scholarly journals Chromospheric activity of 9 Aurigae

2013 ◽  
Vol 9 (S301) ◽  
pp. 439-440
Author(s):  
Anthony B. Kaye ◽  
Cristine Kristof ◽  
Richard O. Gray
Keyword(s):  
Magnetic Fields ◽  
Variable Stars ◽  
Blue Edge ◽  
New Class ◽  
Chromospheric Activity ◽  
Definition Of

AbstractThe definition of γ Dor stars as a new class of variable stars by Kaye et al. (1999) was based on a number of criteria, including the failure to detect any emission in the Ca II H & K lines in these stars (Kaye & Strassmeier 1998; KS98). Over the last 30 years, efforts continue to look for the blue edge of chromospheric activity. As a part of this effort, we put γ Dor stars to the test to see if magnetic fields play a non-trivial role in their variability.

scholarly journals Some Inequalities for LR-$$\left({h}_{1}, {h}_{2}\right)$$-Convex Interval-Valued Functions by Means of Pseudo Order Relation

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Muhammad Bilal Khan ◽  
Muhammad Aslam Noor ◽  
Khalida Inayat Noor ◽  
Kottakkaran Sooppy Nisar ◽  
Khadiga Ahmed Ismail ◽  
...  
Keyword(s):  
Applied Mathematics ◽  
Critical Role ◽  
Order Relation ◽  
Strong Relationship ◽  
New Class ◽  
Starting Point ◽  
Interval Valued Function ◽  
Fejér Inequality ◽  
Definition Of ◽  
Interval Valued

AbstractIn both theoretical and applied mathematics fields, integral inequalities play a critical role. Due to the behavior of the definition of convexity, both concepts convexity and integral inequality depend on each other. Therefore, the relationship between convexity and symmetry is strong. Whichever one we work on, we introduced the new class of generalized convex function is known as LR-$$\left({h}_{1}, {h}_{2}\right)$$ h 1 , h 2 -convex interval-valued function (LR-$$\left({h}_{1}, {h}_{2}\right)$$ h 1 , h 2 -IVF) by means of pseudo order relation. Then, we established its strong relationship between Hermite–Hadamard inequality (HH-inequality)) and their variant forms. Besides, we derive the Hermite–Hadamard–Fejér inequality (HH–Fejér inequality)) for LR-$$\left({h}_{1}, {h}_{2}\right)$$ h 1 , h 2 -convex interval-valued functions. Several exceptional cases are also obtained which can be viewed as its applications of this new concept of convexity. Useful examples are given that verify the validity of the theory established in this research. This paper’s concepts and techniques may be the starting point for further research in this field.

scholarly journals Towards a Theory for Unintended Consequences in Engineering Design

2019 ◽  
Vol 1 (1) ◽  
pp. 3411-3420
Author(s):  
Hannah Walsh ◽  
Andy Dong ◽  
Irem Tumer
Keyword(s):  
Failure Analysis ◽  
Engineering Design ◽  
Bifurcation Analysis ◽  
Real World ◽  
Unintended Consequences ◽  
Novel Technologies ◽  
New Class ◽  
Failure State ◽  
Engineered Systems ◽  
Definition Of

AbstractConventional failure analysis ignores a growing challenge in the responsible implementation of novel technologies into engineered systems - unintended consequences, which impact the engineered system itself and other systems including social and environmental systems. In this paper, a theory for unintended consequences is developed. The paper proposes a new definition of unintended consequences as behaviors that are not intentionally designed-into an engineered system yet occur even when a system is operating nominally, that is, not in a failure state as conventionally understood. It is argued that the primary cause for this difference is the bounded rationality of human designers. The formation of unintended consequences is modeled with system dynamics, using a specific real-world example, and bifurcation analysis. The paper develops propositions to guide research in the development of new design methods that could mitigate or control the occurrence and impact of unintended consequences. The end goal of the research is to create a new class of failure analysis tools to manage unintended consequences responsibly to facilitate engineering design for a more sustainable future.

Centroidal frames in dynamical systems I. Point vortices

1992 ◽  
Vol 439 (1907) ◽  
pp. 441-463 ◽  
Keyword(s):  
Point Vortices ◽  
Centre Of Mass ◽  
Permutation Symmetry ◽  
Chaotic Motions ◽  
Small Perturbations ◽  
New Class ◽  
Angular Velocities ◽  
Mass Frame ◽  
Definition Of ◽  
Asymptotic Symmetries

The dynamics of point vortices is studied in Part I of the paper. It is well known that the (translational) centre-of-mass frame decomposes the motion of a mechanical system into simpler components. It is less known, however, that special rotational frames have also been suggested for the same purpose. In contrast to the centre-of-mass frame, the angular velocities of these rotational frames are not given explicitly that limits their application to small perturbations of rigid body rotations. A new class of centroidal frames (CF) related to different groups such as translation, rotation, dilation, etc., is introduced in this paper. The CFS decompose the motion of point vortices into a group and a relative components without restriction to small perturbations of pure group motions. The definition of the CFS is based on an averaging of motion or on minimization of energy of the relative motion, where an appropriate energy function is expressed through generators of the group action. As a result, the linear and angular velocities as well as other characteristics of the CFS can be obtained explicitly. Part I of the paper presents application of the CFS to a hamiltonian system of point vortices. Examples of integrable and chaotic motions in the CFS visualize dynamical patterns that are completely hidden in the conventional fixed frame (ff). Motions which look like chaotic in the FF reveal a variety of stable and unstable structures in the CFS. Quasi-periodic and chaotic motions coexist for all energies and the CFS permit to clearly distinguish between them. A new phenomenon of asymptotic symmetries (in rotational CFS) of some chaotic motions is discovered. This is related to a permutation symmetry of the hamiltonian.

scholarly journals Inhomogeneous spatial point processes by location-dependent scaling

2003 ◽  
Vol 35 (02) ◽  
pp. 319-336 ◽  
Author(s):  
Ute Hahn ◽  
Eva B. Vedel Jensen ◽  
Marie-Colette van Lieshout ◽  
Linda Stougaard Nielsen
Keyword(s):  
Point Processes ◽  
Spatial Point Processes ◽  
New Approach ◽  
Local Scaling ◽  
New Class ◽  
Spatial Point ◽  
New Process ◽  
Markov Point Processes ◽  
Global Scaling ◽  
Definition Of

A new class of models for inhomogeneous spatial point processes is introduced. These locally scaled point processes are modifications of homogeneous template point processes, having the property that regions with different intensities differ only by a scale factor. This is achieved by replacing volume measures used in the density with locally scaled analogues defined by a location-dependent scaling function. The new approach is particularly appealing for modelling inhomogeneous Markov point processes. Distance-interaction and shot noise weighted Markov point processes are discussed in detail. It is shown that the locally scaled versions are again Markov and that locally the Papangelou conditional intensity of the new process behaves like that of a global scaling of the homogeneous process. Approximations are suggested that simplify calculation of the density, for example, in simulation. For sequential point processes, an alternative and simpler definition of local scaling is proposed.

Chromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey

New Astronomy ◽  
2018 ◽  
Vol 61 ◽  
pp. 36-58 ◽  
Author(s):  
Liyun Zhang ◽  
Hongpeng Lu ◽  
Xianming L. Han ◽  
Linyan Jiang ◽  
Zhongmu Li ◽  
...  
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Chromospheric Activity ◽  
Spectral Survey

scholarly journals Topology of Coronal Magnetic Fields: Extending the Magnetic Skeleton Using Null-like Points

Solar Physics ◽  
2020 ◽  
Vol 295 (12) ◽  
Author(s):  
Daniel T. Lee ◽  
Daniel S. Brown
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Free Field ◽  
Point Sources ◽  
Topological Features ◽  
Perpendicular Component ◽  
Definition Of ◽  
Magnetic Null ◽  
The Magnetic Field ◽  
Continuous Source

AbstractMany phenomena in the Sun’s atmosphere are magnetic in nature and study of the atmospheric magnetic field plays an important part in understanding these phenomena. Tools to study solar magnetic fields include magnetic topology and features such as magnetic null points, separatrix surfaces, and separators. The theory of these has most robustly been developed under magnetic charge topology, where the sources of the magnetic field are taken to be discrete, but observed magnetic fields are continuously distributed, and reconstructions and numerical simulations typically use continuously distributed magnetic boundary conditions. This article investigates the pitfalls in using continuous-source descriptions, particularly when null points on the $z=0$ z = 0 plane are obscured by the continuous flux distribution through, e.g., the overlap of non-point sources. The idea of null-like points on the boundary is introduced where the parallel requirement on the field $B_{\parallel }=0$ B ∥ = 0 is retained but the requirement on the perpendicular component is relaxed, i.e. $B_{\perp }\ne 0$ B ⊥ ≠ 0 . These allow the definition of separatrix-like surfaces which are shown (through use of a squashing factor) to be a class of quasi-separatrix layer, and separator-like lines which retain the x-line structure of separators. Examples are given that demonstrate that the use of null-like points can reinstate topological features that are eliminated in the transition from discrete to continuous sources, and that their inclusion in more involved cases can enhance understanding of the magnetic structure and even change the resulting conclusions. While the examples in this article use the potential approximation, the definition of null-like points is more general and may be employed in other cases such as force-free field extrapolations and MHD simulations.

scholarly journals The Secret Lives of Cepheids:δCep—The Prototype of a New Class of Pulsating X-Ray Variable Stars*

2017 ◽  
Vol 838 (1) ◽  
pp. 67 ◽  
Author(s):  
Scott G. Engle ◽  
Edward F. Guinan ◽  
Graham M. Harper ◽  
Manfred Cuntz ◽  
Nancy Remage Evans ◽  
...  
Keyword(s):  
Variable Stars ◽  
X Ray ◽  
New Class

scholarly journals Division V: Variable Stars

2005 ◽  
Vol 1 (T26A) ◽  
pp. 245-245
Author(s):  
Jørgen Christensen-Dalsgaard ◽  
Conny Aerts ◽  
Alvaro Giménez ◽  
Edward F. Guinan ◽  
Luis A. Balona ◽  
...  
Keyword(s):  
Variable Stars ◽  
High Order ◽  
Close Binaries ◽  
Intrinsic Variability ◽  
Definition Of

Division V, “Variable Stars”, consists of Commission 27, also called “Variable Stars” and Commission 42, “Close Binaries”. Thus the former deals with stars whose variations are intrinsic, whereas in the latter the variations are caused by the interactions between the components in the binary. It is evident that the definition of the Division is predominantly observational, and there may be cases where the assignment of an object to one of the two commissions might be in doubt (a recent somewhat related example was the first detection of an extra-solar planet, in 54 Pegasi, where intrinsic variability of the star in the form of high-order g modes was also initially suspected).

What Are Virtual Manipulatives?

2002 ◽  
Vol 8 (6) ◽  
pp. 372-377
Author(s):  
Patricia S. Moyer ◽  
Johnna J. Bolyard ◽  
Mark A. Spikell
Keyword(s):  
Teaching And Learning ◽  
Virtual Manipulatives ◽  
The Internet ◽  
New Approach ◽  
New Class ◽  
Working Definition ◽  
Teaching And Learning Mathematics ◽  
Learning Mathematics ◽  
Definition Of ◽  
Classroom Use

As a result of innovations in technology, the prevalence of the Internet, and the increasing availability of computers in classrooms and homes, an enhanced approach for teaching and learning mathematics using manipulatives and computers is emerging. This new approach essentially creates a new class of manipulatives, called virtual manipulatives, as well as new capabilities, or toolkits, for computer programs that use visual representations. These new virtual manipulatives have all the useful properties of existing computer manipulatives while overcoming many of their disadvantages, yet very little is known or written about them. The purpose of this article is to establish a working definition of virtual manipulatives, highlight examples of virtual manipulatives on the Internet, and discuss their current and potential classroom use.

scholarly journals Enviromics in breeding: applications and perspectives on envirotypic-assisted selection

2019 ◽  
Author(s):  
Rafael T. Resende ◽  
Hans-Peter Piepho ◽  
Orzenil B. Silva-Junior ◽  
Fabyano F. e Silva ◽  
Marcos Deon V. de Resende ◽  
...  
Keyword(s):  
Genotype By Environment Interaction ◽  
Environment Interaction ◽  
New Class ◽  
Strategic Plans ◽  
Environmental Attributes ◽  
Current Perspective ◽  
Genetic Resources Management ◽  
Definition Of ◽  
Experimental Trials

AbstractGenotype by Environment interaction (G × E) studies have focused mainly on estimating genetic parameters over a limited number of experimental trials. However, recent Geographic Information System (GIS) techniques have opened new frontiers for understanding and dealing with G × E. These advances allow increasing selection accuracy across all sites of interest, including those where experimental trials have not yet been deployed. Here, we introduce the term Enviromics under an envirotypic-assisted breeding framework and propose the GIS-GE method, i.e. a geospatial tool to maximize genetic gains by predicting the phenotypic performance of unobserved genotypes using “enviromic markers”. In summary, a particular site represents a set of envirotypes, each one representing a set of environmental factors that interact with the genetic background of genotypes, thus resulting in informative re-rankings to make decisions over different environments. Based on a simulated case study, we show that GIS-GE allows accurate (i) matching of genotypes to their most appropriate sites; (ii) definition of breeding areas that have high genetic correlation to ensure selection gains across environments; and (iii) indication of the best sites to carry out experiments for further analysis based on environments that maximize heritability. Envirotyping techniques provide a new class of markers for genetic studies, which are inexpensive, increasingly available and transferable across species. We envision a promising future for the integration of the Enviromics approach into breeding when coupled with next-generation genotyping/phenotyping and powerful statistical modeling of genetic diversity. Environmental scenarios can also be improved using information from strategic plans for biodiversity and genetic resources management, especially in the current perspective of dynamic climate change.Key messageWe propose the application of Enviromics to breeding practice, by which the similarity among sites assessed on an “omics” scale of environmental attributes drives the prediction of unobserved genotypes.

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