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We present a survey of 56 massive star-forming regions in the 44 GHz methanol maser transition made with the Karl G. Jansky Very Large Array (VLA); 24 of the 56 fields showed maser emission. The data allow us to demonstrate associations, at…

Numerical simulations of a complete laser powder bed fusion (LPBF) additive manufacturing (AM) process are extremely challenging or even impossible to achieve without a radical model reduction of the complex physical phenomena occurring…

数值分析 · 数学 2021-12-20 Massimo Carraturo , Alex Viguerie , Alessandro Reali , Ferdinando Auricchio

Let $p$ be a large prime number, $K,L,M,\lambda$ be integers with $1\le M\le p$ and ${\color{red}\gcd}(\lambda,p)=1.$ The aim of our paper is to obtain sharp upper bound estimates for the number $I_2(M; K,L)$ of solutions of the congruence…

数论 · 数学 2010-10-14 J. Cilleruelo , M. Z. Garaev

The Low Mach Number Approximation (LMNA) is applied to 2D hydrodynamical modeling of Type I X-ray bursts on a rectangular patch on the surface of a non-rotating neutron star. Because such phenomena involve decidedly subsonic flows, the…

天体物理学 · 物理学 2008-11-26 David J. Lin , Alvin Bayliss , Ronald E. Taam

The dynamics of collisionless plasmas can be modelled by the Vlasov-Maxwell system of equations. An Eulerian approach is needed to accurately describe processes that are governed by high energy tails in the distribution function, but is of…

等离子体物理 · 物理学 2017-06-29 Benjamin Svedung Wettervik , Timothy Charles DuBois , Evangelos Siminos , Tünde Fülöp

We have conducted multi-epoch EVN observations of the 22.2 GHz water masers towards the high-mass young stellar object in AFGL 5142. With four observing epochs, spanning a time of ~1 year, 12 distinct maser features have been detected, 7…

天体物理学 · 物理学 2009-11-10 C. Goddi , L. Moscadelli , W. Alef , J. Brand

We have observed a sample of 288 molecular outflow sources including 123 high-mass and 165 low-mass sources to search for class I methanol masers at 95 GHz transition and to investigate relationship between outflow characteristics and class…

太阳与恒星天体物理 · 物理学 2015-06-12 Cong-Gui Gan , Xi Chen , Zhi-Qiang Shen , Ye Xu , Bing-Gang Ju

We report on the interferometric detection of 36.2 GHz Class I methanol emission with the new 27-40 GHz Ka band receivers available on the Expanded Very Large Array (EVLA). The brightness temperatures of the interferometric 36 GHz…

星系天体物理 · 物理学 2015-05-18 Lorant O. Sjouwerman , Ylva M. Pihlstrom , Vincent L. Fish

In this paper we present a class of high order accurate cell-centered Arbitrary-Eulerian-Lagrangian (ALE) one-step ADER-WENO finite volume schemes for the solution of nonlinear hyperbolic conservation laws on two-dimensional unstructured…

计算物理 · 物理学 2015-06-17 Walter Boscheri , Michael Dumbser , Dinshaw Balsara

We present a practical numerical method for evaluating the Lagrange multipliers necessary for maintaining a constrained linear geometry of particles in dynamical simulations. The method involves no iterations, and is limited in accuracy…

材料科学 · 物理学 2010-12-16 Horacio Tapia-McClung , Niels Grønbech-Jensen

In modern wireless communication systems, radio propagation modeling to estimate pathloss has always been a fundamental task in system design and optimization. The state-of-the-art empirical propagation models are based on measurements in…

网络与互联网体系结构 · 计算机科学 2022-02-08 Usama Masood , Hasan Farooq , Ali Imran , Adnan Abu-Dayya

We study the weak convergence behaviour of the Leimkuhler--Matthews method, a non-Markovian Euler-type scheme with the same computational cost as the Euler scheme, for the approximation of the stationary distribution of a one-dimensional…

数值分析 · 数学 2025-01-14 Xingyuan Chen , Goncalo dos Reis , Wolfgang Stockinger , Zac Wilde

We tackle the problem of the estimation of the level sets L_f({\lambda}) of the density f of a random vector X supported on a smooth manifold M\subsetR^d , from an iid sample of X. To do that we introduce a kernel-based estimator f^n,h ,…

统计理论 · 数学 2021-03-30 Alejandro Cholaquidis , Ricardo Fraiman , Leonardo Moreno

Identifying low-dimensional structure in high-dimensional probability measures is an essential pre-processing step for efficient sampling. We introduce a method for identifying and approximating a target measure $\pi$ as a perturbation of a…

机器学习 · 统计学 2025-11-19 Matthew T. C. Li , Tiangang Cui , Fengyi Li , Youssef Marzouk , Olivier Zahm

Maximum likelihood (ML) estimation using Newton's method in nonlinear state space models (SSMs) is a challenging problem due to the analytical intractability of the log-likelihood and its gradient and Hessian. We estimate the gradient and…

统计计算 · 统计学 2016-03-11 Manon Kok , Johan Dahlin , Thomas B. Schön , Adrian Wills

A southern hemisphere survey of methanol emission sources has been carried out using the ATNF Mopra millimetre telescope. 85 sources, the majority of them masers, have been detected in the 8(0)-7(1)A+ transition of methanol at 95 GHz.…

天体物理学 · 物理学 2009-10-31 I. E. Val'tts , S. P. Ellingsen , V. I. Slysh , S. V. Kalenskii , R. Otrupcek , G. M. Larinov

Accurate estimation of the internal states of lithium-ion batteries is key towards improving their management for safety, efficiency and longevity purposes. Various approaches exist in the literature in this context, among which designing…

系统与控制 · 电气工程与系统科学 2023-08-21 Mira Khalil , Romain Postoyan , Stéphane Raël

Consideration is given to the three different analytical methods for the computation of upper bounds for the rate of convergence to the limiting regime of one specific class of (in)homogeneous continuous-time Markov chains. This class is…

We present the results of a targeted 3-mm spectral line survey towards the eighty-three 6.67 GHz methanol maser selected star forming clumps observed by Purcell et al. 2006. In addition to the previously reported measurements of HCO+ (1 -…

Context: Methanol masers of Class I (collisionally-pumped) and Class II (radiatively-pumped) have been studied in great detail in our Galaxy in a variety of astrophysical environments such as shocks and star-forming regions and are helpful…