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    Project Scheduling Subject to Non-Renewable Perishable Resources

    , M.Sc. Thesis Sharif University of Technology Najafi Farashah, Mohammad Hadi (Author) ; Shadrokh, Shahram (Supervisor)
    Abstract
    In this research a mathematical formulation is presented for project scheduling problem subject to non-renewable perishable resources where the objective is minimize the cost of ordering and maintenance of resources. We use the framework of a resource constrained project scheduling problem (RCPSP) with finish-start precedence relations between activities and resources will be perished after a determined duration and must be procured. Resource procurement have ordering and purchasing costs and excess resources must be stored and have maintenance cost. There is a unique way to perform the activities and preemption is not allowed.
    This work employs Genetics Algorithms to solve the problem... 

    Predicting the environmental economic dispatch problem for reducing waste nonrenewable materials via an innovative constraint multi-objective Chimp Optimization Algorithm

    , Article Journal of Cleaner Production ; Volume 365 , 2022 ; 09596526 (ISSN) Zhu, L ; Ren, H ; Habibi, M ; Mohammed, K. J ; Khadimallah, M. A ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The usage of conventional fossil fuels has aided fast economic growth while also having negative consequences, such as increased global warming and the destruction of the ecosystem. This paper proposes a novel swarm-based metaheuristic method called Chimp Optimization Algorithm (ChOA) to tackle the environmental, economic dispatch issue and reducing the waste nonrenewable materials. In this regard, two objective functions named fuel cost function and emission cost function are proposed. Unique constrained handling also solves the challenge of multi-objective optimization. Standard IEEE 30 bus with six generators and a 10-unit system are used to demonstrate the usefulness of ChOA. The result... 

    Operational strategy optimization of a hybrid green power system based on fuzzy logic controller with considering for optimal sizing and analysis of different priorities for energy storage

    , Article Sustainable Energy, Grids and Networks ; Volume 32 , 2022 ; 23524677 (ISSN) Zahedi, R ; Moeini Aghtaie, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Renewable energy (RE) as a new player in the generation sector of power systems imposes new challenges to the system operators. The intermittent nature of REs for systems where are autonomous calls for new operational and planning strategies to reach more efficient power management. An autonomous hybrid green power system (HGPS) should be able to meet the load while keeping the cost of the HGPS as low as possible. Many studies have presented different un-optimal and optimal operational strategies, a few of which were optimally sized. In this regard, this paper develops a new thorough framework for designing and optimizing an autonomous HGPS. To reach this goal, the proposed model (a)... 

    Electrolytic capacitor-less AC-DC LED driver with constant output current and PFC

    , Article 6th Annual International Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2015, 3 February 2015 through 4 February 2015 ; 2015 , Pages 107-112 ; 9781479976539 (ISBN) Valipour, H ; Rezazadeh, G ; Zolghadri, M. R ; Noroozi, N ; Sharif University of Technology
    Abstract
    Recent developments in improving lighting efficiency and cost reduction of LED's have caused them to be a suitable alternative for the current lighting systems. In this paper a novel off-line structure is proposed to drive LED's. The proposed circuit has a high power factor and high efficiency and a long lifetime. To increase the life time of the converter, the proposed circuit doesn't use any electrolytic capacitors in the power stage. The proposed circuit consists of a transition mode (TM) Flyback converter in order to have power factor correction (PFC). A Buck converter is added to the third winding of the Flyback transformer in order to create two paths for the electrical power. DC power... 

    Flicker-free electrolytic capacitor-less universal input offline LED driver with PFC

    , Article IEEE Transactions on Power Electronics ; Volume 31, Issue 9 , 2016 , Pages 6553-6561 ; 08858993 (ISSN) Valipour, H ; Rezazadeh, G ; Zolghadri, M. R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    Recent developments in improving lighting efficiency and cost reduction of LEDs have made them suitable alternatives to the current lighting systems. In this paper, a novel offline structure is proposed to drive LEDs. The proposed circuit has a high-input power factor, high efficiency, a long lifetime, and it produces no flicker. To increase the lifetime of the converter, the proposed circuit does not include any electrolytic capacitors in the power stage. The proposed circuit consists of a transition mode flyback converter in order to improve power factor. Additionally, a buck converter is added to the third winding of the flyback transformer in order to create two parallel paths for the... 

    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) Tavakoli, A ; 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... 

    Toward a business model for software product line architecture

    , Article 8th ACIS International Conference on Software Engineering Research, Management and Applications, SERA 2010, 24 May 2010 through 26 May 2010, Montreal, QC ; 2010 , Pages 50-56 ; 9780769540757 (ISBN) Tanhaei, M ; Moaven, S ; Habibi, J ; Ahmadi, H ; Sharif University of Technology
    2010
    Abstract
    Nowadays, software product line is an approach to reduce costs of software development, decrease time to market, and increase capabilities of reuse in designing and exploiting software development processes. Moreover, other quality attributes of the project domain should be considered to enhance quality of the product. Meanwhile, taking advantage of software product line makes developers capable of estimating development costs and time to market in a more realistic way. However, old approaches to estimate cost of development and foresee time to market are not suitable enough for software product line. In this paper, some important business parameters and a way to calculate cost and time to... 

    Toward an architecture-based method for selecting composer components to make software product line

    , Article ITNG2010 - 7th International Conference on Information Technology: New Generations, 12 April 2010 through 14 April 2010 ; April , 2010 , Pages 1233-1236 ; 9780769539843 (ISBN) Tanhaei, M ; Moaven, S ; Habibi, J ; Sharif University of Technology
    2010
    Abstract
    Nowadays, product line, as an important topic in software development domain, has been paid attention by software engineering practitioners. Finding suitable components to construct an efficient and comprehensive product line with low costs is one of the critical problems in this domain which demands to be satisfied. In this paper a method is presented which can manage and control complexities of component selection problem, an NP problem, and result in creation of declared product line. By making use of this method, a product line will be constructed with suitably-adopted components to cover up requirements based on architecture; that's why software product line development process will... 

    Cost-aware reactive monitoring in resource-constrained wireless sensor networks

    , Article 2009 IEEE Wireless Communications and Networking Conference, WCNC 2009, Budapest, 5 April 2009 through 8 April 2009 ; 2009 ; 15253511 (ISSN); 9781424429486 (ISBN) Talebi, M ; Khonsari, A ; Jabarvand, R ; Sharif University of Technology
    2009
    Abstract
    Motivated by applications of sensor networks, there has been growing interest in monitoring large scale distributed systems. In these applications, we usually wish to monitor a global system condition defined as a function of local network elements parameters. In this paper, we study Reactive Monitoring in sensor networks, which has the benefit of operating in a decentralized manner. Our primary concern in adopting such a monitoring paradigm is reducing the communication cost which is the dominant factor of energy drain in wireless sensor networks. In this study, we address the reactive aggregate monitoring problem by casting the underlying threshold assignment as an optimization problem.... 

    Landmark extraction from echocardiography sequence based on corner detection algorithms using product moment coefficient matcher

    , Article 2009 International Conference on Signal Processing Systems, ICSPS 2009, Singapore, 15 May 2009 through 17 May 2009 ; 2009 , Pages 91-97 ; 9780769536545 (ISBN) Siyah Mansoory, M ; Behnam, H ; Fatemi Zadeh, E ; Sharif University of Technology
    2009
    Abstract
    Landmark extraction is used as the first step of many vision tasks such as tracking, image registration, localization, image matching and recognition. Furthermore, landmarks are used to reduce the data flow and consequently the computational costs. In this paper we extracted landmarks from echocardiography sequence, our algorithm is based on corner extraction, and then we evaluate our algorithm with applying some test. For this purpose, we evaluated the detectors according to their repeatability, stability and landmark localization under changes in noise. © 2009 IEEE  

    Landmark extraction from echocardiography sequence based on corner detection algorithms using gradient vector matcher

    , Article 2009 International Association of Computer Science and Information Technology - Spring Conference, IACSIT-SC 2009, Singapore, 17 April 2009 through 20 April 2009 ; 2009 , Pages 510-516 ; 9780769536538 (ISBN) Siyah Mansoory, M ; Behnam, H ; Fatemi Zadeh, E ; Sharif University of Technology
    2009
    Abstract
    Landmark extraction is used as the first step of many vision tasks such as tracking, image registration, localization, image matching and recognition. Furthermore, landmarks are used to reduce the data flow and consequently the computational costs. In this paper we extracted landmarks from echocardiography sequence, our algorithm is based on corner extraction, and then we evaluate our algorithm with applying some test. For this purpose, we evaluated the detectors according to their repeatability, stability and landmark localization under changes in noise. © 2009 IEEE  

    Recent progress in inorganic and composite coatings with bactericidal capability for orthopaedic applications

    , Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 7, Issue 1 , Feb , 2011 , Pages 22-39 ; 15499634 (ISSN) Simchi, A ; Tamjid, E ; Pishbin, F ; Boccaccini, A. R ; Sharif University of Technology
    Abstract
    This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some... 

    Optimal distribution network automation considering earth fault events

    , Article IEEE Transactions on Smart Grid ; Vol. 6, issue. 2 , 2015 , p. 1010-1018 ; ISSN: 19493053 Siirto, O. K ; Safdarian, A ; Lehtonen, M ; Fotuhi-Firuzabad, M ; Sharif University of Technology
    Abstract
    In the past decade, distribution network operators have been broadly engrossed toward automated distribution networks. The operators acknowledge network automation as an efficient investment toward a better service reliability. This paper aims to provide a new long-term cost/benefit analysis for an optimal level of distribution network automation. In the analysis, reduction in customer outage cost is considered as the benefit of implementing automation systems with capital investment, and annual operation and maintenance costs. In the Finnish regulation model, there is a special incentive based on customer outage cost reduction. As the main contribution of this paper, the impact of earth... 

    Optimal distribution network automation considering earth fault events

    , Article IEEE Transactions on Smart Grid ; Volume 6, Issue 2 , 2015 , Pages 1010-1018 ; 19493053 (ISSN) Siirto, O. K ; Safdarian, A ; Lehtonen, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Abstract
    In the past decade, distribution network operators have been broadly engrossed toward automated distribution networks. The operators acknowledge network automation as an efficient investment toward a better service reliability. This paper aims to provide a new long-term cost/benefit analysis for an optimal level of distribution network automation. In the analysis, reduction in customer outage cost is considered as the benefit of implementing automation systems with capital investment, and annual operation and maintenance costs. In the Finnish regulation model, there is a special incentive based on customer outage cost reduction. As the main contribution of this paper, the impact of earth... 

    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) Shirmohammadi, Z ; 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... 

    Reducing motion estimation time with skin detection

    , Article 2009 IEEE International Workshop on Imaging Systems and Techniques, IST 2009, Hong Kong, 11 May 2009 through 12 May 2009 ; 2009 , Pages 71-75 ; 9781424434831 (ISBN) Shirali Shahreza, M. H ; Shirali Shahreza, S ; IEEE Instrumentation and Measurement Society ; Sharif University of Technology
    2009
    Abstract
    Motion estimation (ME) is one of the key parts of video compression algorithms. But, motion estimation and computation of motion vectors (MVs) are very time con-suming. In this paper, we propose a method for reducing the cost of motion estimation process. During this process, a series of candidate blocks should be searched to find the best motion vectors. In our method, we compare the skin parts of two blocks before comparing all pixel pairs of the two blocks. Having a preprocessing phase, the skin part comparison is performed quickly. This method provides a parameter that can be used to create a balance between the processing time and the motion estimation accuracy. © 2009 IEEE  

    Extended opportunity cost model to find near equilibrium electricity prices under non-convexities

    , Article Applied Energy ; Volume 240 , 2019 , Pages 251-264 ; 03062619 (ISSN) Shavandi, H ; Pirnia, M ; Fuller, J. D ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    This paper finds near equilibrium prices for electricity markets with non-convexities due to binary variables, in order to reduce the market participants’ opportunity costs, such as generators’ unrecovered costs. The opportunity cost is defined as the difference between the profit when the instructions of the market operator are followed and when the market participants can freely make their own decisions based on the market prices. We use the minimum complementarity approximation to the minimum total opportunity cost model, from previous research, with tests on a much more realistic unit commitment model than in previous research, including features such as reserve requirements, ramping... 

    The impact of demand response programs on UPFC placement

    , Article Turkish Journal of Electrical Engineering and Computer Sciences ; Volume 27, Issue 6 , 2019 , Pages 4624-4639 ; 13000632 (ISSN) Sharifi Nasab Anari, A ; Ehsan, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
    Turkiye Klinikleri  2019
    Abstract
    Demand response (DR) and flexible AC transmission system (FACTS) devices can be effectively used for congestion management in power transmission systems. However, demand response program (DRP) implementation can itself affect the optimum location of FACTS devices, which is one of the main issues in power system planning. This paper investigates the impact of DRPs on unified power flow controller (UPFC) placement. The harmony search algorithm is employed to determine the optimum locations and parameter setting of UPFC in a long-term framework. The optimization problem is solved with different objectives including generation and congestion cost reduction, as well as loss reduction. In this... 

    Development of a shell superelement for large deformation and free vibration analysis of composite spherical shells

    , Article Engineering with Computers ; 2020 Shamloofard, M ; Hosseinzadeh, A ; Movahhedy, M. R ; Sharif University of Technology
    Springer  2020
    Abstract
    Finite element analysis of huge and/or complicated structures often requires long times and large computational expenses. Superelements are huge elements that exploit the deformation theory of a specific problem to provide the capability of discretizing the problem with minimum number of elements. They are employed to reduce the computational cost while retaining the accuracy of results in FEM analysis of engineering problems. In this research, a new shell superelement is presented to study linear/nonlinear static and free vibration analysis of spherical structures with partial or full spherical geometries that exist in many industrial applications. Furthermore, this study investigates the... 

    Development of a shell superelement for large deformation and free vibration analysis of composite spherical shells

    , Article Engineering with Computers ; Volume 37, Issue 4 , 2021 , Pages 3551-3567 ; 01770667 (ISSN) Shamloofard, M ; Hosseinzadeh, A ; Movahhedy, M. R ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    Finite element analysis of huge and/or complicated structures often requires long times and large computational expenses. Superelements are huge elements that exploit the deformation theory of a specific problem to provide the capability of discretizing the problem with minimum number of elements. They are employed to reduce the computational cost while retaining the accuracy of results in FEM analysis of engineering problems. In this research, a new shell superelement is presented to study linear/nonlinear static and free vibration analysis of spherical structures with partial or full spherical geometries that exist in many industrial applications. Furthermore, this study investigates the...