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#### A new hybrid algorithm to solve bound-constrained nonlinear optimization problems

, Article Neural Computing and Applications ; Volume 32, Issue 16 , 2020 , Pages 12427-12452 ; Rahman, M. S ; Shaikh, A. A ; Akhavan Niaki, S. T ; Bhunia, A. K ; Sharif University of Technology
Springer
2020

Abstract

The goal of this work is to propose a hybrid algorithm called real-coded self-organizing migrating genetic algorithm by combining real-coded genetic algorithm (RCGA) and self-organizing migrating algorithm (SOMA) for solving bound-constrained nonlinear optimization problems having multimodal continuous functions. In RCGA, exponential ranking selection, whole-arithmetic crossover and non-uniform mutation operations have been used as different operators where as in SOMA, a modification has been done. The performance of the proposed hybrid algorithm has been tested by solving a set of benchmark optimization problems taken from the existing literature. Then, the simulated results have been...

#### Involutions on the second duals of group algebras and a multiplier problem

, Article Proceedings of the Edinburgh Mathematical Society ; Volume 50, Issue 1 , 2007 , Pages 153-161 ; 00130915 (ISSN) ; Ghahramani, F ; Sharif University of Technology
2007

Abstract

We show that if a locally compact group G is non-discrete or has an infinite amenable subgroup, then the second dual algebra L1(G) ** does not admit an involution extending the natural involution of L1(G). Thus, for the above classes of groups we answer in the negative a question raised by Duncan and Hosseiniun in 1979. We also find necessary and sufficient conditions for the dual of certain left-introverted subspaces of the space Cb(G) (of bounded continuous functions on G) to admit involutions. We show that the involution problem is related to a multiplier problem. Finally, we show that certain non-trivial quotients of L1(G)** admit involutions

#### ISO Metries between Subspaces of Continuous Functions

, M.Sc. Thesis Sharif University of Technology ; Ranjbar Motlagh, Alireza (Supervisor)
Abstract

Suppose $X$ is a locally compcat Hausdorff space. We denote by $C_0(X)$ the Banach space of all continuous functions real or complex-valued defined on $X$ which vanish at infinity, equipped with the supremum norm. Suppose linear subspace $A$ of $C_0(X)$ is strongly separating, that is, for all pair of distinct points $x_1,x_2 \in X$, there exists $f \in A$ such that $|f(x_1)|\neq |f(x_2)|$. In this thesis, we show that Shilov boundary of $A$ exists and is closure Choquet boundary of $A$. Furthermore, \ we show that a linear isometry $T$ of $A$ onto such a subspace $B$ of $C_0(Y)$ induces a homeomorphism $h$ between two certain subspaces of the Shilov boundaries of $B$ and $A$, sending the...

#### Energy harvesting systems with continuous energy and data arrivals: The optimal offline and heuristic online algorithms

, Article IEEE Journal on Selected Areas in Communications ; Volume 34, Issue 12 , 2016 , Pages 3739-3753 ; 07338716 (ISSN) ; Mirmohseni, M ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016

Abstract

Energy harvesting has been developed as an effective technology for communication systems in order to extend their lifetime. In this paper, we consider a single-user energy harvesting wireless communication system, in which arrival data and harvested energy curves are modeled as continuous functions. Our first goal is to find an offline algorithm, which maximizes the amount of data, which is transmitted to the receiver node by a given deadline. If more than one scheme exists that transmits the maximum data, we choose the one with minimum utilized energy at the transmitter node. We find this optimal algorithm, by showing its properties. Next, we propose an online algorithm for this system and...

#### An optimal transmission policy for energy harvesting systems with continuous curves

, Article 12th International Symposium on Wireless Communication Systems, 25 August 2015 through 28 August 2015 ; Volume 2016-April , 2015 , Pages 411-415 ; 21540217 (ISSN) ; 9781467365406 (ISBN) ; Kaboli, R ; Mirmohseni, M ; Aref, M. R ; Sharif University of Technology
VDE Verlag GmbH

Abstract

Energy harvesting has been developed as an effective technology for communication systems in order to extend the lifetime of these systems. In this work, we consider a single-user energy harvesting wireless communication system, in which both of the arrival data and the harvested energy curves are modeled as continuous functions. Our goal is to find an offline algorithm, which maximizes the amount of data which is transmitted to the receiver node by a given deadline. If more than one scheme exist that transmit the maximum data, we choose the one with minimum utilized energy at the transmitter node

#### Effective potential of longitudinal interactions between microtubule protofilaments

, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 78, Issue 1 , 2008 ; 15393755 (ISSN) ; Hamedani Radja, N ; Ejtehadi, M. R ; Sharif University of Technology
2008

Abstract

An effective potential for longitudinal interactions between adjacent protofilaments in a microtubule is introduced. Our proposed interaction potential is a periodic and continuous function of the offset between two protofilaments, which also incorporates the bending energy of protofilaments. This potential produces the results of atomistic simulations. Further, using the potential, a Monte Carlo simulation gives results for the skew angles of observed structures that are in good agreement with experiments. © 2008 The American Physical Society

#### 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 ; Torghabehi, O. O ; Sharif University of Technology
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...

#### An online transmission policy for energy harvesting systems with data traffic arrival

, Article IWCIT 2016 - Iran Workshop on Communication and Information Theory, 3 May 2016 through 4 May 2016 ; 2016 ; 9781509019229 (ISBN) ; Mirmohseni, M ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016

Abstract

In communications, the nodes with the ability of harvesting energy potentially can prolong the overall network lifetime. In this paper, we consider a single-user energy harvesting wireless communication system, in which arrival data and harvested energy curves are modeled as continuous functions. Our goal is to find an online algorithm for the throughput maximization problem, which only needs the causal information of the arrival processes. We propose a heuristic online algorithm which is efficient for both discrete and continuous models, even when the distributions of harvested energy and arrival data are unknown

#### Probabilistic modeling framework for prediction of seismic retrofit cost of buildings

, Article Journal of Construction Engineering and Management ; Volume 143, Issue 8 , 2017 ; 07339364 (ISSN) ; Mahsuli, M ; Talebiyan, H ; Kashani, H ; Sharif University of Technology
Abstract

This study presents a framework that utilizes Bayesian regression to create probabilistic cost models for retrofit actions. Performance improvement is the key parameter introduced in the proposed framework. The incorporation of this novel feature facilitates the characterization of retrofit cost as a continuous function of the desired performance improvement. Accounting for the performance gained from retrofit enables the use of the models in determining the optimal level of retrofit. Furthermore, accounting for the model uncertainty facilitates the use of the models in risk and reliability analyses. The proposed framework is applied to create seismic retrofit cost models for masonry school...

#### Numerical study of propulsion performance in swimming fish using boundary element method

, Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 39, Issue 2 , 2017 , Pages 443-455 ; 16785878 (ISSN) ; Abbaspour, M ; Sharif University of Technology
Springer Verlag
2017

Abstract

In this paper, hydrodynamic simulation of fish-like swimming for two types of aquatic animals including tuna fish and giant danio is presented. We employ an unsteady three-dimensional inviscid boundary element method including time stepping algorithm to capture the wake sheet and flow features around swimming fish in a straight course. At each time step, an unsteady Bernoulli equation was used to find the pressure distribution and thrust generated by the animal. To couple fluid solver with kinematic equations of flexible body, undulating motions of backbone were defined using a prescribed continuous function. Although the flexible motion mechanism controls the fish swimming but no structural...

#### A variational method for designing adaptive bandlimited wavelets

, Article Signal, Image and Video Processing ; Volume 3, Issue 4 , 2009 , Pages 363-374 ; 18631703 (ISSN) ; Mirzaee, S. M. A ; Sharif University of Technology
2009

Abstract

This paper proposes a new method of estimating an orthogonal bounded spectrum wavelet from a given signal. The method is based on minimizing the distance of the wavelet and the given signal in the sense of the metric of the L2 space. In this method, the amplitude and phase of the mother wavelet are optimized simultaneously. The Lagrange multipliers technique is applied to consider the constraints due to the bounded spectrum wavelet and orthogonality conditions. The variational method reduced the optimal matching problem to the solution of a set of functional equations for the amplitude and phase of the optimal-matched bandlimited wavelet spectrum. Continuous functional equations are written...

#### A variational method for designing wavelets to match a specified signal

, Article Signal Processing ; Volume 88, Issue 10 , 2008 , Pages 2417-2424 ; 01651684 (ISSN) ; Izadnia, S ; Vahedi, M ; Sharif University of Technology
Elsevier
2008

Abstract

In this paper, we have developed an efficient method for obtaining an orthonormal wavelet that is matched to a given signal. The error between the wavelet and the given signal is minimized subject to the constraints of the amplitude and phase of the band-limited wavelet spectrum. To consider the constraints of the minimization problem, the Lagrange multipliers technique is applied. Variational method reduced the optimal matching problem to the solution of a set of functional equations for the amplitude and phase of the wavelet spectrum. Continuous functional equations were written in terms of Fourier coefficients of the phase of the transfer function of the quadrature low pass filter at the...

#### An optimal analytical solution for maximizing expected battery lifetime using the calculus of variations

, Article Integration ; Volume 71 , March , 2020 , Pages 86-94 ; Ejlali, A ; Sharif University of Technology
Elsevier B.V
2020

Abstract

The exponential growth in the semiconductor industry and hence the increase in chip complexity, has led to more power usage and power density in modern processors. On the other hand, most of today's embedded systems are battery-powered, so the power consumption is one of the most critical criteria in these systems. Dynamic Voltage and Frequency Scaling (DVFS) is known as one of the most effective energy-saving methods. In this paper, we propose the optimal DVFS profile to minimize the energy consumption of a battery-based system with uncertain task execution time under deadline constraints using the Calculus of Variations (CoV). The contribution of this work is to analytically calculate the...

#### Application of endurance time method in performance-based design of steel moment frames

, Article Scientia Iranica ; Volume 17, Issue 6 A , 2010 , Pages 482-492 ; 10263098 (ISSN) ; Estekanchi, H. E ; Vafai, A ; Sharif University of Technology
2010

Abstract

In this paper, application of the Endurance Time (ET) method in the performance-based design of steel moment frames is explained from a conceptual viewpoint. ET is a new dynamic pushover procedure that predicts the seismic performance of structures by subjecting them to a gradually intensifying dynamic action and monitoring their performance at various excitation levels. Structural responses at different excitation levels are obtained in a single time-history analysis, thus significantly reducing the computational demand. Results from three analyses are averaged to reduce the random scattering of the results at each time step. A target performance curve is presented based on the required...

#### Neuroplasticity in dynamic neural networks comprised of neurons attached to adaptive base plate

, Article Neural Networks ; Volume 75 , 2016 , Pages 77-83 ; 08936080 (ISSN) ; Shafiei Dizaji, M ; Sharif University of Technology
Elsevier Ltd
2016

Abstract

In this paper, a learning algorithm is developed for Dynamic Plastic Continuous Neural Networks (DPCNNs) to improve their learning of highly nonlinear time dependent problems. A DPCNN is comprised of a base medium, which is nonlinear and plastic, and a number of neurons that are attached to the base by wire-like connections similar to perceptrons. The information is distributed within DPCNNs gradually and through wave propagation mechanism. While a DPCNN is adaptive due to its connection weights, the material properties of its base medium can also be adjusted to improve its learning. The material of the medium is plastic and can contribute to memorizing the history of input-response similar...