difference fields
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2021 ◽  
Vol 13 (8) ◽  
pp. 3885-3906
Author(s):  
Greg E. Bodeker ◽  
Jan Nitzbon ◽  
Jordis S. Tradowsky ◽  
Stefanie Kremser ◽  
Alexander Schwertheim ◽  
...  

Abstract. Total column ozone (TCO) data from multiple satellite-based instruments have been combined to create a single near-global daily time series of ozone fields at 1.25∘ longitude by 1∘ latitude spanning the period 31 October 1978 to 31 December 2016. Comparisons against TCO measurements from the ground-based Dobson and Brewer spectrophotometer networks are used to remove offsets and drifts between the ground-based measurements and a subset of the satellite-based measurements. The corrected subset is then used as a basis for homogenizing the remaining data sets. The construction of this database improves on earlier versions of the database maintained first by the National Institute of Water and Atmospheric Research (NIWA) and now by Bodeker Scientific (BS), referred to as the NIWA-BS TCO database. The intention is for the NIWA-BS TCO database to serve as a climate data record for TCO, and to this end, the requirements for constructing climate data records, as detailed by GCOS (the Global Climate Observing System), have been followed as closely as possible. This new version includes a wider range of satellite-based instruments, uses updated sources of satellite data, extends the period covered, uses improved statistical methods to model the difference fields when homogenizing the data sets, and, perhaps most importantly, robustly tracks uncertainties from the source data sets through to the final climate data record which is now accompanied by associated uncertainty fields. Furthermore, a gap-free TCO database (referred to as the BS-filled TCO database) has been created and is documented in this paper. The utility of the NIWA-BS TCO database is demonstrated through an analysis of ozone trends from November 1978 to December 2016. Both databases are freely available for non-commercial purposes: the DOI for the NIWA-BS TCO database is https://doi.org/10.5281/zenodo.1346424 (Bodeker et al., 2018) and is available from https://zenodo.org/record/1346424. The DOI for the BS-filled TCO database is https://doi.org/10.5281/zenodo.3908787 (Bodeker et al., 2020) and is available from https://zenodo.org/record/3908787. In addition, both data sets are available from http://www.bodekerscientific.com/data/total-column-ozone (last access: June 2021).


2021 ◽  
Vol 27 (2) ◽  
pp. 223-223
Author(s):  
Tingxiang Zou

AbstractThe thesis pseudofinite structures and counting dimensions is about the model theory of pseudofinite structures with the focus on groups and fields. The aim is to deepen our understanding of how pseudofinite counting dimensions can interact with the algebraic properties of underlying structures and how we could classify certain classes of structures according to their counting dimensions. Our approach is by studying examples. We treat three classes of structures: The first one is the class of H-structures, which are generic expansions of existing structures. We give an explicit construction of pseudofinite H-structures as ultraproducts of finite structures. The second one is the class of finite difference fields. We study properties of coarse pseudofinite dimension in this class, show that it is definable and integer-valued and build a partial connection between this dimension and transformal transcendence degree. The third example is the class of pseudofinite primitive permutation groups. We generalise Hrushovski’s classical classification theorem for stable permutation groups acting on a strongly minimal set to the case where there exists an abstract notion of dimension, which includes both the classical model theoretic ranks and pseudofinite counting dimensions. In this thesis, we also generalise Schlichting’s theorem for groups to the case of approximate subgroups with a notion of commensurability.Abstract prepared by Tingxiang Zou.E-mail: [email protected]: https://tel.archives-ouvertes.fr/tel-02283810/document


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 711
Author(s):  
Rana Ali Bakoban ◽  
Ashwaq Mohammad Al-Shehri

In this article, a new four-parameter lifetime model called the beta generalized inverse Rayleigh distribution (BGIRD) is defined and studied. Mixture representation of this model is derived. Curve’s behavior of probability density function, reliability function, and hazard function are studied. Next, we derived the quantile function, median, mode, moments, harmonic mean, skewness, and kurtosis. In addition, the order statistics and the mean deviations about the mean and median are found. Other important properties including entropy (Rényi and Shannon), which is a measure of the uncertainty for this distribution, are also investigated. Maximum likelihood estimation is adopted to the model. A simulation study is conducted to estimate the parameters. Four real-life data sets from difference fields were applied on this model. In addition, a comparison between the new model and some competitive models is done via information criteria. Our model shows the best fitting for the real data.


2020 ◽  
Author(s):  
Greg E. Bodeker ◽  
Jan Nitzbon ◽  
Jordis S. Tradowsky ◽  
Stefanie Kremser ◽  
Alexander Schwertheim ◽  
...  

Abstract. Total column ozone (TCO) data from multiple satellite-based instruments have been combined to create a single near-global daily time series of ozone fields at 1.25° longitude by 1° latitude spanning the period 31 October 1978 to 31 December 2016. Comparisons against TCO measurements from the ground-based Dobson and Brewer spectrophotometer networks are used to remove offsets and drifts between the ground-based measurements and a subset of the satellite-based measurements. The corrected subset is then used as a basis for homogenising the remaining data sets. The construction of this database improves on earlier versions of the database maintained first by the National Institute of Water and Atmospheric Research (NIWA) and now by Bodeker Scientific (BS), referred to as the NIWA-BS TCO database. The intention is that the NIWA-BS TCO database serves as a climate data record for TCO and, to this end, the requirements for constructing climate data records, as detailed by GCOS (the Global Climate Observing System) have been followed as closely as possible. This new version includes a wider range of satellite-based instruments, uses updated sources of satellite data, extends the period covered, uses improved statistical methods to model the difference fields when homogenising the data sets, and, perhaps most importantly, robustly tracks uncertainties from the source data sets through to the final climate data record which is now accompanied by associated uncertainty fields. Furthermore, a gap-free TCO database (referred to as the BS-filled TCO database) has been created and is documented in this paper. The utility of the NIWA-BS TCO database is demon strated through an analysis of ozone trends from November 1978 to December 2016. Both databases are freely available for non-commercial purposes: the doi for the NIWA-BS TCO database is 10.5281/zenodo.1346424 (Bodeker et al., 2018) and is available from https://zenodo.org/record/1346424. The doi for the BS-filled TCO database is 10.5281/zenodo.3908787 (Bodeker et al., 2020) and is available from https://zenodo.org/record/3908787. In addition, both data sets are available from http://www.bodekerscientific.com/data/total-column-ozone.


2020 ◽  
Vol 21 (01) ◽  
pp. 2050022
Author(s):  
Tingxiang Zou

We study a family of ultraproducts of finite fields with the Frobenius automorphism in this paper. Their theories have the strict order property and TP2. But the coarse pseudofinite dimension of the definable sets is definable and integer-valued. Moreover, we also discuss the possible connection between coarse dimension and transformal transcendence degree in these difference fields.


Author(s):  
Eunbi Ko ◽  
Youngseok Han

The purpose of this study is to investigate the effect of hierarchical organizational structure and performance-based human resource system on climate of silence and silence behavior and to reveal this process. Specifically, We will examine the effect the hierarchical organizational structure and performance-based human resource system on organizational silence, the dual mediated effects on climate of silence and psychological unsafety. A total of 300 employee working in a variety of difference fields in Korea participated in an on-line survey, These results showed that hierarchical organizational structure had a positive effect on climate of silence and Performance-based human resource system had a negative effect on climate of silence. Climate of silence had a positive effect on psychological unsafety and Psychological unsafety had a positive effect on defensive silence. The defensive silence a positive effect on acquiescent silence. The hierarchical organizational structure had a effect on defensive silence, through climate of silence and psychological unsafefy, and had a effect on acquiescent silence, through climate of silence, psychology unsafety, and defensive silence. this study is significance to integrately consider the effect of organizational structure, culture and Psychological factor on silence behavior. On the basis of the results, the implications and future research directions were discussed.


2019 ◽  
Vol 20 (01) ◽  
pp. 1993001
Author(s):  
Tingxiang Zou
Keyword(s):  

2019 ◽  
Vol 19 (02) ◽  
pp. 1950011
Author(s):  
Tingxiang Zou

We study a family of ultraproducts of finite fields with the Frobenius automorphism in this paper. Their theories have the strict order property and TP2. But the coarse pseudofinite dimension of the definable sets is definable and integer-valued. Moreover, we establish a partial connection between coarse dimension and transformal transcendence degree in these difference fields.


2019 ◽  
Vol 147 (10) ◽  
pp. 3595-3607 ◽  
Author(s):  
Sarah D. Ditchek ◽  
Kristen L. Corbosiero ◽  
Robert G. Fovell ◽  
John Molinari

Abstract While the frequency and structure of Atlantic basin tropical cyclone diurnal cooling and warming pulses have recently been explored, how often diurnal pulses are associated with deep convection was left unanswered. Here, storm-relative, GridSat-B1, 6-h IR brightness temperature difference fields were supplemented with World Wide Lightning Location Network (WWLLN) data to answer that question. Electrically active, long-lived cooling and warming pulses were defined objectively by determining critical thresholds for the lightning flash density, areal coverage, and longevity within each pulse. Pulses with lightning occurred 61% of the time, with persistently electrically active pulses (≥9 h, ACT) occurring on 38% of pulse days and quasi–electrically active pulses (3–6 h, QUASI) occurring on 23% of pulse days. Electrically inactive pulses (<3 h, INACT) occurred 39% of the time. ACT pulse days had more pulses located right-of-shear, the preferred quadrant for outer-rainband lightning activity, and were associated with more favorable environmental conditions than INACT pulse days. Cooling pulses were more likely to occur in lower-shear environments while warming pulses were more likely to occur in high-shear environments. Finally, while the propagation speeds of ACT and INACT cooling pulses and ACT warming pulses did lend support to the recent gravity wave and tropical squall-line explanations of diurnal pulses, the INACT warming pulses did not and should be studied further.


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