scholarly journals Resolving the structure of the Galactic foreground using Herschel measurements and the Kriging technique

2017 ◽  
Vol 12 (S333) ◽  
pp. 168-169
Author(s):  
S. Pinter ◽  
Z. Bagoly ◽  
L. G. Balázs ◽  
I. Horvath ◽  
I. I. Racz ◽  
...  

AbstractInvestigating the distant extragalactic Universe requires a subtraction of the Galactic foreground. One of the major difficulties deriving the fine structure of the galactic foreground is the embedded foreground and background point sources appearing in the given fields. It is especially so in the infrared. We report our study subtracting point sources from Herschel images with Kriging, an interpolation method where the interpolated values are modelled by a Gaussian process governed by prior covariances. Using the Kriging method on Herschel multi-wavelength observations the structure of the Galactic foreground can be studied with much higher resolution than previously, leading to a better foreground subtraction at the end.

2006 ◽  
Vol 2 (S237) ◽  
pp. 482-482 ◽  
Author(s):  
J. S. Urquhart ◽  
A. L. Busfield ◽  
M. G. Hoare ◽  
S. L. Lumsden ◽  
A. J. Clarke ◽  
...  

AbstractThe Red MSX Source (RMS) survey (Hoare et al. 2005) is a multi-wavelength programme of follow-up observations designed to distinguish between genuine massive young stellar objects (MYSOs) and other embedded or dusty objects, such as ultra compact (UC) HII regions, evolved stars and planetary nebulae (PNe). We have identified nearly 2000 MYSOs candidates by comparing the colours of MSX and 2MASS point sources to those of known MYSOs. There are several other types of embedded or dust enshrouded objects that have similar colours as MYSOs and contaminate our sample. Two sources of contamination are from UCHII regions and PNe, both of which can be identified from the radio emission emitted by their ionised nebulae. In order to identify UCHII regions and PNe that contaminate our sample we have conducted high resolution radio continuum observations at 3.6 and 6 cm of all southern MYSOs candidates (235° < l < 350°) using the Australia Telescope Compact Array (ATCA).


2013 ◽  
Vol 444-445 ◽  
pp. 628-632
Author(s):  
Ru Chao Shi ◽  
Sheng Li Xu ◽  
Ya Jun Zhang

This paper presents a 3D numerical simulation of water droplets merging under a given shock wave. We couple interpolation method to RGFM (Real Ghost Fluid Method) to improve the numerical accuracy of RGFM. The flow states of air-water interface are calculated by ARPS (approximate Riemann problem solver). Flow field is solved by Euler equation with fifth-order WENO spatial discretization and fourth-order R-K (Runge-Kutta) time discretization. We also employ fifth-order HJ-WENO to discretize level set equation to keep track of gas-liquid interface. Numerical results demonstrate that droplets shape has little change before merging and the merged droplet gradually becomes umbrella-shaped under the given shock wave. We verify that combination of RGFM with interpolation method has the property of reducing numerical error by comparing to the results without employment of interpolation method.


2012 ◽  
Vol 12 (01) ◽  
pp. 1250006
Author(s):  
SHUHUA LAI ◽  
FUHUA (FRANK) CHENG

A new approach for constructing a smooth subdivision surface to interpolate the vertices of an arbitrary mesh is presented. The construction process does require setting up neither any linear systems, nor any matrix computation, but is simply done by iteratively moving vertices of the given mesh locally until control mesh of the required interpolating surface is reached. The new interpolation method has the simplicity of a local method in effectively dealing with meshes of a large number of vertices. It also has the capability of a global method in faithfully resembling the shape of a given mesh. Furthermore, the new method is fast and does not require a fairing step in the construction process because the iterative process converges to a unique solution at an exponential rate. Another important result of this work is, with the new iterative process, each mesh (surface) can be decomposed into a sum of simpler meshes (surfaces) which carry high-and low-frequency information of the given model. This mesh decomposition scheme provides us with new approaches to some classic applications in computer graphics such as texture mapping, denoising/smoothing/sharpening, and morphing. These new approaches are demonstrated in this paper and test results are included.


2013 ◽  
Vol 34 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Mateusz Moskalik ◽  
Piotr Grabowiecki ◽  
Jarosław Tęgowski ◽  
Monika Żulichowska

Abstract Determination of High Arctic regions bathymetry is strictly dependent from weather and ice mass quantity. Due to safety, it is often necessary to use a small boat to study fjords area, especially close to glaciers with unknown bathymetry. This precludes the use of modern multi−beam echosounders, and so traditional single−beam echosounders have been used for bathymetry profiling. Adequate interpolation techniques were determined for the most probable morphological formations in−between bathymetric profiles. Choosing the most accurate interpolation method allows for the determination of geographical regionalisation of submarine elevations of the Brepollen area (inner part of Hornsund, Spitsbergen). It has also been found that bathymetric interpolations should be performed on averaged grid values, rather than individual records. The Ordinary Kriging Method was identified as the most adequate for interpolations and was compared with multi beam scan− ning, which was possible to make due to a previously modelled single beam interpolation map. In total, eight geographical units were separated in Brepollen, based on the bathy− metry, slope and aspect maps. Presented results provide a truly new image of the area, which allow for further understanding of past and present processes in the High Arctic.


2017 ◽  
Vol 17 (5) ◽  
pp. 53-59
Author(s):  
M.B. Medegey

Linear operators satisfying some conditions are considered. The given operators are a particular kind of class operators (by P.P. Korovkin). For the estimate derivation the interpolation method is used, described in the works by Yu.G. Abakumov and O.N. Shestakova


2014 ◽  
Vol 17 (3) ◽  
pp. 54-61
Author(s):  
Chung Le Thuy Kieu ◽  
Ha Thi San Phan ◽  
Son Minh Le

One of the major tasks in geotechnical investigation is the stratigraphy distribution and the physico-mechanical properties of strata encountered in the investigation area. In order to reduce the project risks associated with uncertainties in predicting the distribution of strata (in area and in depth), a geotechnical investigation plan is usually designed with as many as possible of the boreholes. And this, in turn, increases the investigation costs. On the contrary, the owner of the project is expected to gather as much information about the subsurface soils as possible at the lowest cost. To deal with this contradiction, geotechnical engineers not only mobilize their knowledge on the investigation area and their experiences in the field of geotechnical investigation but also should be supported by geostatistical tools, especially the interpolation method of Kriging. Based on the real data taken from a geotechnical investigation project in Saigon (Vietnam), this paper will introduce two geotechnical investigation plans: a) an actual investigation plan; b) an optimized investigation plan designed with the support of Kriging method. From these two plans, the ability of Kriging in optimization of geotechnical investigation will be evaluated.


2009 ◽  
Vol 505 (2) ◽  
pp. 811-823 ◽  
Author(s):  
S. Berkebile-Stoiser ◽  
P. Gömöry ◽  
A. M. Veronig ◽  
J. Rybák ◽  
P. Sütterlin

2015 ◽  
Vol 4 (1) ◽  
pp. 26
Author(s):  
PUTU MIRAH PURNAMA D. ◽  
KOMANG GDE SUKARSA ◽  
KOMANG DHARMAWAN

Spatial data is data that is presented in the geographic of an object, related to the location, shape and relationship of the earth in space. One of example of spatial data is rainfall. To determine the value of rainfall in an area, built to predict rain post information regarding rainfall. Spatial interpolation is used to estimate rainfall by collecting rainfall values held rain heading around. Assessment methods used in the estimate the rainfall in the Karangasem district is ordinary kriging using isotropic semivariogram that takes into account height on spatial data. Isotropic semivariogram which only takes into account the distance alone. Ordinary kriging method using isotropic semivariogram that takes into account height  value estimated rainfall is much different to the values at the control points Amlapura and Besakih. Interpolation on 3D data are not suitable for use on ordinary kriging method, grouping should be done at the data into a few weeks to application of ordinary kriging interpolation method using anisotropic semivariogram on 3D data.


2019 ◽  
Vol 484 (3) ◽  
pp. 269-272
Author(s):  
V. G. Romanov

For nonmagnetic and nonconductive medium the system of electrodynamic equations that corresponds to periodic in time oscillations is considered. An inverse problem of determining permittivity in this system by the given module of the electric strength is studied. It is supposed that the electric fields is a result of the interference of two fields created by point sources. The permittivity e(x) is assumed to be differ from a given positive constant e0 inside of a compact domain W0 Ì R3 only. An information on module of the electric strength is given on the boundary of the domain W contained W0 inside itself and for all frequencies beginning with some fixed frequency w0. The asymptotic behavior of solution of a direct problem related to the electrodynamic equations is studied and the original inverse problem is reduced to the well known inverse kinematic problem. This reduction open a way for constructive solution of the inverse phaseless problem.


2020 ◽  
Vol 19 (1) ◽  
pp. 43-78 ◽  
Author(s):  
Mikhail Medvedev ◽  
Vladimir Kostjukov ◽  
Viacheslav Pshikhopov

The paper considers the problem of planning a mobile robot movement in a conflict environment, which is characterized by the presence of areas that impede the robot to complete the tasks. The main results of path planning in the conflict environment are considered. Special attention is paid to the approaches based on the risk functions and probabilistic methods. The conflict areas, which are formed by point sources that create in the general case asymmetric fields of a continuous type, are observed. A probabilistic description of such fields is proposed, examples of which are the probability of detection or defeat of a mobile robot. As a field description, the concept of characteristic probability function of the source is introduced; which allows us to optimize the movement of the robot in the conflict environment. The connection between the characteristic probability function of the source and the risk function, which can be used to formulate and solve simplified optimization problems, is demonstrated. The algorithm for mobile robot path planning that ensures the given probability of passing the conflict environment is being developed. An upper bound for the probability of the given environment passing under fixed boundary conditions is obtained. A procedure for optimizing the robot path in the conflict environment is proposed, which is characterized by higher computational efficiency achieved by avoiding the search for an exact optimal solution to a suboptimal one. A procedure is proposed for optimizing the robot path in the conflict environment, which is characterized by higher computational efficiency achieved by avoiding the search for an exact optimal solution to a suboptimal one. The proposed algorithms are implemented in the form of a software simulator for a group of ground-based robots and are studied by numerical simulation methods.


Sign in / Sign up

Export Citation Format

Share Document