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On-line nonlinear dynamic data reconciliation using Extended Kalman Filtering: Application to a distillation column and a CSTR
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 28, Issue 3 , 2009 , Pages 1-14 ; 10219986 (ISSN) ; Mehrabani Zeinabad, A ; Bozorgmehry Boozarjomehry,R ; Sharif University of Technology
Abstract
Extended Kalman Filtering (EKF) is a nonlinear dynamic data reconciliation (NDDR) method. One of its main advantages is its suitability for on-line applications. This paper presents an on-line NDDR method using EKF. It is implemented for two case studies, temperature measurements of a distillation column and concentration measurements of a CSTR. In each time step, random numbers with zero mean and specified variance were added to simulated results by a random number generator. The generated data are transferred on-line to a developed data reconciliation software. The software performs NDDR on received data using EKF method. Comparison of data reconciliation results with simulated...
MASTER: Reclamation of hybrid scratchpad memory to maximize energy saving in multi-core edge systems
, Article IEEE Transactions on Sustainable Computing ; Volume 7, Issue 4 , 2022 , Pages 749-760 ; 23773782 (ISSN) ; Hoseinghorban, A ; Bazzaz, M ; Salehi, M ; Ejlali, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Most modern multi-core edge devices work in outdoor situations with limited power supplies like energy harvester and batteries. Therefore, energy consumption is a fundamental issue in which the memory subsystem has a significant role. Scratchpad memories (SPM) can provide a broad potential for energy saving. Still, due to the insufficient SPM capacity in such edge devices, a rigorous SPM data allocation scheme is necessary to reduce the energy consumption of the memory subsystem. Emerging non-volatile memories (NVMs) are very useful to reduce the energy consumption of the memory subsystem. Compared with SRAM, NVMs have lower leakage power and higher density, but the read and write latencies...
Association Rules Mining in Distributed and Dynamic Databases
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor) ; Mirian Hosseinabadi, Hassan (Supervisor)
Abstract
Classical methods of data mining assume that data is centric, is in memory, and is static, although in reality, most of the systems have a lot of data in distributed and dynamic environments or databases. So, classical algorithms of data mining in such environments lose memory and computation resources. In this case, transferring the whole data to a central server and applying the process centrally is inefficient and is subject to privacy issues. Distributed data mining techniques try to address these problems. Mining association rules is one of the important data mining strategies which mines frequent itemsets, correlation, or random structures among itemsets in transactional databases....
Developing an ordering-based renumbering approach for triangular unstructured grids
, Article Engineering with Computers ; Volume 29, Issue 2 , April , 2013 , Pages 225-243 ; 01770667 (ISSN) ; Fouladi, N ; Sharif University of Technology
2013
Abstract
The unstructured grid generation and employment have become very common in computational fluid dynamics applications since a few decades ago. Comparing with the structured grid data, the unstructured grid has a random data structure known as unstructured data structure (USDS). In this work, we develop a new method to convert the USDS of a triangular unstructured grid to a quasi-structured data structure (QSDS) using an ordering-based renumbering approach. In this method, the unstructured grid data is re-ordered in a manner to represent several bands in the original unstructured grid domain. Each band presents one element layer and two node lines. Then, the indices of elements and nodes are...
Improvement of Routing Security in Ad Hoc Networks Against Several Attacks
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Supervisor)
Abstract
Secure routing is a major key to service maintenance in wireless ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. Wormhole attack is one of the most severe active attacks to mobile ad hoc networks. Noting the resource limitations in such networks, nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a...
Development of an Object Oriented Agent Based Framework for Dynamic
Data Reconciliation
,
M.Sc. Thesis
Sharif University of Technology
;
Bozorgmehri, Ramin
(Supervisor)
Abstract
In this thesis, in the first step, design of an Agent Based framework was accomplished. Agent oriented programming is a kind of programming based on distributed processing by agents in a same location or not. UML was used to design the the agent based framework. To implement the designed framework, C++ programming language was used. Embarcadero C++ Builder IDE was chosen to implement the design. Then the designed framework was used to develop a sofware for data reconciliation. The branch for dynamic data reconciliation of this project was extended. To validate the ability of the sofware, a distillation column model with 7 states was selected. The result of gross error detection and data...
Efficiently computing the smallest axis-parallel squares spanning all colors
, Article Scientia Iranica ; Volume 24, Issue 3 , 2017 , Pages 1325-1334 ; 10263098 (ISSN) ; Mohades, A ; Abam, M. A ; Kazemi, M. R ; Sedighin, S ; Sharif University of Technology
Sharif University of Technology
2017
Abstract
For a set of colored points, a region is called color-spanning if it contains at least one point of each color. In this paper, we first consider the problem of maintaining the smallest color-spanning interval for a set of n points with k colors on the real line, such that the insertion and deletion of an arbitrary point takes O(log2 n) the worst-case time. Then, we exploit the data structure to show that there is O(n log2 n) time algorithm to compute the smallest color-spanning square for a set of n points with k colors in the plane. This is a new way to improve O(nk log n) time algorithm presented by Abellanas et al. [1] when k = !(log n). We also consider the problem of computing the...
SRAM cell stability: a dynamic perspective
, Article IEEE Journal of Solid-State Circuits ; Volume 44, Issue 2 , 2009 , Pages 609-619 ; 00189200 (ISSN) ; Sachdev, M ; Sharif University of Technology
2009
Abstract
SRAM cell stability assessment is traditionally based on static criteria of data stability requiring three coincident points in DC butterfly curves. This definition is based on static (DC) characteristics of the cell transistors. We introduce the dynamic criteria of cell data stability knowing that the cell operates in a dynamic environment alternating between access and non-access conditions. The proposed definition of the dynamic data stability criteria introduces a new bound for the cell static noise margin (SNM). It reveals that the true noise margin of the cell can be made considerably higher than the conventional SNM once the cell access time is sufficiently shorter than the cell...
Fuzzy Adaptive Resonance Theory for content-based data retrieval
, Article 2006 Innovations in Information Technology, IIT, Dubai, 19 November 2006 through 21 November 2006 ; 2006 ; 1424406749 (ISBN); 9781424406746 (ISBN) ; Akbari, H ; Akbarzadeh-T., M. R ; Sharif University of Technology
2006
Abstract
In this paper we propose a content-based text and image retrieval architecture using Fuzzy Adaptive Resonance Theory neural network. This method is equipped with an unsupervised mechanism for dynamic data clustering to deal with incremental information without metadata such as in web environment. Results show noticeable average precision and recall over search results. © 2006 IEEE
Damage Detection and Localization in Structures using Sensitivity of Power Spectral Density Obtained from Dynamic Data and Inverse Vibrations
,
M.Sc. Thesis
Sharif University of Technology
;
Bakhshi, Ali
(Supervisor)
Abstract
In this dissertation, the location and severity of the damage are obtained using a new robust Power Spectral Density (PSD) sensitivity-based model updating method. PSD of structural response is highly sensitive metric to parameter change and provides vast information about the structure. The proposed damage detection method uses the sensitivities of measured responses in frequency domain, for FE model updating in an efficient way, by developing a quasi-linear sensitivity equation of structural response. The system of equations are solved using Least Square method. Only stiffness parameters were updated through model updating and change in mass parameters were neglected. In this study, proper...
An energy efficient 40 Kb SRAM module with extended read/write noise margin in 0.13μm CMOS
, Article IEEE Journal of Solid-State Circuits ; Volume 44, Issue 2 , 2009 , Pages 620-630 ; 00189200 (ISSN) ; Sachdev, M ; Sharif University of Technology
2009
Abstract
Based on the dynamic criteria for data stability, we introduce segmented virtual grounding architecture with extended read, write noise margin to realize a low leakage current, energy efficient SRAM module. The architecture offers subthreshold operation for the entire module, except for the selected segments. In addition, a new operational mode for the SRAM cell is introduced which allows only the bitlines of the selected columns to be discharged in an operation. The stability of the cells is enhanced in both read and write operation by controlling the cell access time and cell supply voltage, respectively. A 2048$, imes,$20 bit eSRAM unit is implemented in a regular 0.13 $muhbox{m} $ CMOS...
Three-dimensional data transfer operators in large plasticity deformations using modified-SPR technique
, Article Applied Mathematical Modelling ; Volume 33, Issue 7 , 2009 , Pages 3269-3285 ; 0307904X (ISSN) ; Gharehbaghi, S. A ; Sharif University of Technology
2009
Abstract
In this paper, the data transfer operators are developed in 3D large plasticity deformations using superconvergent patch recovery (SPR) method. The history-dependent nature of plasticity problems necessitates the transfer of all relevant variables from the old mesh to new one, which is performed in three main stages. In the first step, the history-dependent internal variables are transferred from the Gauss points of old mesh to nodal points. The variables are then transferred from nodal points of old mesh to nodal points of new mesh. Finally, the values are computed at the Gauss points of new mesh using their values at nodal points. As the solution procedure, in general, cannot be...
Applying flow zone index approach and artificial neural networks modeling technique for characterizing a heterogeneous carbonate reservoir using dynamic data: Case Study of an Iranian reservoir
, Article Society of Petroleum Engineers - Trinidad and Tobago Energy Resources Conference 2010, SPE TT 2010, 27 June 2010 through 30 June 2010 ; Volume 2 , June , 2010 , Pages 677-690 ; 9781617388859 (ISBN) ; Kharrat, R ; Matin, M ; Sharif University of Technology
2010
Abstract
Although static characterization of reservoirs is an inevitable part of any reservoir studies, the most robust models of the reservoirs can be obtained through integrating static and dynamic data. The following study which is done in a heterogeneous carbonate reservoir utilizes the capillary pressure and relative permeability data to verify the task of static rock typing and investigate the role of hydraulic units in capillary pressure and relative permeability modeling. For this purpose, at first, various rock typing techniques are applied to the field data to seek the best method which has the most consistency with capillary pressure curves. Using Desouky method which is based on hydraulic...