (Supervisor)
    Recent advances in VLSI technology have led to integrate a few billion transistors on a chip. Systems on Chip provide solutions to the design problems of these systems. As technology scales down to deep sub-micron dimensions, the delay and power consumption of global interconnects become the major bottleneck in SoC design. Networks on Chip (NoCs) have been proposed as an efficient, scalable, modular and reliable solution to provide on chip communication in large VLSI design. The market trend to mobile digital systems and battery-powered devices add power as a new dimension to VLSI design space in addition to speed and area. Interconnect wires dissipate a significant fraction of power... 

    Investigation of Demand Response to Changing the Household Electricity Meter from Single Stroke Case to Three Stroke Case; Evidence from Tehran Interior Region 2

    , M.Sc. Thesis Sharif University of Technology Sadeghi, Saeed (Author) ; Vesal, Mohammad (Supervisor)
    This study investigates consumers’ response to changing the household electricity meter from single stroke case to three stroke case. Existence of different prices in different hours during the day is the advantage of three stroke electricity meters compared to single stroke ones. Electricity bill data of 19,742 subscribers, in Tehran Interior Region 2, during the period 1387 to 1393, has been used to evaluate this policy. Subscribers who always use only single stroke electricity meters or three stroke ones are considered as the control group; and subscribers who have experienced electricity meter change during the period are considered as the experimental group. Changing electricity meters... 

    Peak Power Management in Fault-tolerant Embedded Systems

    , M.Sc. Thesis Sharif University of Technology Ansari, Mohsen (Author) ; Ejlali, Alireza (Supervisor)
    Technology scaling allows integrating multiple cores onto a single chip to make the mainstream for advanced embedded systems. However, technology scaling is envisaged to aggravate the reliability of on-chip systems due to increasing transient fault rate due to lower voltages and shrinking transistor dimensions that lead to smaller critical charges. Transient faults are typically resulted due to high-energy particle strikes in hardware and manifest as bit flips. Multi-core systems provide a great opportunity to implement reliability mechanisms such as redundant multithreading (RMT) and process level redundancy. Task replication (e.g. RMT) is a well-established technique to achieve high... 

    Power Management Reliability-aware in Mixed-criticality Embedded Systems

    , M.Sc. Thesis Sharif University of Technology Navardi, Mozhgan (Author) ; Ejlali, Alireza (Supervisor)
    Mixed-Criticality Systems (MCSs) include tasks that have multiple levels of criticality and they operate in dierent modes. These systems bring benets such as energy and resource cost saving. However, there are challenges in how to manage available resources in order to achieve high utilization, low power consumption, and required reliability. In many cases, these goals are in conict with each other. For example, if ermal Design Power (TDP) was a constraint on the power consumption of the chip, an approach that increases the utilization, unaware of power consumption, can oversteps TDP and leads to permanent or transient faults. Hence aging balancing and task re-execution are utilized to... 

    Experimental and Numerical Study of the Use of Phase Change Materials on the Performance of Compression Refrigeration Systems

    , M.Sc. Thesis Sharif University of Technology Riahi, Alireza (Author) ; Shafii, Mohammad Behshad (Supervisor)
    In this study, a vapor-compression cooling system utilizing different PCMs has been studied whereby the electricity consumption peak load is shifted. More specifically, the dynamic performance of cooling systems with and without using PCM is evaluated for the hottest day of the year. The proposed system uses the cooling energy to freeze, or “discharge” the PCM during nighttime when the cooling load is minimally needed and uses the stored thermal energy during the peak load hours by melting, or “charging” the PCM. This leads to better performance during peak load hours when higher cooling loads are needed. Different PCMs including Oleic acid, SP224A, CL, CaCl2.6H2O have been investigated. The... 

    Design and Analysis of a Simple Low-Power Network-on-Chip

    , M.Sc. Thesis Sharif University of Technology Gheibi Fetrat, Atiyeh (Author) ; Sarbazi Azad, Hamid (Supervisor) ; Hesabi, Shahin (Supervisor)
    The advancement of technology in the semiconductor industry and the resulting increase in the number of transistors on a chip has led to an increase in the number of processing cores an increase in the number of processing cores in a system on chip (SoC). A surge in the number of processing cores, makes their communication more and more noteworthy. This communication is established through the network on chip (NoC). One of the main challenges in NoC design is power management, as it constitutes a high percentage of the overall power consumption of the chip. One of the most power-hungry components of NoC is the router. According to our observation, some of the components of the routers are... 

    A comparative study of energy/power consumption in parallel decimal multipliers

    , Article Microelectronics Journal ; Vol. 45, Issue 6 , June , 2014 , pp. 775-780 Malekpour, A ; Ejlali, A ; Gorgin, S ; Sharif University of Technology
    Decimal multiplication is a frequent operation with inherent complexity in implementation. Commercial and financial applications require working with decimal numbers while it has been shown that if we convert decimal number to binary ones, this will negatively influence the preciseness required for these applications. Existing research works on parallel decimal multipliers have mainly focused on latency and area as two major factors to be improved. However, energy/power consumption is another prominent issue in today's digital systems. While the energy consumption of parallel decimal multipliers has not been addressed in previous works, in this paper we present a comparative study of... 

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

    , Article Proceedings - 2010 First Workshop on Hardware and Software Implementation and Control of Distributed MEMS, dMEMS 2010, 28 June 2010 through 29 June 2010, Besancon ; 2010 , Pages 86-91 ; 9780769540641 (ISBN) Najjari, N ; Sarbazi Azad, H ; Sharif University of Technology
    Networks on Chip1 have been proposed as a solution to mitigate complex on-chip communication problems. NoCs are composed of intellectual properties 2 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 on to 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 on to 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 to be... 

    Towards the optimal tracking interval management for target tracking wireless sensor networks

    , Article ATC 2009 - Proceedings of the 2009 International Conference on Advanced Technologies for Communications, 12 October 2009 through 14 October 2009 ; 2009 , Pages 161-166 ; 9781424451395 (ISBN) Jamali Rad, H ; Abolhassani, B ; Abdizadeh, M ; Sharif University of Technology
    We consider the minimization of power consumption in target tracking wireless sensor networks (WSNs) using dynamic modification of tracking interval. In this context, we first analyze the performance of such networks, using a quantitative mathematical analysis. Then we calculate an upper bound for the achievable improvement in total power consumption, when using an adaptive time interval modification algorithm for tracking moving objects with acceleration. Towards this optimum functionality, we propose a novel adaptive algorithm (AHC) to adapt the tracking interval such that it minimizes power consumption while keeping an acceptable accuracy. Simulation results show that using the proposed... 

    Effect of different traffic patterns on power consumption of sleep mode in the IEEE 802.16e MAC

    , Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 649-653 ; 1424410940 (ISBN); 9781424410941 (ISBN) Mohammadpour Nejatian, N ; Nayebi, M. M ; Ashtiani, F ; Sharif University of Technology
    In this paper, we study the effect of some traffic patterns on energy consumption for IEEE 802.16e nodes while operating in the sleep mode. In the sleep mode, a Mobile Subscribe Station (MSS) sleeps for a sleep interval and wakes up at the end of this interval in order to check buffered packet(s) at Base Station (BS) destined to it. If there is no packet, the MSS increases the sleep window up to the maximum value and sleeps again. For a more general traffic pattern, we evaluate the average power consumption. Based on our analysis, we conclude that traffic pattern plays an important role in power consumption. ©2007 IEEE  

    Evaluating and Improving the Reliability of Reversible Adiabatic Logic Styles

    , M.Sc. Thesis Sharif University of Technology Akbar, Reza (Author) ; Ejlali, Alireza (Supervisor)
    Adiabatic logic families are a group of logic circuits which operate based on adiabatic principles to tremendously reduce power consumption. These families have basic difference with common logic families in transistor level structure and there signals are not quadrangular but trapezoidal. Also, in these systems the source lines and clock pulse are the same. Research on Adiabatic families needs theoretical information in reversible computing. So we will start this project with explaining fundamental information in this field. After that some of these logic families are introduced and three important and widely used of them (SCRL-RERL-2LAL) are chosen to simulate. In each of these families... 

    Design of Soft Real-time Scheduler for Wireless Sensor Networks

    , M.Sc. Thesis Sharif University of Technology Seifoori, Zeinab (Author) ; Jahangir, Amir Hossein (Supervisor)
    Recent advances in miniaturization and low power design have led to a flurry of activity in wireless sensor networks (WSNs). Sensor networks have different constraints than traditional wired networks. A wireless sensor network is a special network with large numbers of nodes equipped with embedded processors, sensors, and radios. These nodes collaborate to accomplish a common task such as environment monitoring or asset tracking. Many of these applications interface with real world environments and delivery of data is subject to certain constraints. So It is often necessary for communication to meet real-time constraints. Most existing real-time protocols don’t use packet scheduling schemes... 

    Low-power technique for dynamic comparators

    , Article Electronics Letters ; Volume 52, Issue 7 , 2016 , Pages 509-511 ; 00135194 (ISSN) Khorami, A ; Sharifkhani, M ; Sharif University of Technology
    Institution of Engineering and Technology 
    A low-power technique to reduce the power consumption of the dynamic comparators is presented. Using this technique, the pre-ampli-fication phase of the comparator is stopped without any effect on the dynamic behaviour of the comparator. Therefore, the power consumption of the pre-amplifier stage which is the main part of the total power consumption is reduced significantly. Simulation results in various comparators reveal that the proposed technique reduces the total power consumption by more than 50%  

    Analysis of power control for indoor optical wireless CDMA networks using OOK and BPPM

    , Article IET Communications ; Volume 4, Issue 16 , November , 2010 , Pages 1919-1933 Khazraei, S. (Simin) ; Pakravan, M. R. (Mohammad Reza) ; Gohari, A ; Sharif University of Technology
    Wireless infrared optical code-division multiple access (W-OCDMA) is a new developing technique with many useful applications. Noting the limitation on power consumption and eye-safety requirements, wireless optical systems are power limited. Therefore control and efficient use of optical power is a key issue in analysis and design of these systems. Also, multi-user interference is the major source of impairment in these systems and power control is required to control and reduce this interference. Power control and the inevitable errors in its algorithms play an important role in design and implementation of these systems. In this article the authors study the uplink performance of W-OCDMA... 

    Introduction to non-volatile memory technologies

    , Article Advances in Computers ; Volume 118 , 2020 , Pages 1-13 Asadinia, M ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2020
    Dynamic Random Access Memory (DRAM) has been the leading main memory technology during the last four decades. In deep submicron regime, however, scaling DRAM comes with several challenges caused by charge leakage and imprecise charge placement. Phase Change Memory (PCM) technology is known as one of the most promising technologies to replace DRAM. Compared to competitive non-volatile memories like NAND Flash, Spin Transfer Torque random-access memory (STT-RAM), Magnetoresistive random-access memory (MRAM), PCM benefits from best attributes of fast random access, negligible leakage energy, superior scalability, high density, and operating in both Single-level Cell (SLC) and Multilevel Cell... 

    Reducing power consumption in NoC design with no effect on performance and reliability

    , Article 14th IEEE International Conference on Electronics, Circuits and Systems, ICECS 2007, Marrakech, 11 December 2007 through 14 December 2007 ; 2007 , Pages 886-889 ; 1424413788 (ISBN); 9781424413782 (ISBN) Patooghy, A ; Fazeli, M ; Miremadi, S. G ; Sharif University of Technology
    High reliability, low power consumption and high performance are key objectives in the design of NoCs. These three design objectives should be considered simultaneously in order to have an optimal design. This paper proposes a method to reduce power consumption of an application specific NoC. This is done in two steps: 1) Extra virtual channels are used in the router architecture to increase the performance in an application specific NoC, and 2) The amount of the performance gain is then set to the initial point using frequency scaling technique, hence reducing the power consumption, without corruption of reliability. The simulation results show that the method can reduce the power... 

    A stochastic DVS-based dynamic power management for soft real-time systems

    , Article 2005 International Conference on Wireless Networks, Communications and Mobile Computing, Maui, HI, 13 June 2005 through 16 June 2005 ; Volume 1 , 2005 , Pages 63-68 ; 0780393058 (ISBN); 9780780393059 (ISBN) Kargahi, M ; Movaghar, A ; Sharif University of Technology
    This paper introduces a stochastic dynamic power management policy for soft real-time systems which uses DVS to consume less power in the main processor while satisfying the performance constraints. The idea is based on a Markovian model of the system. The system under study is a single. processor system with real-time jobs which arrive according to a Poisson process and have exponentially distributed deadlines and service times. Since the speed levels in real processors are not continuous, the required service rate for a given performance is estimated in a probabilistic manner using its two immediate neighboring speeds. Experimental results show that the long run power consumption of the...