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Investigation of a radiative sky cooling module using phase change material as the energy storage
, Article Applied Energy ; Volume 321 , 2022 ; 03062619 (ISSN) ; Khalilmoghadam, P ; Behshad Shafii, M ; Moshfegh, A. Z ; Hu, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Radiative sky cooling (RSC) systems have enjoyed a privileged position in the research community due to generating cooling energy without consuming electricity using the open atmospheric window and infrared emission to the sky. However, the system's justification occurs when it reaches a temperature below the minimum 24-hour ambient temperature. This study utilizes phase change materials (PCM) as the energy storage of a hybrid daytime photovoltaic-thermal and nighttime RSC module and investigates the nocturnal cooling energy-saving potential of the system at different phase transition temperatures. After being validated by the experimental data in the literature, the simulated model was used...
Evolving data stream clustering based on constant false clustering probability
, Article Information Sciences ; Volume 614 , 2022 , Pages 1-18 ; 00200255 (ISSN) ; Bagheri Shouraki, S ; Norouzi, Y ; Sharif University of Technology
Elsevier Inc
2022
Abstract
Today's world needs new methods to deal with and analyze the ever-increasingly generated data streams. Two of the most challenging aspects of data streams are (i) concept drift, i.e. evolution of data stream over time, which requires the ability to make timely decisions against the high speed of receiving new data; (ii) limited memory storage and the impracticality of using memory due to the large amount of data. Clustering is one of the common methods to process data streams. In this paper, we propose a novel, fully-online, density-based method for clustering evolving data streams. In recent years, a number of methods have been proposed, which also have the ability to cluster data streams....
Data-driven joint TEP-BESS co-planning scheme to relieve transmission lines congestion: A min-max regret method
, Article Sustainable Energy Technologies and Assessments ; Volume 53 , 2022 ; 22131388 (ISSN) ; Moeini Aghtaie, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Transmission lines congestion has recently been a vital challenge in power systems operation due to the intermittent outputs of renewable energy sources (RES). Therefore, an efficient transmission congestion management (TCM) method should be defined to deal with the congestion issue. This paper aims to propose a simultaneous linearized two-stage TEP-BESS co-planning optimization model to relieve transmission lines congestion. In doing so, a novel TCM structure is suggested in a pool-based deregulated data-driven optimal power flows (D-OPF) by the computationally effective min-max regret method to consider future scenarios of generating units and demanded loads. To improve the efficiency of...
Investigation on various types of ion-exchange membranes in vanadium redox flow batteries: Experiment and modeling
, Article Journal of Energy Storage ; Volume 54 , 2022 ; 2352152X (ISSN) ; Rahimi, M ; Molaei Dehkordi, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Choosing the appropriate ion exchange membrane in vanadium redox flow batteries plays an important role in achieving optimal system performance. In this article, the implementation of commercial cation exchange membranes (Nafion 115, Nafion 117, and Nafion 212), anion exchange membranes (FAP 450 and QA-PFE), and the combination of them are investigated. In this regard, the effects of membrane type, thickness, electrical conductivity, and the transfer of vanadium species at different current densities are examined carefully. In addition, the influences of the flow rate and the concentration of electrolytes are investigated using a comprehensive developed model. The model predictions are...
A novel decision-making methodology for materials selection under uncertainty: modified fuzzy logic method
, Article Soft Computing ; Volume 26, Issue 22 , 2022 , Pages 12093-12114 ; 14327643 (ISSN) ; Abedian, A ; Razaghian, P ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
In this research work, a modified fuzzy approach referred to as modified fuzzy logic method (MFLM) is proposed to more conveniently solve intricate decision-making problems under uncertainty and data deficiency. The method resolves major drawbacks like inaccuracy, complexity, and a high volume of computational efforts with the existing approaches for the mentioned problems. Here, MFLM is applied to materials selection for a cryogenic storage tank and a gas turbine blade, which are standard engineering problems used for verification by researchers, and the ranking results are compared with the state-of-the-art techniques in the literature, such as the conventional fuzzy logic method....
Downscaling of the flood discharge in a probabilistic framework
, Article Journal of Hydro-Environment Research ; Volume 43 , 2022 , Pages 10-21 ; 15706443 (ISSN) ; Gharehtoragh, M. A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Many modeled and observed data are in coarse resolution, which are required to be downscaled. This study develops a probabilistic method to downscale 3-hourly runoff to hourly resolution. Hourly data recorded at the Poldokhtar Stream gauge (Karkheh River basin, Iran) during flood events (2009–2019) are divided into two groups including calibration and validation. Statistical tests including Chi-Square and Kolmogorov–Smirnov test indicate that the Burr distribution is proper distribution functions for rising and falling limbs of the floods’ hydrograph in calibration (2009–2013). A conditional ascending/descending random sampling from the constructed distributions on rising/falling limb is...
Investigating performance of a new design of forced convection solar dryer
, Article Sustainable Energy Technologies and Assessments ; Volume 50 , 2022 ; 22131388 (ISSN) ; Sefid, M ; Almutairi, K ; Mostafaeipour, A ; Ao, H. X ; Hosseini Dehshiri, S. J ; Hosseini Dehshiri, S. S ; Chowdhury, S ; Techato, K ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Drying is a common practice for delaying deterioration, preserving quality, and easier prolonged storage of agricultural products. According to the climatic and geographical conditions of Arsanjan County, Fars, Iran. So far, many studies have been conducted on the design and use of various barriers on absorber plates with the aim of increasing heat exchange and subsequently increasing the efficiency of air heaters and solar dryers. However, the effect of using the metal of the sewing machine bobbin on the performance of these dryers has not been studied yet. Therefore, in this study, for the first time, this metal and also pipes containing PCM (phase change material) were used as a barrier...
CL-MLSP: The design of a detection mechanism for sinkhole attacks in smart cities
, Article Microprocessors and Microsystems ; Volume 90 , 2022 ; 01419331 (ISSN) ; Javadpour, A ; Ja'fari, F ; Pinto, P ; Ahmadi, H ; Zhang, W ; Sharif University of Technology
Elsevier B.V
2022
Abstract
This research aims to represent a novel approach to detect malicious nodes in Ad-hoc On-demand Distance Vector (AODV) within the next-generation smart cities. Smart city applications have a critical role in improving public services quality, and security is their main weakness. Hence, a systematic multidimensional approach is required for data storage and security. Routing attacks, especially sinkholes, can direct the network data to an attacker and can also disrupt the network equipment. Communications need to be with integrity, confidentiality, and authentication. So, the smart city and urban Internet of Things (IoT) network, must be secure, and the data exchanged across the network must...
Third order NLO and second hyperpolarizability of functional porphyrin based polyimides
, Article Optical Materials ; Volume 127 , 2022 ; 09253467 (ISSN) ; Khan, Q. U ; Mahmood, Q ; Ghafoor, F ; Alsaab, H. O ; Shah, S. A. A ; Athir, N ; Iqbal, A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Porphyrin-POM hybrid materials with excellent NLO properties are supposed to be a worthy entrant for forthcoming telecommunication, optical fibers, optical data storage and optical limiting devices, but due to adverse solubility problems, they are replaced by polymeric materials. Herein, we assessed third order NLO and second hyperpolarizability of porphyrin-polyimide compounds (NH-PI and Zn-PI) synthesized from the reaction of 4,4ʹ-hexafluoroisopropylidene-diphthalic anhydride (6FDA) with C44H32N6 (NH-DATPP) and C44H30N4Zn (Zn-DATPP) porphyrins under ambient conditions. The Z-scan measurement of these compounds revealed reverse saturation absorption as well as self-defocusing performance....
Modeling the dual-fuel combustion of porous lycopodium particles and diesel using an analytical simulation framework
, Article Journal of Analytical and Applied Pyrolysis ; Volume 163 , 2022 ; 01652370 (ISSN) ; Akbari, S ; Faghiri, S ; Sadeghi, S ; Xu, F ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this paper, a comprehensive analytical study is performed to assess the lycopodium-diesel dual-fuel combustion system in counter-flow premixed configuration. The system is modeled as multiple zones that are coupled together via proper boundary and jump conditions on interfaces. According to the respective reaction and transport phenomena in these zones, conservation equations of mass and energy are derived, non-dimensionalized, and solved by Matlab and Mathematica in an analytical way. The porosity of lycopodium particles and the thermal radiation from the reaction zone and the post-flame zones into the preheating zone are considered, in order to improve the realism and accuracy of the...
A multi-objective framework for distributed energy resources planning and storage management
, Article Applied Energy ; Volume 314 , 2022 ; 03062619 (ISSN) ; Ceylan, O ; Ozdemir, A ; Fotuhi Firuzabad, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The use of energy storage systems (ESS) and distributed generators (DGs) to improve reliability is one of the solutions that has received much attention from researchers today. In this study, we utilize a multi-objective optimization method for optimal planning of distributed generators in electric distribution networks from the perspective of multi-objective optimization. The objective is to improve the reliability of the network while reducing the annual cost and network losses. A modified version of the multi-objective sine–cosine algorithm is used to determine the optimal size, location, and type of DGs and the optimal capacity, location, and operation strategy of the ESS. Three case...
An enterprise-grade open-source data reduction architecture for all-flash storage systems
, Article Performance Evaluation Review ; Volume 50, Issue 1 , 2022 , Pages 59-60 ; 01635999 (ISSN) ; Raaf, P ; Kishani, M ; Salkhordeh, R ; Asadi, H ; Brinkmann, A ; Sharif University of Technology
Association for Computing Machinery
2022
Abstract
Data reduction technologies have proven their effectiveness to decrease the ever-growing demands on storage system capacities, but also introduce new complexity in the system I/O stack that can easily invalidate well-known best practices. In this paper, we conduct an extensive set of experiments on an enterprise all-flash storage (AFS) system equipped with an open-source data reduction module, i.e., RedHat VDO, and reveal novel observations on the performance gap between the state-of-the-art and the optimal AFS stack with integrated data reduction. We then offer cross-layer optimizations to enhance the performance of AFS, which range from deriving new optimal hardware RAID configurations up...
An enterprise-grade open-source data reduction architecture for all-flash storage systems
, Article 2022 ACM SIGMETRICS/IFIP PERFORMANCE Joint International Conference on Measurement and Modeling of Computer Systems, SIGMETRICS/PERFORMANCE 2022, 6 June 2022 through 10 June 2022 ; 2022 , Pages 59-60 ; 9781450391412 (ISBN) ; Raaf, P ; Kishani, M ; Salkhordeh, R ; Asadi, H ; Brinkmann, A ; ACM SIGMETRICS ; Sharif University of Technology
Association for Computing Machinery, Inc
2022
Abstract
Data reduction technologies have proven their effectiveness to decrease the ever-growing demands on storage system capacities, but also introduce new complexity in the system I/O stack that can easily invalidate well-known best practices. In this paper, we conduct an extensive set of experiments on an enterprise all-flash storage (AFS) system equipped with an open-source data reduction module, i.e., RedHat VDO, and reveal novel observations on the performance gap between the state-of-the-art and the optimal AFS stack with integrated data reduction. We then offer cross-layer optimizations to enhance the performance of AFS, which range from deriving new optimal hardware RAID configurations up...
A high-accuracy two-stage deep learning-based resolver to digital converter
, Article 13th Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2022, 1 February 2022 through 3 February 2022 ; 2022 , Pages 71-75 ; 9781665420433 (ISBN) ; Emadaleslami, M ; Nasiri Gheidari, Z ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
High-efficiency Permanent Magnet Synchronous Motors (PMSMs) are widely used in industrial applications. Subsequently, resolvers as position sensors experience increasing usage in the drive of PMSMs. Measuring the rotor's position using a resolver needs a costly Resolver to Digital Converter (RDC). Therefore, in this paper, a software-based, low-cost RDC is presented against the conventional Angle Tracking Observers (ATOs). The proposed RDC is a high-Accuracy two-stage Deep Neural Network (DNN)-based one. In this regard, an overview of the resolvers' function and the general methodology to DNN training is given. Then, the case study is done on the gathered data from the set of the resolver...
Security enhancement of an auditing scheme for shared cloud data
, Article International Journal of Internet Protocol Technology ; Volume 15, Issue 1 , 2022 , Pages 60-68 ; 17438209 (ISSN) ; Attari, M. A ; Asaar, M. R ; Aref, M. R ; Sharif University of Technology
Inderscience Publishers
2022
Abstract
In cloud storage services, public auditing mechanisms allow a third party to verify integrity of the outsourced data on behalf of data owners without the need to retrieve data from the cloud server. In some applications, the identity of data users should be kept private from the third party auditor. Oruta is a privacy preserving public auditing scheme for shared data in the cloud which exploits ring signatures to protect the identity privacy. In this paper, we propose two attacks and demonstrate that the scheme is insecure and a dishonest server can arbitrarily tamper the outsourced data without being detected by the auditor. We also propose a solution to remedy this weakness with the...
Design and implementation of an ultralow-power Ecg patch and smart cloud-based platform
, Article IEEE Transactions on Instrumentation and Measurement ; Volume 71 , 2022 ; 00189456 (ISSN) ; Shayan, M. F ; Vazifeh, A. R ; Rashidi, D ; Hamedani, M. S ; Tavolinejad, H ; Gorji, P ; Razmara, P ; Vaziri, K ; Vashaee, D ; Fakharzadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
This article reports the development of a new smart electrocardiogram (ECG) monitoring system, consisting of the related hardware, firmware, and Internet of Things (IoT)-based web service for artificial intelligence (AI)-assisted arrhythmia detection and a complementary Android application for data streaming. The hardware aspect of this article proposes an ultralow power patch sampling ECG data at 256 samples/s with 16-bit resolution. The battery life of the device is two weeks per charging, which alongside the flexible and slim (193.7 mm times62.4 mm times8.6 mm) and lightweight (43 g) allows the user to continue real-life activities while the real-time monitoring is being done without...
Quantifying lake–aquifer water exchange: the case of Lake Urmia, Iran
, Article Hydrological Sciences Journal ; Volume 67, Issue 5 , 2022 , Pages 725-740 ; 02626667 (ISSN) ; Hosseini, S. M ; Ataie Ashtiani, B ; Nikraftar, Z ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
This study investigated the lake–aquifer hydraulic interactions in Lake Urmia (LU) as the second largest hypersaline lake in the world. Due to the scarcity of hydrogeological data required for modelling, a method based on Darcy’s Law and lake water budget was used to quantify the lake–aquifer interaction. Long-term ground- and satellite-based hydrological datasets over the time frame 2001–2019 were used. Results indicate that the groundwater flux between LU and the aquifers controls 18.74 ± 1.67% of the lake’s water storage. While 10 out of 14 adjacent aquifers recharge LU at a rate of less than 180 m3/m.month, one phreatic aquifer recharges the LU up to 1400 m3/m.month. Two aquifers are...
A lightweight auditing service for shared data with secure user revocation in cloud storage
, Article IEEE Transactions on Services Computing ; Volume 15, Issue 1 , 2022 , Pages 1-15 ; 19391374 (ISSN) ; Attari, M. A ; Asaar, M. R ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
As data sharing has become one of the most popular services offered by cloud storage, designing public auditing mechanisms for integrity of shared data becomes more important. Two problems which arise in shared data auditing include preserving users identity and collusion resistant revocation of users. When data stored at the cloud is shared among a group of users, different users may modify and sign different data blocks which leaks signer identities to the public verifier. Also, when a user is revoked from the group, signatures generated by this user should be re-signed by the cloud server using re-signature keys. In addition, collusion of cloud server and the revoked user should leak no...
Assessment of two-phase relative permeability hysteresis models for oil/water, gas/water and gas/oil systems in mixed-wet porous media
, Article Fuel ; Volume 309 , 2022 ; 00162361 (ISSN) ; Gharavi, A ; Fatemi, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Accurate determination of relative permeability curves and their hysteresis is vital for reliable prediction of the performance of oil and gas reservoirs under enhanced recovery processes. Two out of the three available approaches to simulate three-phase relative permeability hysteresis are based on two-phase hysteresis. A few options (e.g., Carlson, Killough and Jargon models) are available in commercial reservoir simulators to account for hysteresis in relative permeability curves under two-phase flow. These models are based on the assumptions of water-wet state of the rocks, while most of the reservoir rocks are mixed-wet. As a result the aim of the present work is to evaluate the...
A theory for coupled lithium insertion and viscoplastic flow in amorphous anode materials for Li-ion batteries
, Article Mechanics of Materials ; Volume 152 , 2021 ; 01676636 (ISSN) ; Arghavani, J ; Naghdabadi, R ; Brassart, L ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Amorphous lithium metal alloys (LixM, with M=Si, Ge, Sn, …) are attractive anode materials for lithium-ion batteries owing to their high energy-storage capacity and safety characteristics. However, repeated insertion of lithium often leads to chemo-mechanical degradation of the alloy, which can severely reduce the battery capacity and cycle life. Better understanding of the chemo-mechanical response of lithium alloys is needed to guide the design of damage-resistant anode microstructures. In this work, we propose a constitutive theory that couples large, viscoplastic deformations to the insertion and extraction of lithium in amorphous electrode materials. The theory relies on the concept of...