Sharif Digital Repository

We investigate the problem of communicating three parameters in the absence of shared reference frame. We explore two methods in which the relative angles of spins are used to encode the parameters. In the first method we use three spins that carry the information in their relative angles while in the second method we use three disjoint spin-pairs and the information is sent through the relative angles of each individual pair. We show that in the first method, the information conveyed by each qubit is more than the second one, and that is while it requires fewer particles. © 2021 Elsevier B.V  

In recent years, the emission of various pollutants has caused many problems for human life and the ecosystem. The prioritization between different air pollution control scenarios is a challenge between scientists and policy-makers. This study develops an integrated method for sustainable energy planning considering the energy-pollution-health nexus. The paper investigates three main pollutants (i.e., PM2.5, SO2, and NOx) of different emission sources (i.e., industrial, residential, and intra-city and suburban transportations) in twelve scenarios. The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is applied to model the air pollution dispersion,... 

Consumption of fossil fuels in residential, industrial, and transportation sectors has a significant contribution to air pollution and high attributable premature deaths. To target specific strategies for reducing health effects, the anthropogenic sources and their contributions should be identified. This article provides an integrated modeling approach to evaluate the sector-specific contributions of different PM2.5 sources on air pollution and relevant health impacts. The dispersion of emissions from different sources is modeled by the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD), and the health impacts are estimated by the Environmental... 

We show that a shared singlet state (SSS) can supersede a shared reference frame (SRF) in certain quantum communication tasks, i.e., tasks in which two remote players are required to estimate certain parameters of a two-particle state sent to them. This shows that task-specific values of resources may be somewhat different from their common values based on their exchange possibilities. © 2019 American Physical Society. ©2019 American Physical Society  

We show that two parties far apart can use shared entangled states and classical communication to align their coordinate systems with a very high fidelity. Moreover, compared with previous methods proposed for such a task, i.e., sending parallel or antiparallel pairs or groups of spin states, our method has the extra advantages of using single-qubit measurements and also being secure, so that third parties do not extract any information about the aligned coordinate system established between the two parties. The latter property is important in many other quantum information protocols in which measurements inevitably play a significant role. © 2017 American Physical Society  

Any quantum communication task requires a common reference frame (i.e., phase, coordinate system). In particular, quantum key distribution requires different bases for preparation and measurements of states which are obviously based on the existence of a common frame of reference. Here, we show how QKD can be achieved in the absence of any common frame of reference. We study the coordinate reference frame, where the two parties do not even share a single direction, but the method can be generalized to other general frames of reference, pertaining to other groups of transformations. © 2019, Springer Science+Business Media, LLC, part of Springer Nature  

It is beyond dispute that technological change acts as a driver of economic growth. In developing countries where highly suffer from lack of this process, incremental innovation is considered as main source of technology capability building and development In moving toward this pass and to meet with time pressure of catching up, developing countries acquire the initial required knowledge base through technology absorption from outside sources; On the other hand as development is a lengthy process, it is important that the absorbed knowledge still has the potential of more advancement in future. Therefore a selection instrument with ability of assessing different knowledge base or... 

This paper presents a powerful application of genetic algorithm (GA) for the minimization of the total harmonic current distortion (THCD) in high-power induction motors fed by voltage source inverters, based on an approximate harmonic model. That is, having defined a desired fundamental output voltage, optimal pulse patterns (switching angles) are determined to produce the fundamental output voltage while minimizing the THCD. The complete results for the two cases of three and five switching instants in the first quarter period of pulse width modulation (PWM) waveform are presented. Presence of harmonics in the stator excitation leads to a pulsing-torque component. Considering the fact that... 

We investigate the average frequency of positive slope ν +α, crossing the velocity field in the Burgers equation. The level crossing analysis in the inviscid limit and the total number of positive crossings of the velocity field before the creation of singularities are given. The main goal of this paper is to show that this quantity, ν+α, is a good measure for the fluctuations of velocity fields in the Burgers turbulence. © 2006 IOP Publishing Ltd  

The purpose of this work is to decrease coupling effects of a tactical missile by designing a robust autopilot for its roll channel. In tactical STT missiles due to control strategy, in order to execute acceleration commands, roll angular velocity should be kept close to zero. Generally, in the design of autopilot for many of tactical missiles the inter influences of channels is neglected. However, three channels of the missile impact each other in different ways including kinematic, inertia and aerodynamic couplings. Aerodynamic coupling is a dominant in roll channel dynamics appearing as induced and control cross coupling roll moments. In this paper first the coupling terms are modeled... 

In this article we have acquired exact solitary wave solutions for the truncated Ω- fractional Lakshamanan–Porsezian–Daniel model with Kerr, parabolic, and anti-cubic nonlinear laws employing extended auxiliary technique. Diverse set of exponential function solutions acquired relying on a map between the considered equation and an auxiliary ODE. Obtained solutions are recast in several hyperbolic and trigonometric forms based on different restrictions between parameters involved in equations and integration constants that appear in the solution. A few significant ones among the reported solutions are pictured to perceive the physical utility and peculiarity of the considered model using... 

In recent years, IWR (Isolated Word Recognition) was one of the main concerns of speech processing. The challenging problems in this field appear when the database become so large or when we have a lot of word with similarly pronounce in the database. This paper introduces a general solution for a traditional problem in isolated similarly pronounced word recognition, especially in large databases. One the important problem of traditional IWR is referred to their segmentation algorithm, their methods were lacking in efficiency due to the following reasons: First, using equal segmentation is not at all intelligent at all and as a result, cannot produce accurate results; besides, utilizing... 

Unwanted vibrations of vehicles are regarded as harmful threats to human health in biomechanical and psychophysical terms. Road roughness is considered as the main cause of unwanted vibrations of bus vehicles. Vertical seat vibrations were found via simulating a 10-Degree-Of-Freedom (10-DOF) model of an intercity bus vehicle under harmonic and random excitations caused by road roughness. To suppress undesirable vibrations, mass-spring-damper passive absorbers were proposed in a 13-Degree-Of- Freedom (13-DOF) model of the bus. Following the optimization of the characteristics of embedded passive absorbers under each seat and implementation of the designed absorbers, the vertical displacement... 

In this research, titanium dioxide (TiO2) ultra-thin films have been successfully obtained on lamina-glass substrates by thermal oxidation of DC magnetron sputtered titanium. The as-deposited and the annealed films have been characterized by different techniques. The X-ray diffraction (XRD) results revealed the amorphous structure of as-deposited titanium and anatase crystal structure for the annealed films. The atomic force microscopy (AFM) results showed that increasing the annealing temperature could lead to rougher and larger grain size in the films. Finally, the optical data and band-gap calculations of the films were obtained using the transmittance spectrum, indicating that... 

Small Permanent Magnet Synchronous Generators (PMSG's) are widely used in low power wind turbines. In order to inject the electrical power, generated by PMSG, to the grid, a back-To-back AC/AC power electronic converter is required. In this paper, a novel low cost efficient AC/DC converter is proposed for rectifier stage to obtain the maximum power per ampere of PMSG by using Power Factor Correction method. The new structure is based on DCM SEPIC converter. Reducing the number of semi-conductor switches has decreased converter cost. Additionally, other advantages of this Converter are employing easy control method to obtain the maximum power per ampere and using Synchronous inductance of... 

Purpose: The main purpose of this study is to review the knowledge management literature from a content-related perspective using cluster analysis. Design/methodology/approach: A critical analysis of previous review articles in KM provided a conceptual framework with nine dimensions. A survey was then administered to 120 KM authors asking them to review which dimensions they considered in their own research. Findings: Three clusters of KM research were identified as follows: the socialization school, the collaboration school, and the codification school. Research limitations/implications: The study does not consider the dimension of strategic versus operational KM issues nor does it consider... 

Based on the code specifications, in moment-resisting frames the span-to-depth ratio has to be larger than a minimum value to make sure of adequate plastic hinging at beam-ends. This provision poses a restriction on the use of deep beams with short spans, especially for the framed-tube system in tall buildings. In this paper, a new energy dissipation method is introduced for moment-resisting frames by modifying the mid-span of the beam by two different methods, resulting in: (i) Perforated Shear Links (PSLs) and (ii) Slit Shear Links (SSLs). The links dissipate energy through shear yielding of the web, weakened by perforation or slitting, respectively. A thorough study is conducted on the...