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energy-utilization
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Real time probabilistic power system state estimation
, Article International Journal of Electrical Power and Energy Systems ; Vol. 62, issue , 2014 , p. 383-390 ; ISSN: 1420615 ; Rashidinejad, M ; Kouhi, S ; Fotuhi-Firuzabad, M ; Ravadanegh, S.N ; Sharif University of Technology
Abstract
Smartening of contemporaneous power delivery systems in conjunction with the increased penetration of renewable energies (REs), change the way to energize consumers who are willing to maximize their utility from energy consumption. However, there is a high degree of uncertainty in the electricity markets of such systems. Moreover, the unprecedented ascending penetration of distributed energy resources (DERs) mainly harvesting REs is a direct consequence of environmentally friendly concerns. This type of energy resources brings about more uncertainties into power system operation resulting in, necessitates probabilistic analysis of the system performance. In the smarter power markets,...
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 ; Fotuhi-Firuzabad, M ; Rastegar, M ; Sharif University of Technology
Abstract
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...
Impacts of plug-in hybrid electric vehicle uncertainty and grid unavailability on home load management
, Article 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings ; 2012 , p. 693-698 ; ISBN: 9781460000000 ; Safdarian, A ; Fotuhi-Firuzabad, M ; Aminifar, F ; Sharif University of Technology
Abstract
A massive focus has recently been made on demand response (DR) programs, aimed to the electricity price reduction, reliability improvement, and energy efficiency. Basically, DR programs are divided into twofold main categories, namely incentive-based programs and price- or time-based programs. The focus of this paper is on priced-based DR programs including consumer responses to the time differentiated pricing. Home load management (HLM) program is designed to control responsive appliances and charging/discharging cycles of plug-in hybrid electric vehicles (PHEVs) by the consumer. Uncertain parameters associated with PHEV, i.e. its departure/travelling time and energy consumption as well as...
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 ; Sarbazi-Azad, H ; Sharif University of Technology
Abstract
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...
Multicast-aware mapping algorithm for on-chip networks
, Article Proceedings - 19th International Euromicro Conference on Parallel, Distributed, and Network-Based Processing, PDP 2011 ; 2011 , p. 455-462 ; ISBN: 9780769543284 ; Arjomand, M ; Sarbazi-Azad, H ; Sharif University of Technology
Abstract
Networks-on-Chip (NoCs for short) are known as the most scalable and reliable on-chip communication architectures for multi-core SoCs with tens to hundreds IP cores. Proper mapping the IP cores on NoC tiles (or assigning threads to cores in chip multiprocessors) can reduce end-to-end delay and energy consumption. While almost all previous works on mapping consider higher priority for the application's flows with higher required bandwidth, a mapping strategy, presented in this paper, is introduced that considers multicast communication flows in addition to the normal unicast flows. To this end, multicast and unicast traffic flows are first characterized in terms of some new metrics which are...
Improving the performance of deadlock recovery based routing in irregular mesh NoCs using added mesh-like links
, Article ISCAS 2010 - 2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems ; 2010 , p. 3236-3239 ; ISBN: 9781424453085 ; Ahmadian, A. S ; Sarbazi-Azad, H ; Sharif University of Technology
Abstract
Heterogeneity is one of the challenges in the current NoC design which forces designers to consider irregular topologies. Therefore, finding an optimal topology with minimum cost (minimum use of links, buffers, NIs, etc) and power consumption, and maximum flexibility can provide the best cost-performance trade-off. Irregular mesh is a topology which combines the benefits of regularity and advantage of irregularity. Routing algorithms especially those coupled with wormhole switching should deal with deadlock occurrences. Unlike deadlock avoidance-based schemes, deadlock detection and recovery-based routing schemes, do not restrict routing adaptability. In this paper, we modify irregular mesh...
A comparison between the minimum-order & full-order observers in robust control of the air handling units in the presence of uncertainty
, Article Energy and Buildings ; Volume 91 , 15 March , 2015 , Pages 115-130 ; ISSN: 3787788 ; Moradi, H ; Alasty, A ; Sharif University of Technology
Abstract
Control of the air-handling units (AHU) is required to maintain satisfactory comfort conditions with low energy consumption. In the case of failure in sensor fusion systems of AHUs, full-order observers can be used as the supportive tool to provide an acceptable estimation of state variables. In this paper, a multivariable nonlinear model of the AHU is considered in the presence of uncertainties. The indoor temperature and relative humidity are controlled via manipulation of valve positions of air and cold water flow rates. In proposed hybrid control system, full and minimum-order observers are designed for the estimation of indoor temperature and relative humidity. Also, a regulator for...
Nonlinear dynamics, bifurcation and performance analysis of an air-handling unit: Disturbance rejection via feedback linearization
, Article Energy and Buildings ; Vol. 56 , 2013 , pp. 150-159 ; ISSN: 03787788 ; Saffar-Avval, M ; Alasty, A ; Sharif University of Technology
Abstract
Nowadays, dynamic analysis of air-conditioner units is essential to achieve satisfactory comfort conditions in buildings with low energy consumption and operation cost. In this paper, a nonlinear multi input-multi output model (MIMO) of an air-handling unit (AHU) is considered. In the presence of realistic harmonic disturbances, nonlinear dynamics of AHU is investigated. The effect of various thermodynamics and geometrical parameters on limit cycles behaviour of the indoor temperature is investigated. It is observed that the indoor space volume plays as the bifurcation parameter of the system. Decreasing the indoor space volume leads to the occurrence of secondary Hopf (Neimark) bifurcation...
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 ; Salehi, R ; Alasty, A ; Sharif University of Technology
Abstract
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...
Power-efficient prefetching on GPGPUs
, Article Journal of Supercomputing ; Volume 71, Issue 8 , August , 2015 , pp. 2808-2829 ; ISSN: 09208542 ; Hessabi, S ; Abdi, M ; Baniasadi, A ; Sharif University of Technology
Abstract
The graphics processing unit (GPU) is the most promising candidate platform for achieving faster improvements in peak processing speed, low latency and high performance. The highly programmable and multithreaded nature of GPUs makes them a remarkable candidate for general purpose computing. However, supporting non-graphics computing on graphics processors requires addressing several architectural challenges. In this paper, we focus on improving performance by better hiding long waiting time for transferring data from the slow global memory. Furthermore, we show that the proposed method can reduce power and energy. Reduction in access time to off-chip data has a noticeable role in reducing...
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 ; Khansari, M ; Rabiee, H. R ; Salehi, M ; Sharif University of Technology
Abstract
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...
A comparative study of energy/power consumption in parallel decimal multipliers
, Article Microelectronics Journal ; Vol. 45, Issue 6 , June , 2014 , pp. 775-780 ; Ejlali, A ; Gorgin, S ; Sharif University of Technology
Abstract
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...
Energy efficient and high speed error control scheme for real time wireless sensor networks
, Article International Journal of Distributed Sensor Networks ; Vol. 2014 , 2014 ; Movaghar, A ; Sabaei, M ; Sharif University of Technology
Abstract
Reliability and energy consumption are two of the main constraints in wireless sensor networks (WSNs). In this paper, a novel energy efficient and high speed error control scheme is introduced that is based on the Redundant Residue Number System (RRNS) allowing real-time application of WSNs. The proposed approach employs a new 3-moduli set {22n+1, 2 2n1-1, 2n- 1 } and an efficient reverse converter which relies on the Mixed Radix Conversion (MRC) algorithm and achieves significant improvements both in terms of conversion delay and hardware design. In order to obtain error controllability, two-redundant-moduli set 23n+1 - 1, 24n+1 - 1 is also added to the main 3-moduli set. The theoretical...
All-optical wavelength-routed architecture for a power-efficient network on chip
, Article IEEE Transactions on Computers ; Vol. 63, issue. 3 , 2014 , p. 777-792 ; Hessabi, S ; Sharif University of Technology
Abstract
In this paper, we propose a new architecture for nanophotonic Networks on Chip (NoC), named 2D-HERT, which consists of optical data and control planes. The proposed data plane is built upon a new topology and all-optical switches that passively route optical data streams based on their wavelengths. Utilizing wavelength routing method, the proposed deterministic routing algorithm, and Wavelength Division Multiplexing (WDM) technique, the proposed data plane eliminates the need for optical resource reservation at the intermediate nodes. For resolving end-point contention, we propose an all-optical request-grant arbitration architecture which reduces optical losses compared to the alternative...
Analytical leakage-aware thermal modeling of a real-time system
, Article IEEE Transactions on Computers ; Vol. 63, issue. 6 , 2014 , pp. 1377-1391 ; ISSN: 00189340 ; Kargahi, M ; Movaghar, A ; Sharif University of Technology
Abstract
We consider a firm real-time system with a single processor working in two power modes depending on whether it is idle or executing a job. The system is equipped with dynamic thermal management through a cooling subsystem which can switch between two cooling modes. Real-time jobs which arrive to the system have stochastic properties and are prone to soft errors. A successful job is one that enters the system and completes its execution with no timing or soft error. Appropriateness of the system is evaluated based on its performance, temperature behavior, reliability, and energy consumption. It is noteworthy that these criteria have mutual interactions to each other: the stochastic nature of...
An energy-efficient multi-sensor scheduling mechanism with QoS support for WBANs
, Article IEEE Wireless Communications and Networking Conference, WCNC ; 2014 , pp. 1703-1708 ; ISSN: 15253511 ; Ashtiani, F ; Javidi, T ; Nasiri-Kenari, M ; Vahdat, B. V ; Sharif University of Technology
Abstract
In wireless body area networks (WBANs) it is necessary to devise an energy-efficient MAC scheduling mechanism which is capable of meeting strict QoS requirements. In this paper, special characteristics of WBAN channels, namely, the slow fading, the periodicity of fading, and the correlation among the channels have been exploited to formulate the sensor scheduling problem as a partially observable Markov decision problem (POMDP). Specific algorithms based on value iteration and pruning have been proposed in order to reduce the computational burden associated with the corresponding POMDP. The proposed scheduling mechanism is compared against a TDMA scheduling for a three-sensor network, and an...
An auto-calibrated, dual-mode SRAM macro using a hybrid offset-cancelled sense amplifier
, Article Microelectronics Journal ; Vol. 45, issue. 6 , 2014 , p. 781-792 ; Sharifkhani, M ; Sharif University of Technology
Abstract
A dual-mode power and performance optimized SRAM is presented. Given the fact that the power and speed associated with the cell access time are directly related to the sense amplifier offset a new optimization platform based on the hybrid offset-cancelled current sense amplifier (OCCSA) [1] is presented. It is shown that the speed and power overhead of the offset cancellation can be optimized in a multi-variable auto-calibration loop to achieve the lowest power or the highest performance mode. The flexibility of having two degrees of freedom in OCCSA offers a significant bitline delay reduction with minimum power sacrifice in the high performance mode. The proposed scheme is verified using a...
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 ; Saboohi, Y ; Sharif University of Technology
Abstract
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...
Decision support-as-a-service: An energy-aware decision support service in cloud computing
, Article IKT 2013 - 2013 5th Conference on Information and Knowledge Technology ; 2013 , Pages 71-76 ; 9781467364904 (ISBN) ; Ebrahimirad, V ; Yazdani, N ; Sharif University of Technology
2013
Abstract
Cloud Computing has become popular nowadays. Cloud providers with scalable infrastructures can offer cloud-based services which reduce investment of organizations and diminish most of their operational costs. Therefore, traditional services need to be renovated in the spirit of cloud environments. In this paper, Decision Support-as-a-Service (DSaaS) which is a cloud-based decision support system is introduced. The DSaaS can help managers to make fast and precise decisions. Also, the important challenges of such a system are discussed and a proper energy-aware resource allocation policy is proposed as the solution for the main challenge. A wide range of simulation results show that the policy...
Finding assignable cause in medium voltage network by statistical process control
, Article IET Conference Publications ; Volume 2013, Issue 615 CP , 2013 ; 9781849197328 (ISBN) ; Mirzavand, M ; Mahdloo, F ; Sharif University of Technology
2013
Abstract
The current of outgoing feeders are very important data transmitted over SCADA system. Monitoring of these currents can help dispatching engineers to detect abnormality in energy consumption trend and minor faults in distribution network. Statistical process control (SPC) is one of the capable approaches which can be used for this purpose. Statistical process control is based on categorizing variations into assignable causes and random causes. In current paper we described the methods which were used for finding assignable causes in load trend and short time load variation in Alborz province power distribution company pilot project. Although this approach is not developed completely and some...