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Optimum hello interval for a connected homogeneous topology in mobile wireless sensor networks
, Article Telecommunication Systems ; Volume 52, Issue 4 , 2013 , Pages 2475-2488 ; 10184864 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2013
Abstract
Topology of a mobile wireless sensor/ad hoc network is prone to link breakages due to node mobility which compels the periodic re-construction of the topology in so called "hello" intervals. The problem addressed in this paper is determining the maximum "hello" interval preserving the connectivity of a homogeneous topology with high probability. In order to study the optimum "hello" interval, statistical topology lifetime (STL) is formally defined as a value of "hello" interval that ensures statistical connectivity with a given threshold. Temporal properties of the topology are studied based on two phenomena; one concerning a connectivity phase transition with time and the other one...
The impact of dispersed PV generation on ramp rate requirements
, Article 2012 11th International Conference on Environment and Electrical Engineering, EEEIC 2012 - Conference Proceedings, 18 May 2012 through 25 May 2012, Venice ; 2012 , Pages 977-982 ; 9781457718281 (ISBN) ; Dehghanian, P ; Moeini-Aghtaie, M ; Abbaspour, A ; Sharif University of Technology
IEEE
2012
Abstract
PV generation variability and uncertainty significantly influence operation of the power systems with high penetration of PV sources. The potential impact of distributed PV generation on ramp rate requirements in the IEEE 24-bus system is evaluated in this paper. PV generation and load are, here, probabilistically modeled using actual data and curve fitting approach. Probabilistic unit commitment (UC) based on unit de-commitment method combined with two point estimate method (2-PEM) is used to determine the ramp rate required to compensate for the PV power fluctuations. The proposed method considers stochastic factors and their effects on the dispatch results. Two scenarios are studied to...
Incorporating large-scale distant wind farms in probabilistic transmission expansion planning-part II: Case studies
, Article IEEE Transactions on Power Systems ; Volume 27, Issue 3 , February , 2012 , Pages 1594-1601 ; 08858950 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Sharif University of Technology
2012
Abstract
This paper is the second part of a two-paper set which comprehensively sets forth an innovative approach in transmission grid reinforcement studies in the presence of wind energy. Part I thoroughly defined the theory and algorithms. Here, to trace the feasibility of the proposed algorithm, three different case studies are implemented on the 24-Bus IEEE Reliability Test System (IEEE-RTS). The optimal solutions in Pareto fronts of different cases are reached, analyzed, and the final solution (optimal plan) of each case is obtained using the fuzzy decision making method. Moreover, in order to analyze the effects of variations in the large-scale wind farm generation on the transmission expansion...
Incorporating a novel confidence scoring method in a Persian spoken dialogue system
, Article SPA 2011 - Signal Processing: Algorithms, Architectures, Arrangements, and Applications - Conference Proceedings, 29 September 2011 through 30 September 2011, Poznan ; September , 2011 , Pages 74-78 ; 9781457714863 (ISBN) ; Sameti, H ; Babaali, B ; Sharif University of Technology
2011
Abstract
Reliability assessment of phonemes, syllabi, words, concepts or utterances has become the key feature of Automatic Speech Recognition (ASR) engines in order to make a decision to accept or reject a hypothesis. In this paper, we propose utterance-level confidence annotation based on combination of features extracted from multiple knowledge sources in Persian language. The experiment was conducted first to examine the performance of individual features, then to combine them using statistical data analysis and density estimation methods to assign a confidence score to utterances. Using the data collected from a Persian spoken dialogue system, we show that combining features from independent...
Optimising operational cost of a smart energy hub, the reinforcement learning approach
, Article International Journal of Parallel, Emergent and Distributed Systems ; Volume 30, Issue 4 , Oct , 2015 , Pages 325-341 ; 17445760 (ISSN) ; Sheikhi, A ; Ranjbar, A. M ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
The concept of smart grid (SG) has been introduced to improve the operation of the power systems. In modern structures of power systems, different reasons prompt researchers to suggest integrated analysis of multi-carrier energy systems. Considering synergy effects of the couplings between different energy carriers and utilising intelligent technologies for monitoring and controlling of energy flow may change energy system management in the future. In this paper, we propose a new solution which is entitled smart energy hub (SEH) that models a multi-carrier energy system in a SG. SEH solutions allow homeowners to manage their energy consumption to reduce their electricity and gas bill. We...
Probabilistic multi-objective transmission investment and expansion planning
, Article International Transactions on Electrical Energy Systems ; Volume 25, Issue 9 , September , 2015 , Pages 1884-1904 ; 20507038 (ISSN) ; Hosseini, S. H ; Moeini Aghtaie, M ; Sharif University of Technology
John Wiley and Sons Ltd
2015
Abstract
In market-based planning studies, the financial aspects of transmission grids have been posed as a major challenge since these are important keys to provide a non-discriminative and competitive environment for energy market participants. In this respect, this paper proposes a probabilistic multi-objective transmission expansion planning algorithm considering private investors' preferences, technical concerns, and random nature of power system uncertainties. The combination of Non-Dominated Sorting Genetic Algorithm II, as a widely-used robust multi-objective optimization technique, and point estimation method is employed to handle non-commensurable probabilistic objective functions. The IEEE...
Parameter estimation of a mathematical model describing the cardiovascular-respiratory interaction
, Article Computing in Cardiology, 6 September 2015 through 9 September 2015 ; Volume 42 , 2015 , Pages 617-620 ; 23258861 (ISSN) ; 9781509006854 (ISBN) ; Hidalgo Muñoz, A. R ; Zarzoso, V ; Zahedi, E ; Murray A ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
Short-term interaction between heart rate (HR) and physiological measures like blood pressure and respiration reveals relevant information about autonomic nervous system (ANS) function. Complex mathematical models for describing their couplings have been proposed in the literature. However, an accurate estimation of their parameters in an inverse modeling problem is crucial to extract reliable ANS related indices. This study considers a physiologically-based model of the cardiovascular-respiratory system and ANS control that presents the neural and mechanical effects of respiration separately. The estimation method is evaluated on synthetic signals. An accurate estimation of the...
Probabilistic energy flow analysis of multi-carrier energy system in the presence of energy DR programs
, Article 2019 Smart Gird Conference, SGC 2019, 18 December 2019 through 19 December 2019 ; 2019 ; 9781728158945 (ISBN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In recent years, a great deal of attention has been paid to multi-energy systems that improve energy efficiency and reliability. In this respect, this paper examines the issue of energy flow of these systems in a probabilistic context in the presence of energy responsive programs. Responsive energy programs are provided by system operator of multi-carrier energy to manage these networks where energy customers can participate in it. The probabilistic method used is 2m + 1 point estimation method, which has high speed and high accuracy. The presented numerical results show the impact of each responsive energy program on the cost of operating a multi-carrier system. © 2019 IEEE
Vehicle identification sensors location problem for large networks
, Article Journal of Intelligent Transportation Systems: Technology, Planning, and Operations ; Volume 23, Issue 4 , 2019 , Pages 389-402 ; 15472450 (ISSN) ; Shafahi, Y ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
Finding the optimal location for sensors is a key problem in flow estimation. There are several location models that have been developed recently for vehicle identification (ID) sensors. However, these location models cannot be applied to large networks because there are many constraints and integer variables. Based on a property of the location problem for vehicle ID sensors, given the initial vehicle ID sensors that are pre-installed and fixed on the network, this article presents a solution that greatly reduces the size of this location problem. An applied example demonstrates that when 8% of the arcs from a real network that are randomly selected have a vehicle ID sensor, the reductions...
Estimation of near-field characteristics of tsunami generation by submarine landslide
, Article Ocean Engineering ; Volume 35, Issue 5-6 , 2008 , Pages 545-557 ; 00298018 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2008
Abstract
Underwater landslide can trigger impulsive waves with high amplitude and run-up, which may cause substantial damage. In this work, the experimental investigations are performed to study the impulsive wave characteristics caused by underwater landslides. The effects of landslide geometry and kinematics on wave characteristics are studied by performing 84 laboratory experiments. The influences of thickness, volume and shape of failure mass on the characteristics of initial wave are discussed. The impacts of water body conditions such as the slope of sliding bed and the initial submergence of underwater landslide are also examined. The present experimental data as well as the available data in...
Application of a kinematics-driven approach in human spine biomechanics during an isometric lift
, Article Scientia Iranica ; Volume 15, Issue 5 , 2008 , Pages 596-612 ; 10263098 (ISSN) ; Shirazi-Adl, A ; Bazrgari, B ; Parnianpour, M ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
Effective prevention and treatment management of spinal disorders can only be based on accurate estimation of muscle forces and spinal loads during various activities such as lifting. The infeasibility of experimental methods to measure muscle and spinal loads has prompted the use of biomechanical modeling techniques. A major shortcoming in many previous and current models is the consideration of equilibrium conditions only at a single cross section, rather than along the entire length of the spine, when attempting to compute muscle forces and spinal loads. The assumption of extensor global muscles with straight rather than curved paths and of the spinal segments as joints with no...
A distributed density estimation algorithm and its application to naive Bayes classification
, Article Applied Soft Computing ; Volume 98 , 2021 ; 15684946 (ISSN) ; Bashiri, M. A ; Beigy, H ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
We consider the problem of learning a density function from observations of an unknown underlying model in a distributed setting, where the observations are partitioned into different sites. Applying commonly used density estimation methods such as Gaussian Mixture Model (GMM) or Kernel Density Estimation (KDE) to distributed data leads to an extensive amount of communication. A familiar approach to address this issue is to sample a small subset of data and collect them into a central node to run the density estimation algorithms on them. In this paper, we follow an alternative to the sub-sampling approach by proposing the nested Log-Poly model. This model provides an accurate density...
Optimal tuner selection using Kalman lter for a real-time modular gas turbine model
, Article Scientia Iranica ; Volume 27, Issue 2 , 2021 , Pages 806-818 ; 10263098 (ISSN) ; Vossughi, G ; Alasty, A ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
In this study, a real-time exible modular modeling approach to simulating the dynamic behavior of gas turbine engines based on nonlinear thermodynamic and dynamic laws is addressed. The introduced model, which is developed in the Matlab-Simulink environment, is an object-oriented high-speed real-time computer model and is capable of simulating the dynamic behavior of a broad group of gas turbine engines due to its modular structure. Moreover, a Kalman lter-based model tuning procedure is applied to decrease the modeling errors. Modeling errors are de ned as the mismatch between simulation results and available experimental data. This tuning procedure is an underdetermined estimation problem,...
Lifetable analysis of Spodoptera exigua Hübner on alternate hosts from cotton agroecosystem for estimating annual population build-up
, Article International Journal of Pest Management ; Volume 67, Issue 3 , 2021 , Pages 252-259 ; 09670874 (ISSN) ; Saeed, S ; Chen, T ; Saeed, Q ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
Understanding the population growth patterns of Spodoptera exigua on alternate host plants can provide valuable information for developing an effective pest management program. In this study, using age-specific lifetable indices, we evaluated the role of alternate crops commonly found in cotton agroecosystem of Pakistan to better understand population dynamics of S. exigua. The longest larval and pupal periods (16.35 and 9.95days, respectively) were observed on spinach, while the shortest periods were recorded on okra (13 days) and cauliflower (8.4 days), respectively. Relatively more female moths (61%) were produced on spinach with low rm (0.095) and λ (1.0997) while highest rm (0.120) and...
Lifetable analysis of Spodoptera exigua Hübner on alternate hosts from cotton agroecosystem for estimating annual population build-up
, Article International Journal of Pest Management ; Volume 67, Issue 3 , 2021 , Pages 252-259 ; 09670874 (ISSN) ; Saeed, S ; Chen, T ; Saeed, Q ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
Understanding the population growth patterns of Spodoptera exigua on alternate host plants can provide valuable information for developing an effective pest management program. In this study, using age-specific lifetable indices, we evaluated the role of alternate crops commonly found in cotton agroecosystem of Pakistan to better understand population dynamics of S. exigua. The longest larval and pupal periods (16.35 and 9.95days, respectively) were observed on spinach, while the shortest periods were recorded on okra (13 days) and cauliflower (8.4 days), respectively. Relatively more female moths (61%) were produced on spinach with low rm (0.095) and λ (1.0997) while highest rm (0.120) and...
Non-Destructive estimation of physicochemical properties and detection of ripeness level of apples using machine vision
, Article International Journal of Fruit Science ; Volume 22, Issue 1 , 2022 , Pages 628-645 ; 15538362 (ISSN) ; Nadimi, M ; Abbaspour Gilandeh, Y ; Paliwal, J ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
Nondestructive estimation of physicochemical properties, post-harvest physiology, and level of ripeness of fruits is essential to their automated harvesting, sorting, and handling. Recent research efforts have identified machine vision systems as a promising noninvasive nondestructive tool for exploring the relationship between physicochemical and appearance characteristics of fruits at various ripening levels. In this regard, the purpose of the current study is to provide an intelligent algorithm for estimating two physical properties including firmness, and soluble solid content (SSC), three chemical properties viz. starch, acidity, and titratable acidity (TA), as well as detection of the...
A probabilistic energy management scheme for renewable-based residential energy hubs
, Article IEEE Transactions on Smart Grid ; Volume 8, Issue 5 , 2017 , Pages 2217-2227 ; 19493053 (ISSN) ; Fotuhi Firuzabad, M ; Zareipour, H ; Moeini Aghtaieh, M ; Sharif University of Technology
Abstract
This paper proposes a new framework for home energy management (HEM) in the context of renewable-based residential energy hub using a probabilistic optimization approach. Different energy converters and storages, including combined heat and power, a plug-in hybrid electric vehicle, a heat storage unit, solar panels, and generic household appliances, are considered in the energy hub. The customer's energy cost is considered as the objective of the HEM optimization problem and different operational limits of the energy hub components are modeled as the constraints. The two-point estimate method is incorporated in this paper to model the uncertainty associated with output power of the rooftop...
A Novel Methodology for Reserve and Energy Scheduling Incorporating Vpps in High Penetration of Renewable Resources
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehranifard, Ali (Supervisor) ; Fotuhi Firozabad, Mahmoud (Supervisor)
Abstract
Considering the high penetration of renewable energy resources in modern power systems, independent system operator faces considerable uncertainty and variability in the system under supervision. In this regard, determining and providing the appropriate amount of operational reserve is critical to overcoming uncertainty and variability to have reliable system performance. In practice, power system operators prefer to use deterministic approaches to schedule operational reserve. Such approaches have benefits in simplicity and fast calculations. Nevertheless, increasing share of renewable resources causes a considerable error in these approaches. Therefore, many researchers have proposed...
Probabilistic load flow in correlated uncertain environment using unscented transformation
, Article IEEE Transactions on Power Systems ; Vol. 27, issue. 4 , 2012 , p. 2233-2241 ; ISSN: 08858950 ; Fotuhi-Firuzabad, M ; Aminifar, F ; Sharif University of Technology
Abstract
As a matter of course, the unprecedented ascending penetration of distributed energy resources, mainly harvesting renewable energies, is a direct consequence of environmental concerns. This type of energy resource brings about more uncertainties in power system operation and planning; consequently, it necessitates probabilistic analyses of the system performance. This paper develops a new approach for probabilistic load flow (PLF) evaluation using the unscented transformation (UT) method. The UT method is recognized as a powerful approach in assessing stochastic problems with/without correlated uncertain variables. The capability of the UT method in modeling correlated uncertain variables is...
Estimation of naturally fractured oil reservoir properties using the material balance method
, Article Scientia Iranica ; Volume 21, Issue 3 , 2014 , Pages 781-791 ; ISSN: 10263098 ; Jamshidi, S ; Gholinezhad, S ; Sharif University of Technology
Abstract
In fractured reservoirs, a large variation of permeability due to the presence of fractures leads to changes in the production mechanism compared to conventional reservoirs. Hence, an appropriate model with the ability to describe the reservoir properly can provide a more confident prediction of its future performance. One of the features of a representative model is the number and height of the matrix blocks. The determination of these two parameters is one of the decisive steps in the calculation of an accurate amount of oil production from these reservoirs. In fact, matrix height shows its effect as a gravity force, which is one of the driving mechanisms. If the matrix height is less than...