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Interpretation of gravity satellite data to delineate structural features connected to geothermal resources at Bur Ni Geureudong geothermal field

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IOP Conference Series: Earth and Environmental Science 2019年第1期364卷

作者： D R Putri M Nanda S Rizal R Idroes N Ismail Doctoral Program of Mathematics and Applied Science Universitas Syiah Kuala Banda Aceh 23111 Indonesia Marine Sciences Department Universitas Syiah Kuala Banda Aceh 23111 Indonesia Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh 23111 Indonesia Department of Pharmacy Faculty of Mathematics and Natural Sciences Universitas Syiah Kuala Kopelma Darussalam Banda Aceh 23111 Indonesia Department of Physics Faculty of Mathematics and Natural Science Universitas Syiah Kuala Banda Aceh 23111 Indonesia

The gravity method is broadly used in analyzing potential geothermal studies. The method can be used for determining potential areas, reservoir locations, and geological structure investigation. In this paper, satellite gravity data was applied for better understand the geological conditions connected with the geothermal system of Bur Ni Geureudong geothermal field, Bener Meriah District, Aceh, Indonesia. Open access Free Air anomaly data were provided by satellite geodesy information with 1 minute-grid. The data were reduced to obtain Bouguer anomaly distribution in the study area. Tilt derivative (TDR) technique was applied to Bouguer anomaly to enhance linear trends of geological structures. The aim of this analytical technique is able to clearly display faults correlated with geothermal manifestations around the Bur Ni Geureudong geothermal field. The complete Bouguer anomaly range of 20 mGal up to 170 mGal covers Bur Ni Geureudong volcano complex. A low Bouguer anomaly is located in all summits of volcanoes that are included in Bur Ni Geureudong Volcano Complex; those are summits of Bur Geureudong volcano, Bur Ni Telong Volcano, Pepanji Mountain, and Salah Nama Mountain. The low Bouguer anomaly is associated with the andesitic flow and volcanic ashes. The higher Bouguer Anomaly is reflected in high-density basement rock in the west of Geureudong Volcano. Tilt derivative (TDR) shows geological structures more detail, particularly, the tilt derivative (TDR) clearly detects two fault structures over the study area presented by a tilt value of zero. The results will be useful as basic information in exploration study of Bur Ni Geureudong geothermal field.

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Gauges, loops, and polynomials for partition functions of graphical models

arXiv

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arXiv 2018年

作者： Chertkov, Michael Chernyak, Vladimir Maximov, Yury Program in Applied Mathematics University of Arizona TucsonAZ United States CNLS and T-Division LANL Los AlamosNM United States Skolkovo Institute of Technology Moscow Russia Department of Chemistry Wayne State University MI United States

Graphical models (GM) represent multivariate and generally not normalized probability distributions. Computing the normalization factor, called the partition function (PF), is the main inference challenge relevant to multiple statistical and optimization applications. The problem is #P-hard that is of an exponential complexity with respect to the number of variables. In this manuscript, aimed at approximating the PF, we consider Multi-Graph Models (MGMs) where binary variables and multivariable factors are associated with edges and nodes, respectively, of an undirected multigraph. We suggest a new methodology for analysis and computations that combines the Gauge Function (GF) technique from [21, 22] with the technique developed in [34] and [5, 67] based on the recent progress in the field of real stable polynomials. We show that the GF, representing a single-out term in a finite sum expression for the PF which achieves extremum at the so-called Belief-Propagation (BP) gauge, has a natural polynomial representation in terms of gauges/variables associated with edges of the multi-graph. Moreover, GF can be used to recover the PF through a sequence of transformations allowing appealing algebraic and graphical interpretations. Algebraically, one step in the sequence consists in the application of a differential operator over gauges associated with an edge. Graphically, the sequence is interpreted as a repetitive elimination/contraction of edges resulting in MGMs on decreasing in size (number of edges) graphs with the same PF as in the original MGM. Even though the complexity of computing factors in the sequence of derived MGMs and respective GFs grow exponentially with the number of eliminated edges, polynomials associated with the new factors remain bi-stable if the original factors have this property. Moreover, we show that BP estimations in the sequence do not decrease, each low-bounding the PF. Copyright © 2018, The Authors. All rights reserved.

关键词： Graphic methods

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Signatures of many-body localization in steady states of open quantum systems

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Physical Review B 2018年第2期98卷 020202(R)-020202(R)页

作者： I. Vakulchyk I. Yusipov M. Ivanchenko S. Flach S. Denisov Center for Theoretical Physics of Complex Systems IBS Daejeon 34051 Republic of Korea Basic Science Program Korea University of Science and Technology (UST) Daejeon 34113 Republic of Korea Department of Applied Mathematics Lobachevsky University Nizhny Novgorod 603950 Russia Institute of Physics University of Augsburg Universitätsstraße 1 86159 Augsburg Germany

Many-body localization (MBL) is a result of the balance between interference-based Anderson localization and many-body interactions in a high-dimensional Fock space. It is expected that dissipation is blurring interference and destroying that balance so that the asymptotic state of a system with an MBL Hamiltonian does not bear localization signatures. This is evidently true in the case of local dephasing which drives any system into an infinite-temperature state. We demonstrate, by using a set of dissipative operators, where each one is acting nontrivially on a pair of neighboring sites (or spins), that an MBL system can be brought into a Hamiltonian-specific steady state. The difference between ergodic and MBL Hamiltonians can be seen in statistics of imbalance, entanglement entropy, and level spacing of the steady-state density operator. By introducing pairwise dissipative operators into an MBL system already exposed to dephasing, these localization signatures can be restored.

关键词： Many-body localization Open quantum systems

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Estimation of Shear Wave Velocity of Darul Imarah District, Aceh Besar, Indonesia by Using 1D HVSR Inversion

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IOP Conference Series: Materials Science and Engineering 2020年第1期846卷

作者： Y Yusran Aulia Khalqillah Umar Muksin Muhammad Syukri Syamsul Rizal Nazli Ismail Doctoral Program of Mathematics and Applied Sciences Universitas Syiah Kuala Banda Aceh Indonesia Education of Physics Universitas Islam Negeri Ar-Raniry Banda Aceh Indonesia Department of Physics Universitas Syiah Kuala Banda Aceh Indonesia Tsunami and Disaster Mitigation Research Center (TDMRC) Universitas Syiah Kuala Banda Aceh Indonesia Department of Marine Sciences Universitas Syiah Kuala Banda Aceh Indonesia

A total of 19 locations of Horizontal to Vertical Spectral Ratio (HVSR) measurements was conducted in Darul Imarah District, Aceh Besar, Indonesia. The objective of the research is to investigate the shear wave velocity (Vs) structure. This survey is important to analyze a structural characteristic through a Vs, considering the measurement points intersect to Aceh Segment Fault. One of the methods to obtain Vs is 1D HVSR inversion. In this paper, we analyzed only four of 19 measurement points of HVSR data to estimate Vs, they are AB03, AB08, AB09 and AB19 points. The inversion results show that the four points have four layers with different Vs. The average of Vs30 of AB03, AB08, AB09 and AB19 were calculated, they are 150.90 m/s, 197.16 m/s, 150.45 m/s and 316.80 m/s, respectively. The AB09 has the lowest average of Vs30 (highest amplification) than the other points and has soft soil composition. Furthermore, based on the average of Vs30 and amplification, the subsurface of AB03, AB08 and AB19 may have combination soft soil and stiff soil in 30 m depth. The complete analysis of average of Vs30 structure will be conducted at all sites including a 3D velocity structure will be derived from the interpolation of 1D velocity.

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3D ab initio modeling in cryo-em by autocorrelation analysis

arXiv

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arXiv 2017年

作者： Levin, Eitan Bendory, Tamir Boumal, Nicolas Kileel, Joe Singer, Amit Princeton University Program in Applied and Computational Mathematics PrincetonNJ United States

Single-Particle Reconstruction (SPR) in Cryo-Electron Microscopy (cryo-EM) is the task of estimating the 3D structure of a molecule from a set of noisy 2D projections, taken from unknown viewing directions. Many algorithms for SPR start from an initial reference molecule, and alternate between refining the estimated viewing angles given the molecule, and refining the molecule given the viewing angles. This scheme is called iterative refinement. Reliance on an initial, user-chosen reference introduces model bias, and poor initialization can lead to slow convergence. Furthermore, since no ground truth is available for an unsolved molecule, it is difficult to validate the obtained results. This creates the need for high quality ab initio models that can be quickly obtained from experimental data with minimal priors, and which can also be used for validation. We propose a procedure to obtain such an ab initio model directly from raw data using Kam's autocorrelation method. Kam's method has been known since 1980, but it leads to an underdetermined system, with missing orthogonal matrices. Until now, this system has been solved only for special cases, such as highly symmetric molecules or molecules for which a homologous structure was already available. In this paper, we show that knowledge of just two clean projections is sufficient to guarantee a unique solution to the system. This system is solved by an optimization-based heuristic. For the first time, we are then able to obtain a low-resolution ab initio model of an asymmetric molecule directly from raw data, without 2D class averaging and without tilting. Numerical results are presented on both synthetic and experimental data. Copyright © 2017, The Authors. All rights reserved.

关键词： Molecules

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Luminescence properties and Judd-Ofelt analysis of Sm 3+ doped lithium aluminium phosphate glasses

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Materials Today: Proceedings 2018年第7期5卷 15034-15039页

作者： N. Chanthima Y. Tariwong M. Djamal J. Kaewkhao N.W. Sangwaranatee N. Sangwaranatee Center of Excellence in Glass Technology and Materials Science (CEGM) Nakhon Pathom Rajabhat University Nakhon Pathom 73000 Thailand Physics Program Faculty of Science and Technology Nakhon Pathom Rajabhat University Nakhon Pathom 73000 Thailand Department of Physics Faculty of Mathematics and Natural Sciences Institut Teknologi Bandung 40132 Indonesia Informatics Mathematics Faculty of Science and Technology Suan Sunandha Rajabhat University Bangkok 10300 Thailand Applied Physics Faculty of Science and Technology Suan Sunandha Rajabhat University Bangkok 10300 Thailand

Lithium aluminium phosphate glasses doped with samarium oxide were prepared by melt-quenching technique and investigated their physical, optical and luminescence properties. The result of physical properties indicated that the density and the molar volume of glass samples were increased with an increase of Sm 2 O 3 content. The absorption spectra of glass samples were recorded in the wavelength range of 250-2000 nm, these glasses have shown strong absorption bands in the visible (Vis) and near-infrared (NIR) region at 401 and 1232 nm. The emission spectra of glasses, excited with 401 nm excitation wavelength showed four emission bands centered at 561, 597, 644 and 704 nm. From Judd-Ofelt analysis, the J-O parameter (Ω 2 , Ω 4 , Ω 6 ), radiative transition possibility ( A R ), stimulated emission cross-section (σ(λ p )) and branching ratios ( β R ) were indicated that the glass samples an interesting potential for using glass as laser medium with 597 nm emitting.

关键词： Judd-Ofelt analysis Luminescence Phosphate glass Samarium ion

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Partial deconfinement at strong coupling on the lattice

arXiv

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arXiv 2020年

作者： Watanabe, Hiromasa Bergner, Georg Bodendorfer, Norbert Funai, Shotaro Shiba Hanada, Masanori Rinaldi, Enrico Schäfer, Andreas Vranas, Pavlos Graduate School of Pure and Applied Sciences University of Tsukuba Tsukuba Ibaraki305-8571 Japan University of Jena Institute for Theoretical Physics Max-Wien-Platz 1 JenaD-07743 Germany University of Regensburg Institute of Theoretical Physics Universitätsstrasse 31 D-93053 Germany 1919-1 Tancha Onna-son Kunigami-gun Okinawa904-0495 Japan Department of Mathematics University of Surrey Guildford SurreyGU2 7XH United Kingdom Arithmer Inc. R&D Headquarters Minato Tokyo106-6040 Japan RIKEN iTHEMS Program Wako Saitama351-0198 Japan Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory LivermoreCA94550 United States Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States

We provide evidence for partial deconfinement - the deconfinement of a SU(M) subgroup of the SU(N) gauge group - by using lattice Monte Carlo simulations. We take matrix models as concrete examples. By appropriately fixing the gauge, we observe that the M×M submatrices deconfine. This gives direct evidence for partial deconfinement at strong coupling. We discuss the applications to QCD and holography. Copyright © 2020, The Authors. All rights reserved.

关键词： Monte Carlo methods

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Phase space homogenization of noisy hamil-tonian systems

arXiv

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arXiv 2017年

作者： Birrell, Jeremiah Wehr, Jan Department of Mathematics University of Arizona TucsonAZ85721 United States Department of Mathematics and Program in Applied Mathematics University of Arizona TucsonAZ85721 United States

We study the dynamics of an inertial particle coupled to forcing, dissipation, and noise in the small mass limit. We derive an expression for the limiting (homogenized) joint distribution of the position and (scaled) velocity degrees of freedom. In particular, weak convergence of the joint distributions is established, along with a bound on the convergence rate for a wide class of expected *** Codes 60H10, 82C31 Copyright © 2017, The Authors. All rights reserved.

关键词： Differential equations

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A homogenization theorem for langevin systems with an application to hamiltonian dynamics

arXiv

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arXiv 2017年

This paper studies homogenization of stochastic differential systems. The standard example of this phenomenon is the small mass limit of Hamiltonian *** consider this case first from the heuristic point of view, stressing the role of detailed balance and presenting the heuristics based on a multiscale expansion. This is used to propose a physical interpretation of recent results by the authors, as well as to motivate a new theorem proven here. Its main content is a sufficient condition, expressed in terms of solvability of an associated partial differential equation ("the cell problem"), under which the homogenization limit of an SDE is calculated explicitly. The general theorem is applied to a class of systems, satisfying a generalized detailed balance condition with a position-dependent temperature. Copyright © 2017, The Authors. All rights reserved.

关键词： Stochastic systems

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High temperature structure detection in ferromagnets

arXiv

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arXiv 2018年

作者： Cao, Yuan Neykov, Matey Liu, Han Program in Applied and Computational Mathematics Princeton University PrincetonNJ United States Department of Statistics & Data Science Carnegie Mellon University PittsburghPA United States Department of Electrical Engineering and Computer Science Northwestern University EvanstonIL United States

This paper studies structure detection problems in high temperature ferromagnetic (positive interaction only) Ising models. The goal is to distinguish whether the underlying graph is empty, i.e., the model consists of independent Rademacher variables, versus the alternative that the underlying graph contains a subgraph of a certain structure. We give matching upper and lower minimax bounds under which testing this problem is possible/impossible respectively. Our results reveal that a key quantity called graph arboricity drives the testability of the problem. On the computational front, under a conjecture of the computational hardness of sparse principal component analysis, we prove that, unless the signal is strong enough, there are no polynomial time linear tests on the sample covariance matrix which are capable of testing this problem. Copyright © 2018, The Authors. All rights reserved.

关键词： Ferromagnetism

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