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3RSeT: Read disturbance rate reduction in STT-mram caches by selective tag comparison
, Article IEEE Transactions on Computers ; 2021 ; 00189340 (ISSN) ; Farbeh, H ; Asadi, H ; Sharif University of Technology
IEEE Computer Society
2021
Abstract
Recent development in memory technologies has introduced Spin-Transfer Torque Magnetic RAM (STT-MRAM) as the most promising replacement for SRAMs in on-chip cache memories. Besides its lower leakage power, higher density, immunity to radiation-induced particles, and non-volatility, an unintentional bit flip during read operation, referred to as read disturbance error, is a severe reliability challenge in STT-MRAM caches. One major source of read disturbance error in STT-MRAM caches is simultaneous accesses to all tags for parallel comparison operation in a cache set, which has not been addressed in previous work. This paper first demonstrates that high read accesses to tag arrays extremely...
3RSeT: Read disturbance rate reduction in STT-MRAM caches by selective tag comparison
, Article IEEE Transactions on Computers ; Volume 71, Issue 6 , 2022 , Pages 1305-1319 ; 00189340 (ISSN) ; Farbeh, H ; Asadi, H ; Sharif University of Technology
IEEE Computer Society
2022
Abstract
Recent development in memory technologies has introduced Spin-Transfer Torque Magnetic RAM (STT-MRAM) as the most promising replacement for SRAMs in on-chip cache memories. Besides its lower leakage power, higher density, immunity to radiation-induced particles, and non-volatility, an unintentional bit flip during read operation, referred to as read disturbance error, is a severe reliability challenge in STT-MRAM caches. One major source of read disturbance error in STT-MRAM caches is simultaneous accesses to all tags for parallel comparison operation in a cache set, which has not been addressed in previous work. This article first demonstrates that high read accesses to tag array extremely...
A combination of MADM and genetic algorithm for optimal DG allocation in power systems
, Article 42nd International Universities Power Engineering Conference, UPEC 2007, Brighton, 4 September 2007 through 6 September 2007 ; 2007 , Pages 1031-1035 ; 1905593368 (ISBN); 9781905593361 (ISBN) ; Afsharnia, S ; Khodayar, M. E ; Rahimikian, A ; Sharbafi, M. A ; Sharif University of Technology
2007
Abstract
Distributed Generation (DG) can help in reducing the cost of electricity to the customer, relieve network congestion, provide environmentally friendly energy close to load centers as well as promote system technical characteristics such as loss reduction, voltage profile enhancement, reserve mitigation and many other factors. Furthermore, its capacity is also scalable and it can provide voltage support at distribution level. The planning studies include penetration level and placement evaluation which are influenced directly by DG type. Most of the previous publications in this field chose one or two preferred parameter as basic objective and implement the optimizations in systems. But due...
A cyber-physical system for building automation and control based on a distributed MPC with an efficient method for communication
, Article European Journal of Control ; Volume 61 , 2021 , Pages 151-170 ; 09473580 (ISSN) ; Farhadi, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
This paper introduces a cyber-physical system for building automation and control that is developed based on a distributed model predictive control. The implemented distributed method significantly reduces computation overhead with respect to the centralized methods. However, continuous data transfer between subsystems, which are often far from each other, is required when using this method. Information transmission between subsystems is very often subject to the limitations of transmission bandwidth and/or short communication range resulting in significant communication overhead. This causes significant time latency between making measurements and applying control commands, which adversely...
Aging aircraft cost analysis using system dynamics modeling
, Article 29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014 ; 7-12 September , 2014 ; ISBN: 3932182804 ; Shadaab, N ; Abedian, A ; Tanara, A. K ; Sharif University of Technology
Abstract
Ways to reduce an airline's cost has been studied for years. In fact, in order to achieve this goal, ones need to know different types of airline's costs including; fuel and oil, maintenance, Ticketing, passenger services, etc. and their impact on the total cost of an airline. According to announcement of ICAO [1], "maintenance cost (about 11% of total cost) is the second major cost after fuel and oil". Therefore, this may attract airline owners' attention to find ways to control maintenance cost and eventually the total cost of an airline. Though, there are many systematic approaches to analyze cost reduction and making policies, in this article, SD modeling is applied to develop a...
A graph weighting method for reducing consensus time in random geographical networks
, Article 24th IEEE International Conference on Advanced Information Networking and Applications Workshops, WAINA 2010, 20 April 2010 through 23 April 2010, Perth ; 2010 , Pages 317-322 ; 9780769540191 (ISBN) ; Sharif University of Technology
2010
Abstract
Sensor networks are increasingly employed in many applications ranging from environmental to military cases. The network topology used in many sensor network applications has a kind of geographical structure. A graph weighting method for reducing consensus time in random geographical networks is proposed in this paper. We consider a method based on the mutually coupled oscillators for providing general consensus in the network. In this way, one can relate the consensus time to the properties of the Laplacian matrix of the connection graph, i.e. to the second smallest eigenvalue (algebraic connectivity). Our weighting algorithm is based on the node and edge between centrality measures. The...
A heuristic trade off model for integration of distributed generations in deregulated power systems considering technical, economical and environmental issues
, Article 2008 IEEE 2nd International Power and Energy Conference, PECon 2008, Johor Baharu, 1 December 2008 through 3 December 2008 ; 2008 , Pages 1275-1279 ; 9781424424054 (ISBN) ; Nasiri, R ; Bagheri, M ; Tehrani, A. A ; Sharif University of Technology
2008
Abstract
With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within...
A model for stochastic planning of distribution network and autonomous DG units
, Article IEEE Transactions on Industrial Informatics ; Volume 16, Issue 6 , August , 2020 , Pages 3685-3696 ; Farzin, H ; Abbaspour, A ; Fotuhi-Firuzabad, M ; Lehtonen, M ; Sharif University of Technology
IEEE Computer Society
2020
Abstract
This article presents a mixed-integer linear stochastic model for the optimal expansion planning of electricity distribution networks and distributed generation (DG) units. In the proposed framework, autonomous DG units are aggregated and modeled using the well-known energy hub concept. In this model, the uncertainties of heat and electricity demand as well as renewable generation are represented using various scenarios. Although this is a standard technique to capture the uncertainties, it drastically increases the dimensions of this optimization problem and makes it practically intractable. In order to address this issue, a novel iterative method is developed in this article to enhance the...
An adaptive approach for PEVs charging management and reconfiguration of electrical distribution system penetrated by renewables
, Article IEEE Transactions on Industrial Informatics ; 2017 ; 15513203 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
Abstract
An adaptive approach for distribution system reconfiguration and charging management of plug-in electric vehicles (PEV) is presented in this study. A stochastic model predictive control is applied to stochastically, adaptively, and dynamically reconfigure the system, manage the incidental charging pattern of PEVs, and deal with the variable and uncertain power of renewable energy sources. The objective function of problem is minimizing daily operation cost of system. Herein, the geography of area is considered and the behavior of PEVs' drivers (based on their income level) is modeled with respect to the value of incentive and their hourly distance from each charging station. It is shown that...
An adaptive approach for PEVs charging management and reconfiguration of electrical distribution system penetrated by renewables
, Article IEEE Transactions on Industrial Informatics ; Volume 14, Issue 5 , May , 2018 , Pages 2001-2010 ; 15513203 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
IEEE Computer Society
2018
Abstract
An adaptive approach for distribution system reconfiguration and charging management of plug-in electric vehicles (PEV) is presented in this study. A stochastic model predictive control is applied to stochastically, adaptively, and dynamically reconfigure the system, manage the incidental charging pattern of PEVs, and deal with the variable and uncertain power of renewable energy sources. The objective function of problem is minimizing daily operation cost of system. Herein, the geography of area is considered and the behavior of PEVs' drivers (based on their income level) is modeled with respect to the value of incentive and their hourly distance from each charging station. It is shown that...
An efficient and low power one-lambda crosstalk avoidance code design for network on chips
, Article Microprocessors and Microsystems ; Volume 63 , 2018 , Pages 36-45 ; 01419331 (ISSN) ; Mahdavi, Z ; Sharif University of Technology
Abstract
Crosstalk faults occurring in wires of Networks on Chip (NoCs) can seriously threaten the reliability of data transfer. One efficient way to tackle crosstalk faults is numeral-based Crosstalk Avoidance Codes (CACs). Numeral-based CACs reduce crosstalk faults by preventing specific transition patterns to occur. One-Lambda Codes (OLCs) are the most efficient types of CACs. However, the codec of OLCs imposes overheads including power consumption, critical path and area occupation to the routers of NoCs. To find overhead-efficient OLCs, this paper proposes an Algorithm for Generating OLC Numeral systems (AGON). AGON provides a tradeoff for designers in selecting overhead-efficient OLCs. Using...
An efficient method for identifying IDS agent nodes by discovering compromised nodes in MANET
, Article 2009 International Conference on Computer and Electrical Engineering, ICCEE 2009, 28 December 2009 through 30 December 2009, Dubai ; Volume 1 , 2009 , Pages 625-629 ; 9780769539256 (ISBN) ; Khavasi, A. A ; Movaghar, A ; Sharif University of Technology
Abstract
Intrusion Detection Systems (IDS) for Mobile Ad hoc NETworks (MANETs) are necessary when they are deployed in reality. In This paper, we have presented a combined method of selecting IDS agent nodes in mobile ad hoc networks. Since, the IDS agents in MANET due to more activities need to more battery power. In our method, first, compromised nodes are detected and then the nodes with the highest energy power from among valid nodes as IDS agent nodes are considered. So, with this method, some valid nodes contribute in intrusion detection activities and costs of the network monitoring will be reduced and the network lifetime will be increased. © 2009 IEEE
An enterprise-grade open-source data reduction architecture for all-flash storage systems
, Article Proceedings of the ACM on Measurement and Analysis of Computing Systems ; Volume 6, Issue 2 , 2022 ; 24761249 (ISSN) ; Raaf, P ; Kishani, M ; Salkhordeh, R ; Asadi, H ; Brinkmann, A ; Sharif University of Technology
Association for Computing Machinery
2022
Abstract
All-flash storage (AFS) systems have become an essential infrastructure component to support enterprise applications, where sub-millisecond latency and very high throughput are required. Nevertheless, the price per capacity ofsolid-state drives (SSDs) is relatively high, which has encouraged system architects to adoptdata reduction techniques, mainlydeduplication andcompression, in enterprise storage solutions. To provide higher reliability and performance, SSDs are typically grouped usingredundant array of independent disk (RAID) configurations. Data reduction on top of RAID arrays, however, adds I/O overheads and also complicates the I/O patterns redirected to the underlying backend SSDs,...
A new designed linear Fresnel lens solar concentrator based on spectral splitting for passive cooling of solar cells
, Article Energy Conversion and Management ; Volume 230 , 2021 ; 01968904 (ISSN) ; Saboohi, Y ; Moshfegh, A. Z ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The use of solar concentrators can be an alternative for initial cost reduction in the PV systems. However, they suffer from high cell temperature that can be overcome by different active or passive cooling approaches. Spectral splitting and the elimination of high-energy solar photons are effective solutions for cell temperature reduction. In this study, we developed a Polymethyl methacrylate Spectral Splitting Fresnel Lens (SSFL) for linear concentration using a new design, which directs the desired portion of the spectrum towards the cell and diffracts the rest to eliminate the use of beam splitters or nanofluids in the spectral splitting system. Different SSFLs were considered for...
An integrated vendor-buyer inventory model with partial backordering
, Article Journal of Manufacturing Technology Management ; Volume 23, Issue 7 , 2012 , Pages 869-884 ; 1741038X (ISSN) ; Jokar, M. R. A ; Sharif University of Technology
2012
Abstract
Purpose - The purpose of this paper is to analyze the effects of supply chain coordination on inventory management while the retailer inventory cycle consists of a shortage period and the backorder rate linearly decreases as a function of shortage duration. It is intended to consider how on-hand inventory and shortage durations are altered when the decisions are centralized. Design/methodology/approach - Mathematical modelling of inventory costs for the retailer and the vendor is used to formulate objective functions. The vendor sets his inventory period as an integer multiple (n) of the retailer inventory cycle in which the integer multiple is a decision variable. Solution spaces of models...
An investigation of vendor-managed inventory application in supply chain: The EOQ model with shortage
, Article International Journal of Advanced Manufacturing Technology ; Volume 49, Issue 1-4 , July , 2010 , Pages 329-339 ; 02683768 (ISSN) ; Akhavan Niaki, S. T ; Roozbeh Nia, A ; Sharif University of Technology
2010
Abstract
Recent researches have shown the importance of improving the supply chain competitiveness by means of strategic alliances. This study considers the retailer-supplier partnership through a vendor-managed inventory (VMI) system and develops an analytical model to explore the effect of important supply chain parameters on the cost savings realized from collaborative initiatives. This model is developed for a two-level supply chain consisting of a single supplier and a single retailer and examines the inventory management practices before and after implementation of VMI. The results of analytical examination show that VMI implementation in economic order quantity model when shortage is...
An nnovative test bed for verification of attitude control system
, Article IEEE Aerospace and Electronic Systems Magazine ; Volume 32, Issue 6 , 2017 , Pages 16-22 ; 08858985 (ISSN) ; Faghihinia, A ; Kalhor, A ; Sharif University of Technology
Abstract
A 3 DOF platform was constructed in the Georgia Institute of Technology to perform new control strategies in an experimental framework. Also in this simulator, there isn't any sensor used by a real satellite for attitude determination. The setup was structured on data transmitting and synchronization of distributed elements for ADCS tests. In such a plan, not only can different elements of the test bed be used individually, but also they can support an integrated hardware in the loop test. Accordingly, reusing the hardware sources causes a cost reduction of development. Furthermore the geometric interferences of different parts are minimized in this plan. So, the test bed can be developed...
Annual comparative performance and cost analysis of high temperature, sensible thermal energy storage systems integrated with a concentrated solar power plant
, Article Solar Energy ; Volume 153 , 2017 , Pages 153-172 ; 0038092X (ISSN) ; Taylor, R. A ; Nithyanandam, K ; Shafiei Ghazani, A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
The present study conducts a comprehensive comparative techno-economic analysis of some near-term sensible thermal energy storage (TES) alternatives to the ‘standard’ two-tank molten salt system for concentrated solar power (CSP) plants. As such, we conducted detailed, relative annual transient simulations for single-medium thermocline (SMT), dual-media thermocline (DMT), and shell-and-tube (ST) systems. To be consistent with recent literature, the DMT and ST systems use concrete with a porosity of 0.2 (e.g. where concrete occupies 80% of the system) as their low cost filler material. The systems were integrated into a validated 19.9 MWe Gemasolar CSP model, which has a solar multiple of...
A novel BEM- based channel estimation algorithm for time variant uplink OFDMA system
, Article International Conference on Advanced Communication Technology, ICACT, 7 February 2010 through 10 February 2010 ; Volume 2 , Feb , 2010 , Pages 1289-1293 ; 17389445 (ISSN) ; 9788955191455 (ISBN) ; Tabatabavakili, V ; Samsami Khodadad, F ; Hosseinnezhad, M ; Safaei, A ; Sharif University of Technology
2010
Abstract
IN this paper the effect of different channel estimation approaches in OFDMA uplink system which are based on Basis Expansion Model (BEM) and widely used to consider time varying channels are discussed. It has been shown in previous works that modeling error will be reduced by applying oversampled BEM with cost of increasing sensitivity to noise. This problem will be solved by combining oversampled BEM and MMSE channel estimator with cost of increasing computational complexity. In this paper a novel channel estimation approach is represented in which by combining oversampled BEM and low rank MMSE in frequency domain, almost the same performance as the full rank MMSE has been achieved while...
A novel optimal distribution system planning framework implementing distributed generation in a deregulated electricity market
, Article Electric Power Systems Research ; Volume 80, Issue 7 , July , 2010 , Pages 828-837 ; 03787796 (ISSN) ; Poure, P ; Abbaspour Tehrani fard, A ; Saadate, S ; Sharif University of Technology
2010
Abstract
This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system...