Search for: energy-optimization
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    ISP: Using idle SMs in hardware-based prefetching

    , Article Proceedings - 17th CSI International Symposium on Computer Architecture and Digital Systems, CADS 2013 ; October , 2013 , Pages 3-8 ; 9781479905621 (ISBN) Falahati, H ; Abdi, M ; Baniasadi, A ; Hessabi, S ; Computer Society of Iran; IPM ; Sharif University of Technology
    IEEE Computer Society  2013
    The Graphics Processing Unit (GPU) is the most promising candidate platform for faster rate of improvement 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 architecture challenges. In this paper, we focus on improving performance by better hiding long waiting time to transfer data from the slow global memory. Thereupon study an effective light-overhead prefetching mechanism, which utilizes idle processing elements. Our results show that we can potentially improve... 

    An innovative design and cost optimization of a trigeneration (combined cooling, heating and power) system

    , Article International Journal of Environmental Research ; Volume 8, Issue 4 , 2014 , Pages 971-978 ; ISSN: 17356865 Abbaspour, M ; Saraei, A. R ; Sharif University of Technology
    Load management and cost optimization are among the important factors in trigeneration systems and combined cooling, heating and power (CCHP) systems. In this study, an innovative CCHP system uses a gas turbine as the prime mover and has a heat recovery steam generator (HRSG) in addition to an auxiliary boiler, electric and absorption chillers. The system is tied with the bulk electric grid; to export and sell excess power or import power when necessary. This study analyzes load management and cost optimization of CCHP systems. A heuristic strategy to optimize the total energy cost is then presented. The optimal size of CCHP is determined from the study results. This paper proposes a model... 

    Development of a Demand Side Management Model for an Educational Building

    , M.Sc. Thesis Sharif University of Technology Haddadi, Amir Hossein (Author) ;
    Building sector is one of the largest energy conumers by being responsible for 40% of final energy consumption worldwide. In Iran, buildings consume around 32.5% of natural gas and 51.6% of generated electricity which is a significant portion of national energy system. Energy management consists of solutions which minimise energy consumption of a building while maintaining comfort conditions. The present research studies energy management solutions under a short–term model for an educational building using Energy-Plus software. The Department of Energy Engineering of Sharif University of Technology is selected as the case study and the optimal solutions has been achieved for this building.... 

    Energy Efficient Routing and Resource Allocation in Optical Networks

    , M.Sc. Thesis Sharif University of Technology Fallahpour, Ahmad (Author) ; Salehi,Javad (Supervisor)
    As the Internet traffic grows, the energy efficiency gains more attention as a design factor for the planning and operation of telecommunication networks. Therefore, researchers begin to devise solutions for energy conservation in many scientific disciplines. In this thesis, we focus on the study of energy efficiency in optical transport networks, specially, the newly proposed Spectrum sLICed Elastic optical path (SLICE) networks architecture. First of all, we will introduce energy consuming elements in SLICE networks and their power consumption model. Next, we present a dynamic energy efficient routing and spectrum assignment algorithm (EE-RSA) with regenerator placement (RP) capability for... 

    Reducing Energy Consumption Considering Stochastic Distribution of Network Traffic

    , M.Sc. Thesis Sharif University of Technology Malekloo, Ashkan (Author) ; Goudarzi, Maziar (Supervisor)
    In the past few years, because of the high energy price in data centers, optimizing energy consumption has become of real importance. The disproportionate energy consumption of network devices to their utilization has led them to become one of the biggest consumers of energy inside data centers. On the other hand, the stochastic nature of network traffic among virtual machines has made the assumption of known or fixed communication volume superficial. In this research we considered a stochastic distribution of network traffic and communication volume among virtual machines trying to change the communication inside data center to communication inside hosts. Initially, we start by evaluating... 

    Investigation of Atrium Shape Influence on Natural Ventilation Performance & CFD Model

    , M.Sc. Thesis Sharif University of Technology Shafiee, Ali (Author) ; Moosavi, Ali (Supervisor)
    In modern era, standpoints about atrium design have been revolutionized. In modern architecture, atrium not only designed for illuminating purposes but also designed by natural ventilation and passive cooling policies. Numerous parameters are making role in thermal efficiency of Atrium. A couple of these parameters are Atrium shape and openings area. In high rise atria the lower level rooms enjoy the advantage of buoyancy-driven ventilation while the upper level rooms suffer from its lack or weak presence. One strategy to solve this problem is designing building with various opening area in different heights but manipulating the opening size is restricted by some facts. Excessive Opening’s... 

    Experimental Investigation of Drag Reduction Induced by Superhydrophobic Surface

    , M.Sc. Thesis Sharif University of Technology Taghvaei, Ehsan (Author) ; Moosavi, Ali (Supervisor) ; Nouri Borujerdi, Ali ($item.subfieldsMap.e)
    The increasing demand of energy and energy consumption, urged researchers of different fields of science to investigate different aspects of energy efficiency methods. One way of optimization of energy consumption is to reduce drag force in moving objects in fluids. Changing the geometry of objects, bubble injection, air suction and blowing on surface, using nano fluid and superhydrophobic surface are just a number of drag reduction methods. Among the mentioned methods, using superhydrophobic surface due to its simplicity, low cost and no need to change in geometry of vehicles attracted attentions of researchers of all over the world. These surfaces with micro/nano roughness combined with... 

    An energy method for analysing deep drawing process by simulated annealing optimization algorithm

    , Article JSME International Journal, Series C: Mechanical Systems, Machine Elements and Manufacturing ; Volume 48, Issue 1 , 2005 , Pages 95-102 ; 13447653 (ISSN) Assempour, A ; Gandomkar, M ; Sharif University of Technology
    A systematic approach of the energy method has been used for analyzing of deep drawing process. The so called simulated annealing algorithm has been used for energy optimization. In this method, the whole deforming region has been divided into five zones. Then the geometry has been expressed by sweeping the section curves defined on the boundary of each zone. The velocity fields have been expressed in a similar manner by sweeping the boundary velocity functions. In every step, the solution has been found through optimization of the total energy dissipation with respect to some parameters assumed in kinematically admissible velocity field defined over each zone. The energy dissipated in the... 

    Energy Optimization of an Arm with Seven Degrees of Freedom Using Imperialistic Competitive Algorithm (ICA) and Designing an Artificial Neural Network

    , M.Sc. Thesis Sharif University of Technology Abedini, Amin (Author) ; Ahmadian, M.T (Supervisor) ; Asghari, M (Supervisor)
    In recent years, great attention has been devoted to the design of artificial arms. The most crucial problem in such a design is the trajectory of movement. In this paper, a seven degree of freedom arm is modeled and simulated. Also, the optimization method named “Imperialistic Competitive Algorithm” has been modified and better performance of the new version is presented. Energy optimization is performed based on trajectory of the arm with angular velocity, angular acceleration and joint angles using modified imperialistic competitive algorithm (ICA). Considering ICA as a fast optimization algorithm, it would be reasonable to use this algorithm for robotic purposes for online answering. The... 

    Energy Optimization in Roadside Unit in Vehicular Ad-hoc Networks

    , M.Sc. Thesis Sharif University of Technology Rashidi, Zahra (Author) ; Afshin Hemmatyar, Ali Mohammad (Supervisor)
    Optimization of energy consumption is generally important in mobile networks and in particular in automotive networks. One of the challenges of installing roadside units in automotive case networks is to provide energy to the equipment assigned to these units. In some cases, power is easily available, but in many places, the cost of energy is very high and does not have economic justification. Therefore, optimization of energy consumption in roadside unit is of great importance. Typically, vehicles limitations in terms of energy consumption for communications are far lower than that of a roadside unit. In this dissertation, part of roadside communication to vehicles is shifted to the... 

    An Optimization Model for Water and Energy Network based on Process Simulation for Production of ETBE from Biomass

    , M.Sc. Thesis Sharif University of Technology Modiri, Mahshad (Author) ; Avami, Akram (Supervisor)
    Fossil fuel usage caused global warming and other environmental problems. Recently, biofuels are considered as an important alternative. However, the efficient usage of water and energy in their production may accelerate their diffusion. ETBE is a kind of oxidizing fuel additive that can be biologically produced from the ethanol reaction. High water and energy consumption in the production and separation process is still a challenge. In this work, the ETBE production from lignocellulosic feed are considered. Then, the effect of different parameters are investigated by performing sensitivity analysis. In the next step, the optimal pathway of water and energy use in the production of ETBE are... 

    The Application of Hybrid Ventilation to Meet Large Office Building Cooling Demand

    , M.Sc. Thesis Sharif University of Technology Talebjedi, Behnam (Author) ; Rajabi Ghahnavieh, Abbas (Supervisor)
    In the past due to the lack of mechanical systems for air conditioning in the interior spaces, the buildings were designed to be able to maximize the use of natural forces such as solar and wind power. Natural ventilation is an old method of using natural forces. For example, wind tower is one of the traditional elements for using natural ventilation in the warm seasons for benefiting from wind and sun energy. In our country, Iran, in cities like Yazd, which are located in a warm and dry climate, the use of wind towers is very common and our predecessors were pioneer in this field. With the passage of time and the development of mechanical air conditioning systems, the use of natural... 

    Design and Implementation of Software-Managed Energy Optimization Techniques for a Multi-Core Embedded Processor

    , M.Sc. Thesis Sharif University of Technology Karimi Fatemi, Masoud (Author) ; Ejlali, Alireza (Supervisor)
    Nowadays, due to the need of high performance systems, embedded systems have been redirected to multicore architectures. As energy consumption is one of the most important issues in embedded systems, careful considerations must be taken during the design of embedded systems to achieve low energy consumption. In this thesis, we propose the use of hybrid scratchpad memories to achieve low energy consumption. The hybrid memory uses both SRAM and STT-RAM memory. While STT-RAM has very low static energy consumption it suffers from high latency and energy consumption during write activities. In order to tackle this problem, we have devised a genetic algorithm that exploits architecture information... 

    Regionalized Lifetime-aware Virtual Machine Consolidation Algorithm for Cloud Datacenters

    , M.Sc. Thesis Sharif University of Technology Varasteh Hajipour, Amir (Author) ; Goudarzi, Maziar (Supervisor)
    In the past few years, data centers energy consumption and their maintenance costs have become an important issue in technology world. Server consolidation using virtualization and VM live migration allows cloud data centers to improve resource utilization and hence energy efficiency. In order to save energy, consolidation techniques try to turn off the idle servers, while because of workload fluctuations, these offline servers should be turned on to support the increased resource demands. These repeated on-off cycles could affect the hardware reliability and wear-and-tear of servers and increase the maintenance and replacement costs. On the other hand, over-aggressive strategies would... 

    Optimisation of Energy Flow Model for an Educational Building

    , M.Sc. Thesis Sharif University of Technology Ghomian, Atefe (Author) ; Saboohi, Yadollah (Supervisor) ; Roshandel, Ramin (Supervisor)
    Increase in energy consumed by buildings, which constitute about 40% of the global final energy consumption and their respective contribution to CO2 emmission has led the building owners and users toward using on–site energy production systems and especially clean energy sources. The present research aims to find the optimal solution to the building energy supply problem under current and other possible circumstances. Energy Engineering Department of Sharif University of Technology has been selected in representation of educational buildings in Iran for case study. ESM software which is based on the MESSAGE model has been used as the modeling tool. Results state that under the current... 

    Development of Carbon Management Hierarchy Method Based on Process Integration Techniques

    , M.Sc. Thesis Sharif University of Technology Fooladi, Fatemeh (Author) ; Avami, Akram (Supervisor)
    Continuous increase of energy demand, scarcity of resources, as well as environmental limitations have led to the need to reduce carbon emissions. In this research, an MINLP model based on the mathematical optimization formulation is proposed to reach this issue in a large cogeneration unit. Advantage of the hierarchical approach for carbon management are avoiding individual carbon reduction policies, and embedding emission control techniques in a hierarchical mathematical model that helps us to select the most appropriate policies and prioritize each other. In the carbon management hierarchy, the optimization of the base cycle is done at the first stage. Then, the use of renewable energies... 

    Improved optimal control technique for control of parallel three- phase inverters

    , Article 2009 International Conference on Electric Power and Energy Conversion Systems, EPECS 2009, Sharjah, 10 November 2009 through 12 November 2009 ; 2009 ; 9789948427155 (ISBN) pouya, H. R. N ; Mokhtari, H ; Sharif University of Technology
    This paper proposes a high performance voltage tracking and current sharing among parallel connected inverters by applying optimal control and minimizing the cost function. The control system forces the voltage of load to track the voltage reference, and the current of all inverters becomes equal. Therefore, both current sharing and voltage tracking are obtained. In addition, the smallest input energy and simplicity in control circuit are the other advantages of the suggested method. To show the performance of the proposed control scheme, the simulations with two-modular practical systems are performed and the results are provided. The results indicate that the control objectives are... 

    Effects of flexible ramping product on improving power system real-time operation

    , Article 2017 25th Iranian Conference on Electrical Engineering, ICEE 2017, 2 May 2017 through 4 May 2017 ; 2017 , Pages 1187-1192 ; 9781509059638 (ISBN) Khoshjahan, M ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
    Integration of renewable energies in generation sector of power systems has caused many new issues for planners and decision makers. Therefore, new concepts such as flexibility are introduced to properly cover these problems. In this paper, a recently announced short-term flexibility product, namely, 'Flexible ramping product' (FRP) in power markets is put under investigation from different aspects. FRP is the capacity reserved to meet next upcoming five-minute net load (load minus intermittent supply) uncertainty. Therefore, at first, the mathematical model of real-time dispatch (RTD) problem in presence of the FRP is formulated. Modeling this problem as a linear programming (LP)... 

    Energy consumption in pervaporation, conventional and hybrid processes to separate toluene and i-octane

    , Article Chemical Engineering and Processing - Process Intensification ; Volume 128 , June , 2018 , Pages 46-52 ; 02552701 (ISSN) Khazaei, A ; Mohebbi, V ; Mosayyebi Behbahani, R ; Ramazani Saadat Abadi, A ; Sharif University of Technology
    Elsevier B.V  2018
    Chemical industries need to employ new process designs due to environmental policies and energy optimization because of the global energy challenge. Pervaporation has been introduced as a promising alternative for conventional processes such as distillation, known as energy intensive process, in chemical plants. In this work, the energy consumption of different processes for separation of toluene and i-octane (representatives of aromatics and aliphatic mixtures) has been evaluated, based on our previous laboratory pervaporation experiments using Polyvinyl alcohol/Graphene oxide mixed matrix membranes. Accordingly, hybrid distillation-pervaporation and cascade pervaporation systems have been... 

    Optimal scheduling of renewable-based energy hubs considering time-of-use pricing scheme

    , Article 2017 IEEE Smart Grid Conference, SGC 2017, 20 December 2017 through 21 December 2017 ; Volume 2018-January , March , 2018 , Pages 1-6 ; 9781538642795 (ISBN) Pasban Gajan, A ; Moeini Aghtaie, M ; Parvini, Z ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    To more clearly show the abilities of multi-energy carrier systems in managing different energy demands, this paper investigates optimal scheduling of an energy hub in presence of price-based demand response (DR) programs. In this regard, the mathematical model of different energy converters and storage units including combined heat and power (CHP), electrical storage, heat storage and ice storage are extracted. Then, time-of-use (TOU) electrical energy price is set in such a way to reach lower demand in peak hours. Extracting the optimization model of energy scheduling for an energy hub in presence of TOU DR program, the proposed algorithm is implemented on a typical energy hub and the...