scholarly journals ATHOS: On-the-fly stellar parameter determination of FGK stars based on flux ratios from optical spectra

2018 ◽  
Vol 619 ◽  
pp. A134 ◽  
Author(s):  
Michael Hanke ◽  
Camilla J. Hansen ◽  
Andreas Koch ◽  
Eva K. Grebel

The rapidly increasing number of stellar spectra obtained by existing and future large-scale spectroscopic surveys feeds a demand for fast and efficient tools for the spectroscopic determination of fundamental stellar parameters. Such tools should not only comprise customized solutions for one particular survey or instrument, but, in order to enable cross-survey comparability, they should also be capable of dealing with spectra from a variety of spectrographs, resolutions, and wavelength coverages. To meet these ambitious specifications, we developed ATHOS (A Tool for HOmogenizing Stellar parameters), a fundamentally new analysis tool that adopts easy-to-use, computationally inexpensive analytical relations tying flux ratios (FRs) of designated wavelength regions in optical spectra to the stellar parameters effective temperature (T eff), iron abundance ([Fe/H]), and surface gravity (log g). Our T eff estimator is based on FRs from nine pairs of wavelength ranges around the Balmer lines Hβ and Hα, while for [Fe/H] and log g we provide 31 and 11 FRs, respectively, which are spread between ∼4800 Å and ∼6500 Å; a region covered by most optical surveys. The analytical relations employing these FRs were trained on N = 124 real spectra of a stellar benchmark sample that covers a large parameter space of T eff ≈ 4000–6500 K (spectral types F to K), [Fe/H] ≈ −4.5 to 0.3 dex, and log g ≈ 1–5 dex, which at the same time reflects ATHOS’ range of applicability. We find accuracies of 97 K for T eff, 0.16 dex for [Fe/H], and 0.26 dex for log g, which are merely bounded by finite uncertainties in the training sample parameters. ATHOS’ internal precisions can be better by up to 70%. We tested ATHOS on six independent large surveys spanning a wide range of resolutions (R = λ/Δ λ ≈ 2000–52 000), amongst which are the Gaia-ESO and the SDSS/SEGUE surveys. The exceptionally low execution time (< 30 ms per spectrum per CPU core) together with a comparison to the literature parameters showed that ATHOS can successfully achieve its main objectives, in other words fast stellar parametrization with cross-survey validity, high accuracy, and high precision. These are key to homogenize the output from future surveys, such as 4MOST or WEAVE.

2017 ◽  
Vol 14 (1) ◽  
pp. 257-262
Author(s):  
Chunhui Zhao ◽  
Tingting Dong ◽  
Fang Xu

In order to establish a large sample of the standardization of the norm of the National College Students’ physical exercise behaviour, this study uses the change scale of college students physical exercise behaviour, and a large range of survey of the university students physical exercise behaviour. According to the statistical analysis of the data obtained by the national college students physical exercise behaviour’ change standard norm, it can provide a reliable, effective and valuable reference for the study of college students physical exercise behaviour. In the cross theoretical model, the lack of the determination of the stage of the change, especially after a wide range of survey, produces the precise analysis and interpretation. After a large scale of the investigation, this study not only has a simple region to change the stage and change process, but also to find the corresponding relationship between them, as well as the different stages of the weight of the change process.


1997 ◽  
Vol 129 (S171) ◽  
pp. 69-81 ◽  
Author(s):  
Roy Bateman

AbstractThe use of chemical insecticides, especially as ultra low volume (ULV) formulations, against locusts and grasshoppers will continue for the foreseeable future; therefore application techniques for microbial agents should be as compatible as possible with existing practice. Low volume and ULV spraying of deuteromycete conidia in oil-based formulations have produced very promising acridid control results in the field, although baiting, dusting, and hydraulic application techniques have also been tested for a wide range of pathogens.The key problems for further research and development appear to be the logistics and supply of consistently reliable formulations for application on a large scale, and the determination of mechanisms for effective dose transfer in the field. The application of suspended particulate matter can present special problems with rotary and other atomizers.


2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.


Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.


2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.


Author(s):  
О. Кravchuk ◽  
V. Symonenkov ◽  
I. Symonenkova ◽  
O. Hryhorev

Today, more than forty countries of the world are engaged in the development of military-purpose robots. A number of unique mobile robots with a wide range of capabilities are already being used by combat and intelligence units of the Armed forces of the developed world countries to conduct battlefield intelligence and support tactical groups. At present, the issue of using the latest information technology in the field of military robotics is thoroughly investigated, and the creation of highly effective information management systems in the land-mobile robotic complexes has acquired a new phase associated with the use of distributed information and sensory systems and consists in the transition from application of separate sensors and devices to the construction of modular information subsystems, which provide the availability of various data sources and complex methods of information processing. The purpose of the article is to investigate the ways to increase the autonomy of the land-mobile robotic complexes using in a non-deterministic conditions of modern combat. Relevance of researches is connected with the necessity of creation of highly effective information and control systems in the perspective robotic means for the needs of Land Forces of Ukraine. The development of the Armed Forces of Ukraine management system based on the criteria adopted by the EU and NATO member states is one of the main directions of increasing the effectiveness of the use of forces (forces), which involves achieving the principles and standards necessary for Ukraine to become a member of the EU and NATO. The inherent features of achieving these criteria will be the transition to a reduction of tasks of the combined-arms units and the large-scale use of high-precision weapons and land remote-controlled robotic devices. According to the views of the leading specialists in the field of robotics, the automation of information subsystems and components of the land-mobile robotic complexes can increase safety, reliability, error-tolerance and the effectiveness of the use of robotic means by standardizing the necessary actions with minimal human intervention, that is, a significant increase in the autonomy of the land-mobile robotic complexes for the needs of Land Forces of Ukraine.


2018 ◽  
Vol 68 (12) ◽  
pp. 2857-2859
Author(s):  
Cristina Mihaela Ghiciuc ◽  
Andreea Silvana Szalontay ◽  
Luminita Radulescu ◽  
Sebastian Cozma ◽  
Catalina Elena Lupusoru ◽  
...  

There is an increasing interest in the analysis of salivary biomarkers for medical practice. The objective of this article was to identify the specificity and sensitivity of quantification methods used in biosensors or portable devices for the determination of salivary cortisol and salivary a-amylase. There are no biosensors and portable devices for salivary amylase and cortisol that are used on a large scale in clinical studies. These devices would be useful in assessing more real-time psychological research in the future.


1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.


2012 ◽  
Vol 9 (1) ◽  
pp. 175-180
Author(s):  
Yu.D. Chashechkin

According to the results of visualization of streams, the existence of structures in a wide range of scales is noted: from galactic to micron. The use of a fundamental system of equations is substantiated based on the results of comparing symmetries of various flow models with the usage of theoretical group methods. Complete solutions of the system are found by the methods of the singular perturbations theory with a condition of compatibility, which determines the characteristic equation. A comparison of complete solutions with experimental data shows that regular solutions characterize large-scale components of the flow, a rich family of singular solutions describes formation of the thin media structure. Examples of calculations and observations of stratified, rotating and multiphase media are given. The requirements for the technique of an adequate experiment are discussed.


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