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tahmasbi-nejad--m--a
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VSPACE: VNF simultaneous placement, admission control and embedding
, Article IEEE Journal on Selected Areas in Communications ; Volume 36, Issue 3 , 2018 , Pages 542-557 ; 07338716 (ISSN) ; Parsaeefard, S ; Maddah Ali, M. A ; Mahmoodi, T ; Khalaj, B. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
In future wireless networks, network functions virtualization lays the foundations for establishing a new dynamic resource management framework to efficiently utilize network resources. In this paper, a network service can be viewed as a chain of virtual network functions (VNFs), called a service function chain (SFC), served via placement, admission control (AC), and embedding into network infrastructure, based on the resource management objectives and the state of network. To fully exploit such a potential and reach higher network performance, resource management stages should be jointly performed. To this end, two main challenges are: how to present a system model that formulates the...
On storage allocation in cache-enabled interference channels with mixed CSIT
, Article 2017 IEEE International Conference on Communications Workshops, ICC Workshops 2017, 21 May 2017 through 25 May 2017 ; 2017 , Pages 1177-1182 ; 9781509015252 (ISBN) ; Shariatpanahi, S. P ; Khalaj, B. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Recently, it has been shown that in a cache-enabled interference channel, the storage at the transmit and receive sides are of equal value in terms of Degrees of Freedom (DoF). This is derived by assuming full Channel State Information at the Transmitter (CSIT). In this paper, we consider a more practical scenario, where a training/feedback phase should exist for obtaining CSIT, during which instantaneous channel state is not known to the transmitters. This results in a combination of delayed and current CSIT availability, called mixed CSIT. In this setup, we derive DoF of a cache-enabled interference channel with mixed CSIT, which depends on the memory available at transmit and receive...
Performance Improvement of Content Delivery Wireless Networks
, M.Sc. Thesis Sharif University of Technology ; Hossein Khalaj, Babak (Supervisor)
Abstract
Nowadays, enormous amounts of data are transferred through data communication networks every day in order to fulfill end users’ demands all over the world.The capacities of the links between network nodes, or in other words, the amount of bandwidth available to carry data is undoubtedly one of the most expensive resources as well as the one of most importance which not only plays an essential role in communicating information packets over such a vast network, but is a major determinant of Quality of Service (QoS) in terms of rapidity as well. The idea of using cache memories to optimize network bandwidth consumption laid the foundation for developing Content Delivery Networks (CDNs). In such...
Formation Control of Networked Autonomous Aerial Robots Subject to False Data Injection
, Article ICRoM 2024 - 12th RSI International Conference on Robotics and Mechatronics ; 2024 , Pages 28-33 ; 979-833152973-4 (ISBN) ; Attar, M ; Sharif University of Technology
2024
Abstract
This study investigates the leader-following formation control problem for the networked second-order autonomous arial robot systems under directed topology. It is assumed that the leader's velocity is time varying and formation control will be achieved under the assumption. The formation controller will be designed to form the desired formation of all followers and reached the consensus of velocity. Moreover, it has assumed that agents may expose to a false data injection as a cyber-attack and this affair can affect the transferred sensor information that agents share with each other and break the formation. Finally, a Kalman filter and a chi-square anomaly detector is proposed to detect...
Critical graphs in index coding
, Article IEEE International Symposium on Information Theory - Proceedings ; 2014 , p. 281-285 ; Shahrasbi, A ; Gohari, A ; Sharif University of Technology
2014
Abstract
In this paper we define critical graphs as minimal graphs that support a given set of rates for the index coding problem, and study them for both the one-shot and asymptotic setups. For the case of equal rates, we find the critical graph with minimum number of edges for both one-shot and asymptotic cases. For the general case of possibly distinct rates, we show that for one-shot and asymptotic linear index coding, as well as asymptotic non-linear index coding, each critical graph is a union of disjoint strongly connected subgraphs (USCS). On the other hand, we identify a non-USCS critical graph for a one-shot non-linear index coding problem. In addition, we show that the capacity region of...
Optimum power of a nonlinear piezomagnetoelastic energy harvester with using multidisciplinary optimization algorithms
, Article Journal of Intelligent Material Systems and Structures ; 2020 ; Jamshiddoust, A ; Farrokhabadi, A ; Sharif University of Technology
SAGE Publications Ltd
2020
Abstract
Energy-harvesting devices have been widely used to generate electrical power. Through the use of energy harvesting techniques, ambient vibration energy can be captured and converted into usable electricity in order to create self-powering systems. In the present study, to further improve the efficiency of energy-harvesting devices, a nonlinear piezomagnetoelastic energy harvester is proposed in two different configurations that is parallel and series. In order to optimize the generated electrical power, the physical parameters of the harvester are chosen as the design variables. Classical and Metaheuristic algorithms, namely, random search, genetic algorithm, and simulated annealing are...
Optimum power of a nonlinear piezomagnetoelastic energy harvester with using multidisciplinary optimization algorithms
, Article Journal of Intelligent Material Systems and Structures ; Volume 32, Issue 8 , 2021 , Pages 889-903 ; 1045389X (ISSN) ; Jamshiddoust, A ; Farrokhabadi, A ; Sharif University of Technology
SAGE Publications Ltd
2021
Abstract
Energy-harvesting devices have been widely used to generate electrical power. Through the use of energy harvesting techniques, ambient vibration energy can be captured and converted into usable electricity in order to create self-powering systems. In the present study, to further improve the efficiency of energy-harvesting devices, a nonlinear piezomagnetoelastic energy harvester is proposed in two different configurations that is parallel and series. In order to optimize the generated electrical power, the physical parameters of the harvester are chosen as the design variables. Classical and Metaheuristic algorithms, namely, random search, genetic algorithm, and simulated annealing are...
A new approach to multi-objective optimisation method in PEM fuel cell
, Article International Journal of Sustainable Energy ; Volume 34, Issue 5 , Jul , 2015 , Pages 283-297 ; 14786451 (ISSN) ; Hoseini, A ; Roshandel, R ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
This paper presents an optimisation model for polymer electrolyte membrane fuel cell system based on simultaneous power maximisation and cost minimisation. The results show that, by employing appropriate relation between the objectives, the innovative design could be proposed. Genetic algorithm is applied to solve the optimisation problem. Power maximisation results reveal that at maximum amount of power (1.95 kW), unit cost of energy is $0.64. In contrast, minimisation of cost decreases unit cost of energy to $0.33. In this condition, output power is reduced approximately to 0.93 kW. To consider both optimisation problems concurrently, weighting method and Pareto set are employed. Our...
High-performance enzyme-free glucose sensor with Co-Cu nanorod arrays on Si substrates
, Article Recent Patents on Biotechnology ; Volume 12, Issue 2 , 2018 , Pages 126-133 ; 18722083 (ISSN) ; Yazdanpanah, A ; Karponis, D ; Aghabarari, B ; Tahmasbi, M ; Seifalian, A ; Mozafari, M ; Sharif University of Technology
Bentham Science Publishers B.V
2018
Abstract
Background: Glucose sensors have been extensively researched in patent studies and manufactured a tool for clinical diabetes diagnosis. Although some kinds of electrochemical enzymatic glucose sensors have been commercially successful, there is still room for improvement, in selectivity and reliability of these sensors. Because of the intrinsic disadvantages of enzymes, such as high fabrication cost and poor stability, non-enzymatic glucose sensors have recently been promoted as next generation diagnostic tool due to their relatively low cost, high stability, prompt response, and accuracy. Objective: In this research, a novel free standing and binder free non-enzymatic electrochemical sensor...
Using sliding mode control to adjust drum level of a boiler unit with time varying parameters
, Article ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, ESDA2010, 12 July 2010 through 14 July 2010, Istanbul ; Volume 5 , 2010 , Pages 29-33 ; 9780791849194 (ISBN) ; Bakhtiari Nejad, F ; Saffar Avval, M ; Alasty, A
2010
Abstract
Stable control of water level of drum is of great importance for economic operation of power plant steam generator systems. In this paper, a linear model of the boiler unit with time varying parameters is used for simulation. Two transfer functions between drum water level (output variable) and feed-water and steam mass rates (input variables) are considered. Variation of model parameters may be arisen from disturbances affecting water level of drum, model uncertainties and parameter mismatch due to the variant operating conditions. To achieve a perfect tracking of the desired drum water level, two sliding mode controllers are designed separately. Results show that the designed controllers...
Synthesis and characterization of bioactive glass/forsterite nanocomposites for bone and dental implants
, Article Ceramics - Silikaty ; Volume 56, Issue 4 , 2012 , Pages 331-340 ; 08625468 (ISSN) ; Yazdanpanah, A ; Moztarzadeh, F ; Ravarian, R ; Moztarzadeh, Z ; Tahmasbi, M ; Mozafari, M ; Sharif University of Technology
2012
Abstract
In this research, bioactive glass (BG) of the type CaO-P2O 5-SiO2 and nanocrystalline forsterite (NF) bioceramic were successfully synthesized via sol-gel processing method. Heat-treatment process was done to obtain phase-pure nanopowders. After characterization of each sample, the nanocomposite samples were prepared by cold pressing method and sintered at 1000°C. The samples were fully characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) analyses. The average nanocrystallite size was determined using the Debye-Scherrer's formula 19.6 nm. The bioactivity was examined in vitro...
Trajectory control of autonomous mobile robots considering disturbance with machine learning agents
, Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 45, Issue 6 , 2023 ; 16785878 (ISSN) ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2023
Abstract
Mobile robots as automatic machines have the capability to move around various environments and have considered because of wide range of applications in the industrial settings. It is vital for a mobile robot to determine its errors in indeterminate conditions and provide a robust and high performance controller along with trajectory control. Hence, the research has attempted to give a learning-based controller method for wheeled mobile robots in the presence of disturbance. The proposed method, use LQR controller and the Bat algorithm based on machine learning agents to calculate and identify control errors and satisfy the stability. The wheeled mobile robot should track the reference path...
Chaos control in networked permanent magnet synchronous motor using Lyapunov-based model predictive subject to data loss
, Article Engineering Reports ; Volume 6, Issue 5 , 2024 ; 25778196 (ISSN) ; Sharif University of Technology
2024
Abstract
This study investigates the chaos control in the permanent magnet synchronous motor (PMSM) using a Lyapunov-based model predictive approach subject to data loss. PMSM, as a rich nonlinear dynamic, can demonstrate chaotic behavior when its parameters are in a certain area. Thus, the performance of the system will degrade in this condition. Moreover, in some networked applications, especially in the modern automation industry, data can be lost at the sensor-controller and controller-actuator links. It will lead the system to illustrate the chaotic behavior. Thus, by assuming a PMSM under data loss, a Lyapunov-based predictive model is applied to control the chaos in the PMSM in the presence of...
Introduction of clinical, simulation-based software for medical sciences teachings
, Article Procedia Engineering ; Volume 29 , 2012 , Pages 43-47 ; 18777058 (ISSN) ; Edalat-Nejad, M ; Edalat Nejad, N ; Edalatnejad, M ; Sharif University of Technology
2012
Abstract
Simulation is the gold standard for training in aviation and trauma medicine. Now it is available for diseases diagnosis and treatment. With simulation, clinicians can practice their art in a realistic, consequence free environment, combining both theory and practice in a comprehensive program. Method and materials - In the virtual clinical environment of "VPsoft mentor" software, the practitioner reviews a patient's history, orders laboratory tests and procedures, interprets findings, renders diagnoses, and prescribes medication. Every diagnostic or treatment decision the clinician makes for the patient is analyzed by E-mentor, providing instant feedback.Results - This software have been...
Rapid removal of heavy metal ions from aqueous solutions by low cost adsorbents
, Article International Journal of Global Environmental Issues ; Volume 12, Issue 2-4 , 2012 , Pages 318-331 ; 14666650 (ISSN) ; Rohani Bastami, T ; Tahmasbi, M ; Zabihi, M ; Sharif University of Technology
Interscience
2012
Abstract
In the present investigation, different agricultural solid wastes namely: eggplant hull (EH), almond green hull (AGH), and walnut shell (WS), that are introduced as low cost adsorbents, were used for the removal of heavy metals (cobalt, strontium and mercury ions) from aqueous solutions. Activation process and/or chemical treatments using H 2O 2 and NH 3 were performed on these raw materials to increase their adsorption performances. The effectiveness of these adsorbents was studied in batch adsorption mode under a variety of experimental conditions such as: different chemical treatments, various amounts of adsorbents, initial metal-ion concentrations, pH of solutions, contact times, and...
Investment and dividend dynamics within business groups: evidence from Iran
, Article Journal of Economic Studies ; Volume 52, Issue 7 , 2024 ; 01443585 (ISSN) ; Ebrahim Nejad, A ; Heidari, M ; Sharif University of Technology
Emerald
2024
Abstract
Purpose: The purpose of our study is to examine the functioning of internal capital markets (ICMs) within business groups in Iran. We document how the ultimate owner's economic interests in affiliated firms influence their investment and dividend policies. Design/methodology/approach: Using hand-collected data on the ownership structures of Iranian firms, we first identify group-affiliated firms using Almeida et al.’s (2011) method. Having identified business groups, we test a number of hypotheses concerning the dynamics of the ICMs and the implications of the ultimate owner’s incentives for affiliated firms’ behavior. Findings: We first demonstrate that investments of group-affiliated firms...
Nonparametric simulation of signal transduction networks with semi-synchronized update
, Article PLoS ONE ; Volume 7, Issue 6 , 2012 ; 19326203 (ISSN) ; Masoudi Nejad, A ; Jalili, M ; Moeini, A ; Sharif University of Technology
2012
Abstract
Simulating signal transduction in cellular signaling networks provides predictions of network dynamics by quantifying the changes in concentration and activity-level of the individual proteins. Since numerical values of kinetic parameters might be difficult to obtain, it is imperative to develop non-parametric approaches that combine the connectivity of a network with the response of individual proteins to signals which travel through the network. The activity levels of signaling proteins computed through existing non-parametric modeling tools do not show significant correlations with the observed values in experimental results. In this work we developed a non-parametric computational...
Discovering dominant pathways and signal-response relationships in signaling networks through nonparametric approaches
, Article Genomics ; Volume 102, Issue 4 , October , 2013 , Pages 195-201 ; 08887543 (ISSN) ; Masoudi Nejad, A ; Jalili, M ; Moeini, A ; Sharif University of Technology
2013
Abstract
A signaling pathway is a sequence of proteins and passenger molecules that transmits information from the cell surface to target molecules. Understanding signal transduction process requires detailed description of the involved pathways. Several methods and tools resolved this problem by incorporating genomic and proteomic data. However, the difficulty of obtaining prior knowledge of complex signaling networks limited the applicability of these tools. In this study, based on the simulation of signal flow in signaling network, we introduce a method for determining dominant pathways and signal response to stimulations. The model uses topology-weighted transit compartment approach and comprises...
Normalized Similarity Index: An adjusted index to prioritize article citations
, Article Journal of Informetrics ; Volume 7, Issue 1 , 2013 , Pages 91-98 ; 17511577 (ISSN) ; Masoudi Nejad, A ; Jalili, M ; Moeini, A ; Sharif University of Technology
2013
Abstract
One of the main applications of citation is to find articles that are relevant to a particular article. However, not all citations are equally relevant to the target article. This paper presents an approach to identify the most relevant citation(s). To this end, the Normalized Similarity Index (NSI) is proposed to quantify the similarity between the source and target of a citation base on the co-citations and references shared by them. To validate the method, NSI was calculated for five citation networks and was compared with the peer review grades for the relevancy between the source and the target articles. The results showed a significant correlation between the NSI ranks and those of...
Improving self-care and health literacy in hemodialysis patients: Using software engineering
, Article Proceedings - 2012 7th International Conference on Computing and Convergence Technology (ICCIT, ICEI and ICACT), ICCCT 2012, 3 December 2012 through 5 December 2012 ; December , 2012 , Pages 317-320 ; 9788994364216 (ISBN) ; Edalat-Nejad, M ; Edalat-Nejad, N ; Sharif University of Technology
2012
Abstract
The use of Computer Science in order to categorize and store information, improve diagnostic and therapeutic procedures, patient education and the training of a skilled labor force, has taken important steps and there are constantly new developments in this area