Sharif Digital Repository

Long-term distribution network planning (DNP) is considered as one of the most challenging issues for distribution network operators (DNOs). By increasing EVs in cities, it has appeared some new players such as electric vehicles (EVs) owners and electric vehicle parking lots (EVPLs) owners for DNP. In this article, we conduct a new study on the coupled dynamic expansion problem of EVPLs placement and distribution networks. To reach this goal, at first, EVs driving and charging/discharging behavior as some influential factors is modeled using an efficient probabilistic algorithm. An analytical model is then introduced to estimate the number of EVs in EVPLs at different times. To find out the... 

Site investigations at limited-access project sites often require mobilization of smaller rigs that may not have the reaction mass required to perform soundings to the desired depth. This study explores the feasibility of a new conceptual bio-inspired solution by adapting functional principles from organisms whose primary mode of locomotion is soil burrowing, including razor clams, caecilians, and earthworms. These organisms radially expand a segment of their body to increase the normal radial pressure acting on it to temporarily form an anchor. This study evaluates the dimensions required for self penetration of an idealized bio-inspired probe consisting of a radially expanding shaft and a... 

This paper presents a new robust co-planning model for transmission investment and merchant distributed energy resources (DERs). The problem is formulated from the viewpoint of power system regulators and planners such that they will build the new transmission facilities and identify optimal locations to direct merchant DERs. The proposed model is a tri-level min-max-min optimization problem where the upper, middle, and lower levels are investment decision of transmission lines and DERs, worst case realization of uncertain parameters, and the best actions in order to minimize the operation costs. The model considers the uncertainties associated with future peak load and generation capacity,... 

The present simulation aims to investigate adding NEPCM nanoparticles to water in the natural convection inside a cavity by using FVM method and SIMPLE algorithm. Nano-encapsulated phase change material (NEPCM) consists of a shell and core with phase change property. The NEPCM particles in base fluid have the ability to transfer heat by absorbing and dissipating heat in the liquid-solid phase change state. In this study, the energy wall phenomenon due to the phase change of NEPCM core has appeared that the whose energy transfer strength is proportional to the latent heat of NEPCM core and the thickness of the energy wall. Moreover, the relationship between the energy wall and the heat... 

Given a graph, the sparsest cut problem asks for a subset of vertices whose edge expansion (the normalized cut given by the subset) is minimized. In this paper, we study a generalization of this problem seeking for k disjoint subsets of vertices (clusters) whose edge expansions are small and furthermore, the number of vertices that remained in the exterior of the subsets (outliers) is also small. It is proved in Daneshgar et al. (2012) that this problem is NP-hard for trees. Here, we prove that it can be solved in polynomial time for all weighted trees, provided that the search space is restricted to subsets inducing connected subgraphs. The additional constraint has justifications in... 

Conic shell structures are widely used in aerospace industries. In the literature various models have been proposed to failure analysis of composite materials. Clearly, each model has a favorable range of applications. In this paper tensile, compressive, shear and thermal expansion properties of tape-wounded Carbon/Phenolic composites are firstly measured at various temperatures in range 23–200°C. The captured properties are then taken into account to progressive failure analysis of a conic Carbon/Phenolic structure under internal pressure and thermal loadings. For this end, a particular failure criterion is proposed to predict failure in the composite structures with a reasonable margin of... 

The waist parameter is a particularly important factor for functional expansion in terms of localized orthogonal basis functions. We present a systematic approach to evaluate an asymptotic trend for the optimum waist parameter in truncated orthogonal localized bases satisfying several general conditions. This asymptotic behavior is fully introduced and verified for Hermite - Gauss and Laguerre-Gauss bases. As a special case of importance, a good estimate for the optimum waist in projection of discontinuous profiles on localized basis functions is proposed. The importance and application of the proposed estimation is demonstrated via several optical applications  

Analysis of highly conducting binary gratings in TM polarization has been problematic as the Fourier factorization fails and thus unwanted numerical artifacts appear. The Legendre polynomial expansion method (LPEM) is employed here, and the erroneous harsh variations attributed to the violation of the inverse rule validity in applying the Fourier factorization are filtered out. In this fashion, stable and artifact-free numerical results are obtained. The observed phenomenon is clearly demonstrated via several numerical examples and is explained by inspecting the transverse electromagnetic field profile. © 2009 Optical Society of America  

This chapter describes and discusses Langevin dynamics and the Fokker–Planck equation in higher dimension, and discrete-time evolution and discrete-time approximation of stochastic evolution equations. We close the chapter with calculations of short-time propagators of d-dimensional Fokker–Planck equation. © 2019, Springer Nature Switzerland AG  

This chapter describes and discusses Langevin dynamics and the Fokker–Planck equation in higher dimension, and discrete-time evolution and discrete-time approximation of stochastic evolution equations. We close the chapter with calculations of short-time propagators of d-dimensional Fokker–Planck equation. © 2019, Springer Nature Switzerland AG  

This paper presents experimental results on the foaming behavior and compressive properties of AlSi7-3 vol.% SiC metal foam. Elemental powders of Al, Si, SiC and TiH2 were mixed, hot compacted and foamed at 750, 780 and 810 °C. It was shown that the addition of fine SiC particles (mean diameter of 3 μm) increases the melt expansion and improves the stability of AlSi7 foam. A less drainage in the cell structure was also noticed. Meanwhile, large irregular cells in the macrostructure and a slight degradation of the mechanical properties under compressive load were observed. © 2007 Elsevier B.V. All rights reserved  

This paper introduces a novel, cost effective visual cryptography scheme suitable for color image transmission over bandwidth constraint channels. Unlike previously proposed schemes, the solution offers perfect reconstruction while producing shares with size smaller than that of the input image. The maximum distance separable (MDS) code principle used in the design allows for the introduction of a flexible framework that compares favorably to competing solutions as it can be seen by examining the experimental results included in this paper. ©2008 IEEE  

The determination of the thermo-mechanical stress field in and around a spherical/ cylindrical inhomogeneity surrounded by a functionally graded (FG) coating, which in turn is embedded in an infinite medium, is of interest. The present work, in the frame work of Boussinesq/Papkovich-Neuber displacement potentials method, discovers the potential functions by which not only the relevant boundary value problems (BVPs) in the literature, but also the more complex problem of the coated inhomogeneities with FG coating and sliding interfaces can be treated in a unified manner. The thermo-elastic fields pertinent to the inhomogeneities with multiple homogeneous coatings and various combinations of... 

Purpose - One major challenge in turbulent flow applications is to control the recirculation zone behind the backward-facing step (BFS). One simple idea to do so is to modify the original BFS geometry, of course, without causing adverse or undesirable impacts on the original characteristics of the primary stream. The main objective of this work is to examine the solidity of the recirculation zone behind several different geometries which are slightly to moderately different from the original BFS geometry. Design/methodology/approach - The implemented modifications cause complicated irregularities at the boundaries of the domain. The experience shows that the mesh distribution around these... 

The current study revealed the effectiveness of polypropylene (PP) fibers and cement to enhance the strength of black cotton soil. PP fibers and cement with different concentrations were mixed with black cotton soil. The strength of PP fiber and cement-based soil samples was measured in terms of unconfined compressive strength (UCS) and California Bearing ratio (CBR). Specimens for UCS and CBR tests were prepared at 2%, 4%, 6% and 8% of cement (by dry weight of soil) and seven percentages of polypropylene fibers i.e. 0.0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 0.6% (by dry weight of soil). Fourier transform infrared (FTIR) analysis confirmed the presence of polypropylene and cement contents in... 

Using the newly introduced asymptotic expansion method to obtain equations of state for hard sphere fluid, new simple equations of state for hard disks based on known virial coefficients are derived. Comparison of the obtained equations of state with computer simulation data shows that they are accurate in the whole fluid region. © 2007 Elsevier B.V. All rights reserved  

Applying flexible variable shape control surfaces (wing and elevator) structures is a way to increase efficiency and maneuverability of the planes, which is recently under research. In this paper, modeling of the flight of an unmanned ultra light plane is discussed. The modeling is done based on a real ultra light plane presented recently. To increase maneuverability of the plane, flexible variable shape structures are designed for the wing and the elevator. In design procedure, having an ultra light plane is considered. The elevator and the wing are used as control surfaces for longitudinal and lateral maneuvers respectively. Shape memory alloys (SMA) are used for reshaping the flexible... 

The current study revealed the effectiveness of polypropylene (PP) fibers and cement to enhance the strength of black cotton soil. PP fibers and cement with different concentrations were mixed with black cotton soil. The strength of PP fiber and cement-based soil samples was measured in terms of unconfined compressive strength (UCS) and California Bearing ratio (CBR). Specimens for UCS and CBR tests were prepared at 2%, 4%, 6% and 8% of cement (by dry weight of soil) and seven percentages of polypropylene fibers i.e. 0.0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 0.6% (by dry weight of soil). Fourier transform infrared (FTIR) analysis confirmed the presence of polypropylene and cement contents in... 

With increment in the penetration of wind energy in power systems, the necessity of considering its impacts on transmission expansion planning (TEP) studies, especially for large scale wind farms, is inevitable. A new multi-objective (MO) optimization transmission expansion planning algorithm considering wind farm generation is presented in this two-paper set. Part I is mainly devoted to derivation of the theory and algorithm. The objective functions used in the TEP studies take into account investment cost, risk cost and congestion cost. The combination of Monte Carlo simulation (MCS) and Point Estimation Method (PEM) is implemented to investigate the effects of network uncertainties. Due...