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A relativistic approach to nonlinear peculiar


 We study the peculiar motion of non-relativisticmatter in a fully covariant way. The exact nonlinear equations are derived and then applied to the case of pressure-free matter, moving relatively to a quasi-Newtonian Eulerian frame. Our two-frame formalism facilitates the study of the nonlinear kinematics of the matter, as the latter decouples from the background expansion and starts to “turn around” and collapse. Applied to second perturbative order,our equations provide a fully covariant formulation of the Zeldovich approximation, whichby construction addresses the mildly nonlinear regime of structure formation. Employing a dynamical system approach, we show that, just like in the Newtonian case, the

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On the perturbation of the luminosity distance by peculiar motions


We consider some aspects of the perturbation to the luminosity distance d(z) thatare of relevance for SN1a cosmology and for future peculiar velocity surveys at non-negligible redshifts.1) Previous work has shown that the correction to the lowest order perturba-tion d/d = −v/cz has the peculiar characteristic that it appears to depend on theabsolute state of motion of sources, rather than on their motion relative to that ofthe observer. The resolution of this apparent violation of the equivalence principle isthat it is necessary to allow for evolution of the velocities with time, and also, whenconsidering perturbations on the scale of the observer-source separation, to includethe gravitational red

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Correlated Fluctuations in Luminosity Distance and the Importance of Peculiar Motion in Supernova Surveys


Large scale structure introduces two different kinds of errors in the luminosity distance estimatesfrom standardizable candles such as supernovae Ia (SNe) – a Poissonian scatter for each SN and acoherent component due to correlated fluctuations between different SNe. Increasing the number ofSNe helps reduce the first type of error but not the second. The coherent component has been largelyignored in forecasts of dark energy parameter estimation from upcoming SN surveys. For instanceit is commonly thought, based on Poissonian considerations, that peculiar motion is unimportant,even for a low redshift SN survey such as the Nearby Supernova Factory (SNfactory; z

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THE PECULIAR VELOCITIES OF LOCAL TYPE Ia SUPERNOVAE AND THEIR IMPACT ON COSMOLOGY


 We quantify the effect of supernova Type Ia peculiar velocities on the derivation of cosmological parameters. The published distant and local Ia SNe used for the Supernova Legacy Survey first-year cosmology report form the sample for this study. While previous work has assumed that the local SNe are at rest in the CMB frame (the No Flow assumption), we test this assumption by applying peculiar velocity corrections to the local SNe using three different flow models. The models are based on the IRAS PSCz galaxy redshift survey, have varying = 0.6m /b, and reproduce the Local Group motionin the CMB frame. These datasets are then fit for w, m, and using flatne

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جنبه های انتقادی روش های تجربی تشخیص آسیب دیدگی با استفاده از ارتعاشات اولتراسونیک غیر خطی


          عنوان انگلیسی: Critical aspects of experimental damage detection methodologiesusing nonlinear vibro-ultrasonics عنوان فارسی: جنبه های انتقادی روش های تجربی تشخیص آسیب دیدگی با استفاده از ارتعاشات اولتراسونیک غیر خطی  رشته :صنایع، مکانیک ، عمرانتعداد صفحات مقاله اصلی: 8صفحه (pdf)تعداد صفحات ترجمه:20صفحه (word)سال انتشار:2017 مجله Procedia Engineering   188  ( 2017 )  133 – 140       Abstract:Nonlinear ultrasonics has become a major research focus in non-destructive testing (NDT) in recent years. Techniques using higher harmonics or

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کتاب حل تحلیلی معادلات نوسانگرهای غیرخطی Strong Nonlinear Oscillators : Analytical Solutions


کتاب حل تحلیلی معادلات نوسانگرهای به شدت غیرخطی، تالیف Cveticanin, Livija، چاپ دوم، سال چاپ: 2018، انتشارات Springerنام لاتین کتاب: Strong Nonlinear Oscillators : Analytical Solutions, by: Livija Cveticanin, 2nd Edition, 2018.در این کتاب تمرینهای زیادی  برای حل تحلیلی دقیق معادلات دیفرانسیل مرتبه دوم با اردرهای غیرخطی متنوع بصورت تشریحی پاسخ داده شده است. مناسب برای رشته های برق و مکانیک برای حل مسائل غیرخطی مثل درس  ارتعاشات غیر خطی است. این کتاب شامل 320 صفحه و با سرفصل های زیر است:1)  Introduction 2)  Nonlinear Oscillators 3)  Pure Nonlinear Oscillator 4)  Free Vibrations 5)  Oscillators with the Time Variable Parameters 6)&

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Measuring our peculiar velocity on the CMB with high-multipole


Our peculiar velocity with respect to the CMB rest frame is known to induce a large dipole inthe CMB. However, the motion of an observer has also the effect of distorting the anisotropies atall scales, as shown by Challinor and Van Leeuwen (2002), due to aberration and Doppler effects.We propose to measure independently our local motion by using off-diagonal two-point correlationfunctions for high multipoles. We study the observability of the signal for temperature and polarizationanisotropies. We point out that Planck can measure the velocity with an error of about30% and the direction with an error of about 20. This method constitutes a cross-check, which canbe useful to verify that our CMB dipole is due

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اصل و ترجمه مقاله لاتین Seismic Performance Evaluation of Urban Bridge using Static Nonlinear Procedure, Case Study: Hafez Bridge


Seismic Performance Evaluation of Urban Bridge using Static Nonlinear Procedure, Case Study: Hafez BridgeAbstractBridges as key elements in the lifeline of each country or urban transportation play a fundamental role economically, politically and militarily. The possibility of severe damage to bridges that are subjected to earthquake leads to the necessity of seismic evaluation of existing bridges, particularly those which have been either designed regardless of earthquake effects or according to moderate earthquake-resistant consideration. The assessment of safety and stability of these bridges while passing increasingly traffic is of

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ترجمه مقاله مبحث تدارک منابع در رایانش ابری با عنوان A benefit-aware on-demand provisioning approach for multi-tier applications in cloud computing


ترجمه مقاله ای با مبحث تدارک منابع در رایانش ابری با عنوانA benefit-aware on-demand provisioning approach for multi-tier applications in cloud computingعنوان فارسی مقاله:یک روش تدارک منابع به شکلی آگاه از مزیت و مبتنی بر تقاضا، برای برنامه‌های کاربردی چند لایه‌ای در رایانش ابریچکیده فارسی:تدارک منبع به شکلی پویا را می‌توان تکنیکی چالش‌برانگیز برای پاسخ به نیازمندی‌های توافق در سطح سرویس (SLA)   و آن‌هم برای برنامه‌های کاربردی چندلایه‌ای در محیط رایانش ابری مبتنی بر مجازی‌سازی دانست. فعالیت‌هایی که قبلاً به بررسی و حل‌وفصل این چالش پرداخته‌اند، بر مبنای یک

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اصل و ترجمه مقاله لاتین All-Optical Ultra compact Photonic Crystal Switch Based on Nonlinear Micro Ring Resonators


All-Optical Ultra compact Photonic Crystal Switch Based on Nonlinear Micro Ring ResonatorsABSTRACT:In this paper an all-optical switch has been proposed based on photonic crystal T-type ring resonator. The finite different time domain (FDTD) and plane wave extended (PWE) methods are used to analyze the behavior of the structure. The T-type ring resonator has a low switching time of about 0.95ps and low switching power equal to 156mW/μm2. Since the structure has a simple geometric shape with clear operating principle, it is potentially applicable for photonic integratedcircuits.Keywords: nonlinear Kerr effect, photonic crystal, ring resonator, switch.&nb

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