Provisional Hybrid AC/DC Microgrid Planning

, M.Sc. Thesis Sharif University of Technology Mirzapour, Omid (Author) ; Ehsan, Mehdi (Supervisor)

Abstract

Renewable energy deployment through distributed energy resources is among the central goals of future power systems. Microgrids have proven to be an economically viable soloution for distributed energy resources integration into power system and benefit the customers with uninterrupted power supply. In this context provisional microgrids have been introduced with the main goal of rapid renewable energy sources deployment. Since a considerable portion of renewable enegy resources as well as residential loads are DC and this portion is expected to grow even further, hybrid AC/DC design of provisional microgrids can improve both efficiency and economic benefit by optimal arrangement of AC/DC...

Photovoltaic parameter estimation using heuristic optimization

, Article 2017 IEEE 4th International Conference on Knowledge-Based Engineering and Innovation ; Volume 2018-January , 2018 , Pages 0792-0797 ; 9781538626405 (ISBN) Mirzapour, O ; Karimi Arpanahi, S ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

Photovoltaic (PV) panel accurate modeling is essential for operational studies and generation estimation under actual conditions and power electronic control device designs in grid connected or isolated power systems. Inaccuracy in modeling parameters such as photon's current, diode's saturation current, series and parallel resistances and diodes ideality coefficients causes errors in modeling and simulating photovoltaic panel's operation. In this paper, photovoltaic panel's parameters are estimated according to characteristic curves obtained from experiments. Heuristic optimization methods are utilized to calculate parameters for both singlediode and double-diode models. Results indicate...

Capturing local and global features in medical images by using ensemble cnn-transformer

, Article 2023 13th International Conference on Computer and Knowledge Engineering, ICCKE 2023 ; 2023 , Pages 30-35 ; 979-835033015-1 (ISBN) Mirzapour Kaleybar, J ; Saadat, H ; Khaloo, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2023

Abstract

This paper introduces a groundbreaking classification model called the Controllable Ensemble Transformer and CNN (CETC) for the analysis of medical images. The CETC model combines the powerful capabilities of convolutional neural networks (CNNs) and transformers to effectively capture both high and low frequency features present in medical images. The model architecture comprises three main components: a transformer classification block (TCB), a transposed-convolutional decoder block (TDB), and a convolutional encoder block (CEB). The CEB is responsible for capturing multi-local features at different scales and draws upon components from VGGNet, ResNet, and MobileNet as backbones. By...

Dose Simulation in Different Body Parts in Radiotherapy Using BEAM Monte Carlo Code on Human Phantom and Bench-Marking with TL Dosimetry

, M.Sc. Thesis Sharif University of Technology Mirzapour, Meqdad (Author) ; Sohrabpour, Moustafa (Supervisor) ; Mahdavi, Rabi (Supervisor)

Abstract

In this thesis the calculated dose by corePLAN treatment planning software is compared with the calculated dose from combining BEAMnrc and DOSXYZnrc Monte Carlo codes. First Varian Clinic 2100c/d linear accelerator was simulated and modeling parameters such as electron beam energy and its spatial distribution FWHM were tuned in order for PDD and dose profile curves to have an agreement with less than 2% error with the ion chamber dosimetry. In the second section the derived X-ray beams from the accelerator head simulations were used to calculate dose in different organs of a RANDO phantom. The female RANDO phantom was simulated based on its CT data using DOSXYZnrc code. The CT files of the...

Explain the General Policies of Iran (Government) in the Field of Cryptocurrencies

, M.Sc. Thesis Sharif University of Technology Rostami Baroui, Reza (Author) ; Maleki, Ali (Supervisor) ; Mirzapour, Hossein (Co-Supervisor)

Abstract

This research deals with one of the current issues in the world and in Iran which is called the field of cryptocurrencies. This research has tried to map the situation of cryptocurrencies in the world and then the situation of Iran in this field.In order to understand the situation of Iran in the field of cryptocurrencies, three main questions have been defined. The Questions that first express the nature of Iran's policies and then determine the position of these policies in relation to the conceptual framework, and then it will discover the reason of the adoption of these policies in Iran.Therefore, this research has an exploratory approach and its research method is qualitative. In order...

Explain the General Policies of Iran (Government)in the Field of Cryptocurrencies

, M.Sc. Thesis Sharif University of Technology Rostami Baroui, Reza (Author) ; Maleki, Ali (Supervisor) ; Mirzapour, Hossein (Co-Supervisor)

Abstract

This research deals with one of the current issues in the world and in Iran, which is named the field of cryptocurrencies. Domain that is managed decentrally due to the use of blockchain platform. This decentralization has caused different challenges (security problems, disruption of economic governance, etc.) for governments and has created different advantages and disadvantages for each country. This study seeks to investigate how Iran is facing the challenges in the field of cryptocurrencies. In this research, three main questions have been asked to determine the situation of Iran in the field of cryptocurrencies. In the first question, what are the policies of Iran is questioned and then...

A stochastic aggregate production planning model in a green supply chain: Considering flexible lead times, nonlinear purchase and shortage cost functions

, Article European Journal of Operational Research ; Volume 230, Issue 1 , 2013 , Pages 26-41 ; 03772217 (ISSN) Mirzapour Al-E-Hashem, S. M. J ; Baboli, A ; Sazvar, Z ; Sharif University of Technology

2013

Abstract

In this paper we develop a stochastic programming approach to solve a multi-period multi-product multi-site aggregate production planning problem in a green supply chain for a medium-term planning horizon under the assumption of demand uncertainty. The proposed model has the following features: (i) the majority of supply chain cost parameters are considered; (ii) quantity discounts to encourage the producer to order more from the suppliers in one period, instead of splitting the order into periodical small quantities, are considered; (iii) the interrelationship between lead time and transportation cost is considered, as well as that between lead time and greenhouse gas emission level; (iv)...

A capacitated multi-product dynamic lot-sizing problem by considering expiration dates; a new approach

, Article IFAC Proceedings Volumes (IFAC-PapersOnline) ; 2013 , Pages 152-157 ; 14746670 (ISSN) ; 9783902823359 (ISBN) Mirzapour Al E Hashem, S. M. J ; Sazvar, Z ; Baboli, A ; Rekik, Y ; Akbari Jokar, M ; Sharif University of Technology

2013

Abstract

Although managing and controlling the inventories of perishable products is progressively becoming more important, they are often neglected in lot-sizing research and modeling. This paper studies a new multi-product multi-period dynamic lot sizing problem, where the inventories of products are assumed to be expired at a pre-specified date. For this purpose we assume a retailer that purchases products in large quantities (lot size) from manufacturers, and then sells smaller quantities (or single units) to the consumer. So, the order quantities can be merely an integer multiplier of that product batch size. The retailer also owns a capacitated warehouse. In order to make decisions on "how much...

A new up-to level inventory model for deteriorating products with non-linear holding cost

, Article IFAC Proceedings Volumes (IFAC-PapersOnline) ; 2013 , Pages 1702-1707 ; 14746670 (ISSN) ; 9783902823359 (ISBN) Sazvar, Z ; Rekik, Y ; Akbari Jokar, M. R ; Baboli, A ; Mirzapour Al E Hashem, S. M. J ; Sharif University of Technology

2013

Abstract

Inventory management of deteriorating items faces major challenges by uncertain demand, uncertain lead time, perishability, and high customer service level requirements. So, this issue is extremely important in many corporations today. The periodic up-to level policy for deteriorating products under stochastic demand and stochastic lead time is not paid enough attention up to now. In this paper we propose a new approach to study inventory up-to level policy of deteriorating products under normal distributed demand and lead time by considering service level requirements. To model deterioration process, a non-linear increasing holding cost function is considered. After developing the...

Overexpression of protein kinase Mζ in the hippocampus mitigates alzheimer's disease-related cognitive deficit in rats

, Article Brain Research Bulletin ; Volume 166 , 2021 , Pages 64-72 ; 03619230 (ISSN) Amini, N ; Roosta Azad, R ; Motamedi, F ; Mirzapour Delavar, H ; Ghasemi, S ; Aliakbari, S ; Pourbadie, H. G ; Sharif University of Technology

Elsevier Inc 2021

Abstract

Accumulation of amyloid beta (Aβ) soluble forms in the cerebral parenchyma is the mainstream concept underlying memory deficit in the early phase of Alzheimer's disease (AD). PKMζ plays a critical role in the maintenance of long-term memory. Yet, the role of this brain-specific enzyme has not been addressed in AD. We examined the impact of hippocampal PKMζ overexpression on AD-related memory impairment in rats. Oligomeric form of Aβ (oAβ) or vehicle was bilaterally microinjected into the dorsal hippocampus of male Wistar rats under stereotaxic surgery. One week later, 2 μl of lentiviral vector (108 T.U. / ml.) encoding PKMζ genome was microinjected into the dorsal hippocampus. Seven days...

Maritime Inventory Routing Problem Considering Weather Conditions and Tide at Ports

, Article Transportation Research Record ; Volume 2677, Issue 5 , 2023 , Pages 934-950 ; 03611981 (ISSN) Radan, F ; Fatemi Ghomi, S. M. T ; Mirzapour Al-e-hashem, S. M. J ; Sammak Jalali, M ; Sharif University of Technology

SAGE Publications Ltd 2023

Abstract

The maritime inventory routing problem (MIRP) has gained attention in several aspects during the last decades. The problem has numerous variations, typically instigated from real-world complications. This paper addresses MIRP to meet demand in different ports within the defined planning horizon. A mixed integer nonlinear programming model is developed with respect to different planning and routing constraints, loading/unloading restrictions, wave and wind forces limitations, tide constraints, and ship capacity constraints. To study the effects of wave angle, wind force, and tide, the top ten important ports in Iran and nearby ports have been considered as a sample. Optimization of the ship...

Simulating dynamic plastic continuous neural networks by finite elements

, Article IEEE Transactions on Neural Networks and Learning Systems ; Volume 25, Issue 8 , August , 2014 , Pages 1583-1587 ; ISSN: 2162237X Joghataie, A ; Torghabehi, O. O ; Sharif University of Technology

2014

Abstract

We introduce dynamic plastic continuous neural network (DPCNN), which is comprised of neurons distributed in a nonlinear plastic medium where wire-like connections of neural networks are replaced with the continuous medium. We use finite element method to model the dynamic phenomenon of information processing within the DPCNNs. During the training, instead of weights, the properties of the continuous material at its different locations and some properties of neurons are modified. Input and output can be vectors and/or continuous functions over lines and/or areas. Delay and feedback from neurons to themselves and from outputs occur in the DPCNNs. We model a simple form of the DPCNN where the...

A Deep Learning Approach for Detecting Covid-19 Using the Chest X-Ray Images

, Article Computers, Materials and Continua ; Volume 74, Issue 1 , 2023 , Pages 751-768 ; 15462218 (ISSN) Sadeghi, F ; Rostami, O ; Yi, M. K ; Hwang, S. O ; Sharif University of Technology

Tech Science Press 2023

Abstract

Real-time detection of Covid-19 has definitely been the most widely-used world-wide classification problem since the start of the pandemic from 2020 until now. In the meantime, airspace opacities spreads related to lung have been of the most challenging problems in this area. A common approach to do on that score has been using chest X-ray images to better diagnose positive Covid-19 cases. Similar to most other classification problems, machine learning-based approaches have been the first/most-used candidates in this application. Many schemes based on machine/deep learning have been proposed in recent years though increasing the performance and accuracy of the system has still remained an...

Vertically aligned ZnO@CdS nanorod heterostructures for visible light photoinactivation of bacteria

, Article Journal of Alloys and Compounds ; Vol. 590 , 2014 , pp. 507-513 ; ISSN: 09258388 Zirak, M ; Akhavan, O ; Moradlou, O ; Nien, Y. T ; Moshfegh, A. Z ; Sharif University of Technology

2014

Abstract

Vertically aligned ZnO@CdS nanorod heterostructure films with various loadings of CdS nanoparticle shell were synthesized and applied in photoinactivation of Escherichia coli bacteria under visible light irradiation. While neither the bare ZnO nanorods (with band-gap energy (Eg) of ∼3.28 eV) under visible light irradiation nor the nanorod heterostructures in dark exhibited any significant antibacterial activity, the ZnO@CdS nanorod heterostructures (with Eg ∼2.5-2.6 eV) could successfully inactivate the bacteria under visible light irradiation. Furthermore, it was found that an optimum loading of the CdS shell (corresponding to the effective thickness less than ∼15 nm) is required to achieve...

Metallurgical and mechanical properties of underwater friction stir welds of Al7075 aluminum alloy

, Article Journal of Materials Processing Technology ; Volume 262 , 2018 , Pages 239-256 ; 09240136 (ISSN) Rouzbehani, R ; Kokabi, A. H ; Sabet, H ; Paidar, M ; Ojo, O. O ; Sharif University of Technology

Elsevier Ltd 2018

Abstract

Travel speeds between 25–300 mm/min and tool rotational speeds of 800 and 1250 rpm were employed for this study. The microstructure, mechanical properties and fracture surfaces of the joints were studied. Underwater environment and an increase in travel speed significantly increase the precipitates’ volume fraction, reduce the average grain and precipitate sizes of the weld nugget zones. A critical travel speed of 150 mm/min is attained in underwater welds beyond which the average grain sizes remain relatively the same. Average grain and precipitate sizes have linear relationships with the tool rotational and travel speed ratio. Optimum weld strengths of 396 and 360 MPa were obtained in the...

Pre-threaded hole friction stir spot welding of AA2219/PP-C30S sheets

, Article Journal of Materials Processing Technology ; Volume 273 , 2019 ; 09240136 (ISSN) Paidar, M ; Ojo, O. O ; Moghanian, A ; Karami Pabandi, H ; Elsa, M ; Sharif University of Technology

Elsevier Ltd 2019

Abstract

This paper examines the use of pre-fabricated interlocking arms/threading in enhancing the strength of friction stir spot welded hybrid joints of AA2219/PP-C30S polypropylene polymer by varying parameter combination. The process involves the fabrication of a pre-threaded hole on the Al alloy prior to the joining process, and the threading/crest-pitch profile aids mechanical interlocking. The peak temperature, crest-pitch interlocked profiles, microstructural and mechanical properties of the joints were examined. The results show that an increase in the tool rotational speed increases the thickness of the reaction layer (between the Al and the polymer substrates), the shear-tensile load...

Flexible bactericidal graphene oxide–chitosan layers for stem cell proliferation [electronic resource]

, Article Journal of Applied Surface Science ; 15 May 2014, Volume 301, Pages 456–462 Mazaheri, M ; Akhavan, O ; Simchi, A. (Abdolreza) ; Sharif University of Technology

Abstract

Graphene oxide (GO)–chitosan composite layers with stacked layer structures were synthesized using chemically exfoliated GO sheets (with lateral dimensions of ∼1 μm and thickness of ∼1 nm), and applied as antibacterial and flexible nanostructured templates for stem cell proliferation. By increasing the GO content from zero to 6 wt%, the strength and elastic modulus of the layers increased ∼80% and 45%, respectively. Similar to the chitosan layer, the GO–chitosan composite layers showed significant antibacterial activity (>77% inactivation after only 3 h) against Staphylococcus aureus bacteria. Surface density of the actin cytoskeleton fibers of human mesenchymal stem cells (hMSCs) cultured...

Superparamagnetic zinc ferrite spinel-graphene nanostructures for fast wastewater purification

, Article Carbon ; Vol. 69 , April , 2014 , pp. 230-238 ; ISSN: 00086223 Meidanchi, A ; Akhavan, O ; Sharif University of Technology

2014

Abstract

Superparamagnetic ZnFe2O4/reduced graphene oxide (rGO) composites containing ZnFe2O4 nanoparticles (with ∼5-20 nm sizes) attached onto rGO sheets (with ∼1 μm lateral dimensions) were synthesized by hydrothermal reaction method. By increasing the graphene content of the composite from 0 to 40 wt%, the size as well as the number of the ZnFe2O4 nanoparticles decreased and the saturated magnetization of the composites reduced from 10.2 to 1.8 emu/g, resulting in lower responses to external magnetic fields. Concerning this, the time needed for 90% separation of ZnFe2O4/rGO (40 wt%) composite from its solution (2 mg/mL in ethanol) was found 60 min in the presence of an external magnetic field (∼1...

Visible light-induced photocatalytic reduction of graphene oxide by tungsten oxide thin films

, Article Applied Surface Science ; Volume 276 , 2013 , Pages 628-634 ; 01694332 (ISSN) Choobtashani, M ; Akhavan, O ; Sharif University of Technology

2013

Abstract

Tungsten oxide thin films (deposited by thermal evaporation or sol gel method) were used for photocatalytic reduction of graphene oxide (GO) platelets (synthesized through a chemical exfoliation method) on surface of the films under UV or visible light of the environment, in the absence of any aqueous ambient at room temperature. Atomic force microscopy (AFM) technique was employed to characterize surface morphology of the GO sheets and the tungsten oxide films. Moreover, using X-ray photoelectron spectroscopy (XPS), chemical state of the tungsten oxide films and the photocatalytic reduction of the GO platelets were quantitatively investigated. The better performance of the sol-gel tungsten...

Ethylbenzene dehydrogenation to styrene over fresh and used commercial catalysts

, Article AIChE Annual Meeting, Conference Proceedings ; 2011 ; 9780816910670 (ISBN) Baghalha, M ; Ebrahimpour, O ; Sharif University of Technology

2011

Abstract

Dehydrogenation of ethylbenzene (EB) to produce styrene (ST) monomer is commercially performed over potassium-promoted iron oxide catalysts. Catalyst deactivation due to coke deposition and loss of potassium is a major operation and economic drawback in this process. To better evaluate the performance change of these catalysts over their life-cycle, dehydrogenation of EB to ST over the fresh and used commercial catalysts was experimentally investigated at temperatures from 590 to 639°C under atmospheric pressure. The fresh and the used catalysts were obtained from a styrene plant. The used catalyst had been continuously operated for two years under severe plant conditions. The catalyst...