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energy-efficiency
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Ultrasonic ion pumps in bio-battery's electrolyte
, Article Advanced Materials Research, 7 January 2012 through 8 January 2012 ; Volume 463-464 , January , 2012 , Pages 909-913 ; 10226680 (ISSN) ; 9783037853634 (ISBN) ; Ebrahimi, A ; Sherafati, A ; Khalilgharibi, N ; Zand, M. K ; Dibazar, M. S. S ; Sobhani, S. O ; Sharif University of Technology
2012
Abstract
Bio-batteries are environmental friendly electricity generation devices that utilize energy from biological sources, like glucose[1] [2]. It consists of an anode with digesting enzymes and a cathode comprising oxygen-reducing enzymes. Immobilizing enzymes is a considerable issue in these kinds of devices. In this article, we propose two new methods for immobilizing and shifting particles likewise enzymes used in bio-batteries towards the anode or cathode end. Our experiments illustrate how tiny particles could be trapped in the nodes of the ultrasonic standing waves and by two methods of displacing the nodes, we can transfer the particles towards a desired location. First method is based on...
Long lifetime real-time routing in unreliable wireless sensor networks
, Article IFIP Wireless Days ; Volume 1, Issue 1 , 2011 ; 21569711 (ISSN); 9781457720277 (ISBN) ; Yousefi, H ; Yeganeh, M. H ; Movaghar, A ; Sharif University of Technology
Abstract
Lifetime is the mos important concern in Wireless Sensor Networks (WSNs) due to limited battery power of sensor nodes. Moreover, a WSN should be capable of timely fulfilling its mission without losing important information in event-critical applications. In this paper, we focus on designing an energy-efficient and energy-aware real-time routing algorithm aiming to explore the long lifetime routing schemes in which delay constraint is satisfied in the presence of lossy communication links. To achieve this goal, our energy-aware forwarding protocol utilizes an optimum distance real-time routing algorithm to minimize energy consumption in unreliable WSNs. Simulation results reveal that the...
Queen-bee algorithm for energy efficient clusters in wireless sensor networks
, Article World Academy of Science, Engineering and Technology ; Volume 73 , 2011 , Pages 1080-1083 ; 2010376X (ISSN) ; Barati, A ; Movaghar, A ; Sharif University of Technology
Abstract
Wireless sensor networks include small nodes which have sensing ability; calculation and connection extend themselves everywhere soon. Such networks have source limitation on connection, calculation and energy consumption. So, since the nodes have limited energy in sensor networks, the optimized energy consumption in these networks is of more importance and has created many challenges. The previous works have shown that by organizing the network nodes in a number of clusters, the energy consumption could be reduced considerably. So the lifetime of the network would be increased. In this paper, we used the Queen-bee algorithm to create energy efficient clusters in wireless sensor networks....
An energy-efficient virtual channel power-gating mechanism for on-chip networks
, Article Proceedings -Design, Automation and Test in Europe, DATE, 9 March 2015 through 13 March 2015 ; Volume 2015-April , March , 2015 , Pages 1527-1532 ; 15301591 (ISSN) ; 9783981537048 (ISBN) ; Sadrosadati, M ; Fakhrzadehgan, A ; Modarressi, M ; Sarbazi Azad, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Power-gating is a promising method for reducing the leakage power of digital systems. In this paper, we propose a novel power-gating scheme for virtual channels in on-chip networks that uses an adaptive method to dynamically adjust the number of active VCs based on the on-chip traffic characteristics. Since virtual channels are used to provide higher throughput under high traffic loads, our method sets the number of virtual channel at each port selectively based on the workload demand, thereby do not negatively affect performance. Evaluation results show that by using this scheme, about 40% average reduction in static power consumption can be achieved with negligible performance overhead
Server consolidation techniques in virtualized data centers: a survey
, Article IEEE Systems Journal ; Volume 11, Issue 2 , 2017 , Pages 772-783 ; 19328184 (ISSN) ; Goudarzi, M ; Sharif University of Technology
Abstract
Data centers and their applications are exponentially growing. Consequently, their energy consumption and environmental impacts have also become increasingly more important. Virtualization technologies are widely used in modern data centers to ease the management of the data center and to reduce its energy consumption. Data centers that employ virtualization technologies are typically called virtualized or cloud data centers. Virtualization technologies enable virtual machine (VM) live migration, which allows the VMs to be freely moved among physical machines (PMs) with negligible downtime. Thus, several VMs can be packed on a single PM so as to let the PM run in its more energy-efficient...
An accurate low-power DAC for SAR ADCs
, Article 59th IEEE International Midwest Symposium on Circuits and Systems, MWSCAS 2016, 16 October 2016 through 19 October 2016 ; 2017 ; 15483746 (ISSN); 9781509009169 (ISBN) ; Khorami, A ; Sharifkhani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
A highly energy-efficiency switching procedure for the capacitor-splitting digital-To-Analog converter (DAC) is presented for successive approximation register (SAR) analogue-To-digital converters (ADCs). In this procedure, the MSB capacitor is divided into its binary constituents. All output digital bits, except the least significant bit (LSB), is determined using reference voltage (Vref), while the common-mode voltage (Vcm) is used to determine the LSB. Therefore, the precision of the proposed SAR ADC is independent of the precision of Vcm except in the LSB. This method reduces the area by 75% compared to the conventional binary weighted DAC and reduces the switching energy by 96.89%. ©...
Assessing swedish foundries energy management program
, Article Energies ; Volume 11, Issue 10 , 2018 ; 19961073 (ISSN) ; Thollander, P ; Cagno, E ; Rafiee, M ; Sharif University of Technology
Abstract
With regard to increased sustainability, managers not only need to know WHAT is needed for their company to improve, but also HOW to do so in detail is equally important. Energy management (EnM) is a pillar to the transformation of industrial energy systems towards enhanced energy efficiency and increased sustainability. One way to develop more and improve EnM both practically and theoretically is to shed light on how the combination of techniques and operation can contribute to successful EnM. This paper, therefore, through investigation of 10 Swedish foundries aims to present the structure of the energy strategy and associated practices at first; second, to assess industry’s EnM program...
Energy efficient cultivation of microalgae using phosphorescence materials and mirrors
, Article Sustainable Cities and Society ; Volume 41 , 2018 , Pages 449-454 ; 22106707 (ISSN) ; Shafii, M. B ; Roshandel, R ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In the present study, two novel annular photobioreactors (PBR) were developed to enhance microalgae growth. One of these photobioreactors used mirrors outside the PBR, while the other one utilized phosphorescence materials inside the PBR. The results of the study suggested that the use of mirrors and phosphorescence materials led to 70% and 30% increase, respectively, in the light intensity without any additional energy consumption. Further, the results revealed that when compared with the base case, the biomass concentration increased by 91% and 24% in PBR with mirrors and phosphorescence materials, respectively. In conclusion, an improvement in PBRs resulted in efficient light to biomass...
Domino cache: an energy-efficient data cache for modern applications
, Article ACM Transactions on Design Automation of Electronic Systems ; Volume 23, Issue 3 , April , 2018 ; 10844309 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
Association for Computing Machinery
2018
Abstract
The energy consumption for processing modern workloads is challenging in data centers. Due to the large datasets of cloudworkloads, the miss rate of the L1 data cache is high, andwith respect to the energy efficiency concerns, suchmisses are costly formemory instructions because lower levels ofmemory hierarchy consume more energy per access than the L1. Moreover, large last-level caches are not performance effective, in contrast to traditional scientific workloads. The aim of this article is to propose a large L1 data cache, called Domino, to reduce the number of accesses to lower levels in order to improve the energy efficiency. In designing Domino, we focus on two components that use the...
Fault tolerant and low energy write-back heterogeneous set associative cache for DSM technologies
, Article International Conference on Availability, Reliability and Security, ARES 2009, Fukuoka, Fukuoka Prefecture, 16 March 2009 through 19 March 2009 ; 2009 , Pages 448-453 ; 9780769535647 (ISBN) ; Ejlali, A ; Miremadi, S. G ; Sharif University of Technology
2009
Abstract
This paper presents a fault tolerant and energy efficient write-back set-associative cache, which has a heterogeneous structure. The cache architecture is based on partitioning the ways of each set into two different parts. In each set, one cache way uses SECDED code and maintains dirty blocks while the other ways employ parity bit and keep clean blocks. To evaluate the set-associative cache, SIMPLESCALAR tool and CACTI analytical model are used. The experimental results show that as the feature size decreases and the associativity increases, the energy saving of the proposed cache increases. The experimental results express that for an 8-way setassociative cache in 32nm, about 7% area and...
Joint write policy and fault-tolerance mechanism selection for caches in DSM technologies: energy-reliability trade-off
, Article Proceedings of the 10th International Symposium on Quality Electronic Design, ISQED 2009, 16 March 2009 through 18 March 2009, San Jose, CA ; 2009 , Pages 839-844 ; 9781424429530 (ISBN) ; Ejlali, A ; Miremadi, G ; International Society for Quality Electronic Design, ISQED ; Sharif University of Technology
2009
Abstract
Write-through caches potentially have higher reliability than write-back caches. However, write-back caches are more energy efficient. This paper provides a comparison between the write-back and write-through policies based on the combination of reliability and energy consumption criteria. In the experiments, SIMPLESCALAR tool and CACTI model are used to evaluate the characteristics of the caches. The results show that a write-through cache with one parity bit per word is as reliable as a write-back cache with SEC-DED code per word. Furthermore, the results show that the energy saving of the write-through cache over the write-back cache increases if any of the following changes happens: i) a...
Multi objective planning for sustainable retrofit of educational buildings
, Article Journal of Building Engineering ; Volume 24 , 2019 ; 23527102 (ISSN) ; Aramoun, F ; Bararzadeh, M ; Avami, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The sustainable retrofit options may significantly improve the energy consumption and the environmental impacts of the existing buildings. This paper presents a multi objective optimization framework to reach the minimum economic costs and Global Warming Potential (GWP) impact of existing buildings. New energy-efficient technologies for the supply side of the energy system are considered which may minimize life cycle environmental impacts of buildings. Two educational buildings in the campus of Sharif University of Technology are studied. The results show that utilizing reciprocating engine and exhaust-fired absorption chiller reduce the GWP to 133 tons (17.79% of reduction) and 190 tones...
EiR: an energy-efficient routing algorithm for delay tolerant networks
, Article 9th International Symposium on Telecommunication, IST 2018, 17 December 2018 through 19 December 2018 ; 2019 , Pages 227-232 ; 9781538682746 (ISBN) ; Pakravan, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Delay Tolerant Networks (DTNs) are sparse and highly dynamic networks where intermittent connectivity is a common event. In these networks, nodes have time-limited connection opportunity to other moving nodes. Therefore, routing is a major challenge in these networks and researchers have tried to design efficient routing algorithms. Important performance metrics of desired routing algorithms are high delivery probability, low energy consumption and low end to end latency. In this paper, we propose an energy-efficient routing algorithm which is based upon the encounter probabilities of nodes. We use these encounter probabilities to derive a utility metric. Moreover, we utilize assumptions and...
A comprehensive analysis on the resilience of adiabatic logic families against transient faults
, Article Integration ; Volume 72 , May , 2020 , Pages 183-193 ; Safaei, B ; Ejlali, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
With the emergence of various battery operated technologies in different computing domains and the challenge of heating in such technologies, the issue of energy dissipation has become more critical than ever before. In such systems, energy constraints in one hand, and heat generation, on the other hand, necessitates the employment of energy efficient technologies in the fabrication of digital circuits. One possible solution for mitigating the energy dissipation in digital circuits is the use of adiabatic families in the process of designing computing devices. Adiabatic circuits are designed mainly based on the principles of thermodynamics and provide a paradigm shift in the design of...
A high energy-efficiency and low-area switching scheme for SAR ADCs
, Article Analog Integrated Circuits and Signal Processing ; 18 November , 2020 ; Sharifkhani, M ; Yazdani, S. B ; Sharif University of Technology
Springer
2020
Abstract
A high energy-efficiency and low-area switching method is proposed for the successive approximation register analog-to-digital converters. In the proposed scheme, the threshold voltage for comparison is derived from the charge sharing technique and using a voltage source connected to the bottom plates of the digital-to-analogue converter (DAC) capacitors. The switching method achieves an average DAC switching energy and DAC area reduction of 99.15% and 84.27%, respectively, with respect to the conventional method. The differential nonlinearity and integral nonlinearity of the proposed scheme are 0.1288 LSB and 0.1207 LSB, respectively. In addition, in the proposed method, the number of DAC...
A high energy-efficiency and low-area switching scheme for SAR ADCs
, Article Analog Integrated Circuits and Signal Processing ; Volume 106, Issue 2 , 2021 , Pages 449-457 ; 09251030 (ISSN) ; Sharifkhani, M ; Yazdani, S. B ; Sharif University of Technology
Springer
2021
Abstract
A high energy-efficiency and low-area switching method is proposed for the successive approximation register analog-to-digital converters. In the proposed scheme, the threshold voltage for comparison is derived from the charge sharing technique and using a voltage source connected to the bottom plates of the digital-to-analogue converter (DAC) capacitors. The switching method achieves an average DAC switching energy and DAC area reduction of 99.15% and 84.27%, respectively, with respect to the conventional method. The differential nonlinearity and integral nonlinearity of the proposed scheme are 0.1288 LSB and 0.1207 LSB, respectively. In addition, in the proposed method, the number of DAC...
Novel magnetic flowable electrode for redox flow batteries: A polysulfide/iodide case study
, Article Industrial and Engineering Chemistry Research ; Volume 60, Issue 2 , 2021 , Pages 824-841 ; 08885885 (ISSN) ; Molaei Dehkordi, A ; Gharibi, H ; Roberts, E. P. L ; Sharif University of Technology
American Chemical Society
2021
Abstract
A novel approach named a magnetic flowable electrode (MFE) is proposed for the first time to enable enhancement of redox flow batteries (RFBs) performance. This approach enables the formation of a high active surface area electrode from magnetic nanomaterials, without the need to fabricate a self-supporting three-dimensional electrode structure. To form a simple MFE, magnetic modified carbon nanotubes are dispersed in the electrolyte, and permanent magnets are embedded behind the current feeder to apply a magnetic field across the flow cell channels. With circulating electrolyte, magnetic carbon nanotubes are aggregated on the graphite bipolar plate to form a well-structured nanoscale...
ELITE: An elaborated cross-layer rpl objective function to achieve energy efficiency in internet-of-things devices
, Article IEEE Internet of Things Journal ; Volume 8, Issue 2 , 2021 , Pages 1169-1182 ; 23274662 (ISSN) ; Hosseini Monazzah, A. M ; Ejlali, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Energy consumption is a major challenge in IoT devices, which was aimed to be improved by employing energy-efficient objective functions (OFs) in the structure of the RPL routing protocol. Meanwhile, the majority of the existing OFs mainly perform the parent selection based on the gathered information from the routing layer. Nevertheless, based on our investigations, there exists a series of transmission operations in the medium access control (MAC) layer, which significantly affects the energy consumption in IoT devices. Therefore, in this article, we propose ELITE, an energy-efficient cross-layer OF, which introduces a novel routing metric, called strobe per packet ratio (SPR). SPR...
An approach to targeting cryptocurrency mining loads for energy efficiency enhancement
, Article IET Generation, Transmission and Distribution ; Volume 16, Issue 23 , 2022 , Pages 4775-4790 ; 17518687 (ISSN) ; Azimi Hosseini, K ; Hajipour, E ; Vakilian, M ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
In recent years, the mining of cryptocurrencies such as Bitcoin has attracted much global attention due to the simplicity and high profitability of this business, especially in countries with low electricity rates. The process of cryptocurrency mining using cryptocurrency mining devices requires a significant amount of computing power. This industry, which is increasingly growing in energy and carbon emissions, can cause environmental concerns. Common ways to reduce this amount of energy consumption are to prohibit mining and charge these loads at a higher electricity rate; however, these solution methods are not feasible and applicable in many countries. This paper presents an energy...
Using Learning Algorithms for Energy Efficient Routing in Wireless Sensor Network
, M.Sc. Thesis Sharif University of Technology ; Beigy, Hamid (Supervisor)
Abstract
Wireless Sensor Networks (WSNs) have attracted much attention in recent years for their unique characteristics and wide use in many different applications. WSNs are composed of many tiny sensor nodes that have limitations on energy level, bandwidth, processing power and memory. Therefore, reducing energy consumption and the increased network lifetime and scalability are the main routing challenges in sensor networks. Many algorithms were presented for routing in sensor networks; a class of theses algorithms is hierarchical algorithms based on clustering. Their main goals are to reduce energy consumption, distribution energy consumption in the whole network and increasing scalability. There...