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Structure-free real-time data aggregation in wireless sensor networks
, Article Computer Communications ; Volume 35, Issue 9 , 2012 , Pages 1132-1140 ; 01403664 (ISSN) ; Yeganeh, M. H ; Alinaghipour, N ; Movaghar, A ; Sharif University of Technology
2012
Abstract
Data aggregation is a very important method to conserve energy by eliminating the inherent redundancy of raw data in dense WSNs. Although structured approaches are particularly useful for data gathering applications, they incur high maintenance overhead in dynamic scenarios for event-based applications. 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 a structure-free Real-time data AGgregation protocol, RAG, using two mechanisms for temporal and spatial convergence of packets - Judiciously Waiting policy and Real-time Data-aware Anycasting policy. Using extensive...
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...
Opportunities for embedded software power reductions
, Article Canadian Conference on Electrical and Computer Engineering ; 2011 , Pages 000763-000766 ; 08407789 (ISSN) ; 9781424497898 (ISBN) ; Goudarzi, M ; Sharif University of Technology
2011
Abstract
While performance and power consumption of processors present a classic trade-off in designing embedded hardware, software can be optimized in favor of both performance and energy. We evaluate the impact of optimizations at different stages of designing embedded software. We show that algorithm choice and compiler optimizations aimed at improving performance can also reduce energy consumption of an embedded processor. We also propose energy-aware compilation guidelines which can further reduce energy consumption without performance penalties. Our experimental results show that up to 85% energy reduction and 89% performance improvement can be achieved by these techniques
An energy-aware methodology for mapping and scheduling of concurrent applications in MPSoC architectures
, Article 2011 19th Iranian Conference on Electrical Engineering, ICEE 2011, 17 May 2011 through 19 May 2011 ; May , 2011 , Page(s): 1 ; ISSN : 21647054 ; 9789644634284 (ISBN) ; Hessabi, S ; Vahdat, B. V ; Sharif University of Technology
2011
Abstract
Mapping and Scheduling are two central and critical steps in design flow of the Networks on Chips (NoCs). They deal with implementation of the applications on NoCs. In this paper a novel energy aware algorithm, called EAMS, for mapping and scheduling of concurrent applications to NoC platforms is developed. It is considered that, the NoC architecture consists of a set of heterogeneous IP cores. The introduced algorithm finds a mapping of the tasks of the application to available IP cores so that the overall energy consumption, meeting task deadlines, is minimized
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....
Offline replication and online energy management for hard real-time multicore systems
, Article CSI Symposium on Real-Time and Embedded Systems and Technologies, RTEST 2015, 7 October 2015 through 8 October 2015 ; October , 2015 , Page(s): 1 - 7 ; 9781467380478 (ISBN) ; Safari, S ; Ansari, M ; Salehi, M ; Ejlali, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
For real-time embedded systems, energy consumption and reliability are two major design concerns. We consider the problem of minimizing the energy consumption of a set of periodic real-time applications when running on a multi-core system while satisfying given reliability targets. Multi-core platforms provide a good capability for task replication in order to achieve given reliability targets. However, careless task replication may lead to significant energy overhead. Therefore, to provide a given reliability level with a reduced energy overhead, the level of replication and also the voltage and frequency assigned to each task should be determined cautiously. The goal of this paper is to...
EACHP: Energy Aware Clustering Hierarchy Protocol for Large Scale Wireless Sensor Networks
, Article Wireless Personal Communications ; Volume 85, Issue 3 , December , 2015 , Pages 765-789 ; 09296212 (ISSN) ; Movaghar, A ; Rahmani, A. M ; Sharif University of Technology
Springer New York LLC
2015
Abstract
Wireless sensor networks (WSNs) comprise a large number of small sensor nodes scattered across limited geographical areas. The nodes in such networks carry sources of limited and mainly unchangeable energy. Therefore, it is necessary that these networks operate under energy efficient protocols and structures. Energy efficient clustering algorithms have been developed to reduce the networks energy consumption and extend its lifetime. This paper presents an innovative cluster-based communication protocol for WSNs. In order to reduce communication overhead, the authors propose an Energy Aware Clustering Hierarchy Protocol that creates a multi-level hierarchical structure to adequately route and...
PDC: Prediction-based data-aware clustering in wireless sensor networks
, Article Journal of Parallel and Distributed Computing ; Volume 81-82 , July , 2015 , Pages 24-35 ; 07437315 (ISSN) ; Yousefi, H ; Basiri, J ; Hemmatyar, A. M. A ; Movaghar, A ; Sharif University of Technology
Academic Press Inc
2015
Abstract
Minimizing energy consumption is the most important concern in wireless sensor networks (WSNs). To achieve this, clustering and prediction methods can enjoy the inherent redundancy of raw data and reduce transmissions more effectively. In this paper, we focus on designing a prediction-based approach, named PDC, to mainly contribute in data-aware clustering. It exploits both spatial and temporal correlations to form highly stable clusters of nodes sensing similar values. Here, the sink node uses only the local prediction models of cluster heads to forecast all readings in the network without direct communication. To the best of our knowledge, PDC is a novel energy efficient approach which...
Energy-Aware Scheduling for Precedence-Constrained Parallel Virtual Machines in Virtualized Data Centers
, Article Journal of Grid Computing ; Volume 13, Issue 2 , 2015 , Pages 233-253 ; 15707873 (ISSN) ; Goudarzi, M ; Rajabi, A ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
Large scale Internet services are expected to only increase in complexity and popularity. Their energy consumption is also a major concern in data centers. Smart scheduling of their sub-services on data center Physical Machines (PM) can effectively improve their energy as well as performance. Since today servers are not energy-proportional yet, a major and traditionally neglected source of inefficiency in them is the utilization level of PMs. We present two scheduling algorithms for precedence-constrained parallel Virtual Machines (VM) in a virtualized data center where each VM represents a sub-service of the Internet-scale service. Our algorithms use virtualization technology to increase...
Leveraging dark silicon to optimize networks-on-chip topology
, Article Journal of Supercomputing ; Volume 71, Issue 9 , 2015 , Pages 3549-3566 ; 09208542 (ISSN) ; Sarbazi-Azad, H ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
This paper presents a reconfigurable network-on-chip (NoC) for many-core chip multiprocessors (CMPs) in the dark silicon era, where a considerable part of high-end chips cannot be powered up due to the power and bandwidth walls. Core specialization, which trades off the cheaper silicon area with energy-efficiency, is a promising solution to the dark silicon challenge. This approach integrates a selection of many diverse application-specific cores into a single many-core chip. Each application then activates those cores that best match its processing requirements. Since active cores may not always form a contiguous active region in the chip, such a partially active many-core CMP requires some...
Structure-aware online virtual machine consolidation for datacenter energy improvement in cloud computing
, Article Computers and Electrical Engineering ; Volume 42 , 2015 , Pages 74-89 ; 00457906 (ISSN) ; Pahlavan, A ; Goudarzi, M ; Sharif University of Technology
Abstract
The necessity and significance of improving the energy efficiency of cloud implementations have increased due to the rapid growth and proliferation of cloud computing services around the world. Virtual machines (VMs) comprise the backend of most, if not all, cloud computing services. Several VMs are often consolidated on a physical machine to efficiently utilize its resources. In this paper, we take into account the cooling and network structure of the datacenter host ing the physical machines when consolidating the VMs so that fewer racks and routers are employed, without compromising the service-level agreements; consequently, idle routing and cooling equipment can be turned off in order...
Optimising operational cost of a smart energy hub, the reinforcement learning approach
, Article International Journal of Parallel, Emergent and Distributed Systems ; Volume 30, Issue 4 , Oct , 2015 , Pages 325-341 ; 17445760 (ISSN) ; Sheikhi, A ; Ranjbar, A. M ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
The concept of smart grid (SG) has been introduced to improve the operation of the power systems. In modern structures of power systems, different reasons prompt researchers to suggest integrated analysis of multi-carrier energy systems. Considering synergy effects of the couplings between different energy carriers and utilising intelligent technologies for monitoring and controlling of energy flow may change energy system management in the future. In this paper, we propose a new solution which is entitled smart energy hub (SEH) that models a multi-carrier energy system in a SG. SEH solutions allow homeowners to manage their energy consumption to reduce their electricity and gas bill. We...
In-scratchpad memory replication: Protecting scratchpad memories in multicore embedded systems against soft errors
, Article ACM Transactions on Design Automation of Electronic Systems ; Volume 20, Issue 4 , 2015 ; 10844309 (ISSN) ; Farbeh, H ; Miremadi, S. G ; Sharif University of Technology
Association for Computing Machinery
2015
Abstract
Scratchpad memories (SPMs) are widely employed inmulticore embedded processors. Reliability is one of the major constraints in the embedded processor design, which is threatened with the increasing susceptibility of memory cells to multiple-bit upsets (MBUs) due to continuous technology down-scaling. This article proposes a low-cost and efficient data replication mechanism, called In-Scratchpad Memory Replication (ISMR), to correct MBUs in SPMs of multicore embedded processors. The main feature of ISMR is a smart controller, called Replication Management Unit (RMU), which is responsible for dynamically analyzing the activity of the SPM blocks at runtime and efficiently replicating the...
Simulation of thermal profile in a single pellet during drying process with CFD method
, Article Proceedings of the 24th International Mining Congress of Turkey, IMCET 2015, 14 April 2015 through 17 April 2015 ; 2015 , Pages 797-803 ; 9786050107050 (ISBN) ; Namehi, A ; Vali, H ; Shahrokhshahi, H. R ; Soltani, H ; Alamdari, E. K ; Cheraghi, A ; Karadeniz, M ; Gulsun Kilic, M ; Torun Bilgic, E ; Basarir, H ; Onel, O ; Sharif University of Technology
TMMOB Maden Muhendisleri Odasi
2015
Abstract
Green iron oxide pellets are indurated with thermal treatment in pelletizing plant to achieve sufficient mechanical properties and to be used in iron-steel industry. In the first stage, the pellets are dried with hot air coming from the firing unit. High heat transfer makes the evaporation rate exceeding the outgoing steam rate from the pellets and as a result, increasing the inner pressure of the pellets and fragment. On the other hand, low heat transfer causes low production rate. Using the related equations and considering the pellets' moisture and porosity and applying the pellets' condition on parameters such as specific heat capacity and heat conductivity, an acceptable standard is...
The addition of data aggregation to non cluster based SPEED routing algorithm while keeping the functionality of available techniques inorder to increase QoS
, Article ; Volume 2 , April , 2010 , Pages V2696-V2700 ; ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings, 16 April 2010 through 18 April 2010 ; 9781424463503 (ISBN) ; Roustaei, R ; Movaghar, A ; Sharif University of Technology
2010
Abstract
Data aggregation is a technique that is used to decrease extra and repetitive data in cluster based routing protocols. As we know SPEED routing algorithm is based on service quality and dose not perform data aggregation. In this article, we try to add an data aggregation technique to the available techniques without interfering with the functions of previous ones. The idea involves virtual configuration of sensors and specification of an individual ID to the created data by the sensors in each region, then data aggregation in relay node is done by this ID, resulting in less energy consumption, lower traffic and repeated data, an increase in network lifetime and better quality of service
Timetable optimization for maximum usage of regenerative energy of braking in electrical railway systems
, Article SPEEDAM 2010 - International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 14 June 2010 through 16 June 2010 ; June , 2010 , Pages 1218-1221 ; 9781424449873 (ISBN) ; Fekri Moghadam, M ; Mokhtari, H ; Sharif University of Technology
2010
Abstract
Research projects in urban transportation systems require proper simulation softwares. Such softwares are the basic requirements of any kind of study in electrical transportation systems. Due to high energy consumption of these systems, studies for its optimization are challenging and necessary. In this paper an optimized timetable of trains? movement is proposed in order to completely utilize the regenerative energy of trains? braking in stations. A sample subway system is simulated and Genetic algorithm is used as an optimization method. The effect of headway and reserve times on the amount of energy consumption is studied and an optimized reserve time set is found for the sample system....
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) ; Sarbazi Azad, H ; Sharif University of Technology
2010
Abstract
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...
Optimization of cleaning procedure for polyethersulfone (PES) membrane by a statistically designed approach
, Article Recent Patents on Chemical Engineering ; Volume 6, Issue 2 , August , 2013 , Pages 107-115 ; 18744788 (ISSN) ; Sargolzaei, J ; Shayegan, J ; Bahadori, T ; Sharif University of Technology
Abstract
Physical separation methods, especially membrane technology, can be a good substitute for biological wastewater treatment, due to its simple constructions and operations. There are many papers and patents in this field. Membranes need to be cleaned periodically to be able to operate economically, and need to be replaced after a while. Several factors can influence the membrane cleaning procedure, including pressure of backwash, acid and base concentration, duration of forward washing, and duration of acid-base backwashing. In this study the effect of these parameters was investigated to find an optimum condition which could result in a good polyethersulphone (PES) membrane cleaning with less...
On joint energy and information transfer in relay networks with an imperfect power amplifier
, Article IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, 4 September 2016 through 8 September 2016 ; 2016 ; 9781509032549 (ISBN) ; Makki, B ; Nasiri Kenari, M ; Svensson, T ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This paper investigates the outage probability and the throughput of relay networks with joint information and energy transfer where the relay harvests energy from transmitted radio-frequency (RF) signal of the source. Considering different power consumption models, we derive the outage probability of the systems for both adaptive and non-adaptive power allocations at the relay. With a total energy consumption constraint at the source, we provide closed-form expressions for the optimal time sharing and power allocation between the source energy and information transfer signals. The analytical and simulation results demonstrate the efficiency of joint energy and information transfer systems...
A technical and economic assessment of variants for CO2 separation from synthesis gas
, Article Energy Sources, Part B: Economics, Planning and Policy ; Volume 11, Issue 12 , 2016 , Pages 1097-1102 ; 15567249 (ISSN) ; Nouri Khorasani, A ; Baghalha, M ; Pazos Costa, A ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
An analysis of carbon dioxide (CO2) removal process from synthesis gas has been carried out in this work. CO2 removals by physical and chemical solvents are the most often used. The most important factors that affect cost and performance of a CO2 recovery unit are the number of flash drum separation units, and the pressure drop pattern among them. Different variations of this process were simulated using Hysys software, and the capital and operational expenditures for these plants were estimated. The focus was to reach an optimum process to minimize the total unit cost of separated CO2. The results indicate that for a fixed number of separation units, the case with uniform pressure drop...