scholarly journals Chaos in Three-Body Dynamics: Intermittency, Strange Attractor, Kolmogorov-Sinai Entropy

1999 ◽  
Vol 172 ◽  
pp. 465-466
Author(s):  
Arthur D. Chernin
Keyword(s):  
Time Series ◽  
Temporal Structure ◽  
High Amplitude ◽  
Close Binary ◽  
Body Dynamics ◽  
Long Time ◽  
History Of ◽  
Three Body ◽  
Similarity And Difference ◽  
Low Amplitude

The temporal structure of chaos in three-body dynamics is analyzed; the emphasis is made on a similarity and difference between three-body chaos and basic patterns of chaotic behaviour known in nonlinear physics.1. With the use of homology mapping (Agekian and Anosova 1967), we study a set of computer models of thee-body systems in a stationary spherically symmetric potential well (Valtonen et al. (1994); the well confines the bodies, and because of this the system can generate fairly long time series. Typical time series reveal sequences of seemingly periodic motion and short bursts of strong chaos that appear in an irregular manner (Heinämäki et al. 1998). The quasi-ordered states are associated with hierarchical homology, and the quasi-period of the low-amplitude oscillations is very near the period of the temporary close binary in the system. The high-amplitude irregular states are mostly due to active three-body interplay when each of the bodies interacts with the two others with almost equal intensity. In the evolutionary history of most systems, these two extreme kinds of states alternate in an apparently random way producing together a non-stationary pattern of unpredictable behaviour.

scholarly journals The five million bird eggs in the world’s museum collections are an invaluable and underused resource

The Auk ◽  
2020 ◽  
Vol 137 (4) ◽  
Author(s):  
Miguel Ângelo Marini ◽  
Linnea Hall ◽  
John Bates ◽  
Frank D Steinheimer ◽  
Robert McGowan ◽  
...  
Keyword(s):  
Time Series ◽  
Scientific Community ◽  
Recent Literature ◽  
Spatial Scales ◽  
Museum Collections ◽  
Scientific Disciplines ◽  
Bird Eggs ◽  
Long Time ◽  
History Of ◽  
Avian Biology

Abstract The ~1.97 million egg sets (~5 million eggs) housed in museums have not been used in proportion to their availability. We highlight the wide variety of scientific disciplines that have used egg collections and the geographic locations and sizes of these collections, to increase awareness of the importance of egg collections, improve their visibility to the scientific community, and suggest that they offer a wealth of data covering large spatial scales and long time series for broad investigations into avian biology. We provide a brief history of egg collections and an updated list of museums/institutions with egg collections worldwide. We also review the limitations, challenges, and management of egg collections, and summarize recent literature based on historical and recent museum egg materials.

scholarly journals A History of Open Weather in New Zealand (HOWNZ): an open access 1-km resolution monthly 1910–2019 time-series of interpolated temperature and rainfall grids with associated uncertainty

2021 ◽  
Author(s):  
Thomas R. Etherington ◽  
George L. W. Perry ◽  
Janet M. Wilmshurst
Keyword(s):  
Time Series ◽  
New Zealand ◽  
Air Temperature ◽  
Temporal Trends ◽  
Spatial Uncertainty ◽  
Daily Maximum ◽  
Long Time ◽  
Ecological Patterns ◽  
History Of ◽  
Patterns And Processes

Abstract. Long time-series of weather grids are fundamental to understanding how weather affects environmental or ecological patterns and processes such as plant distributions, plant and animal phenology, wildfires, and hydrology. Ideally such weather grids should be openly available and be associated with uncertainties so that users can understand any data quality issues. We present a History of Open Weather in New Zealand (HOWNZ) that uses climatological aided natural neighbour interpolation to provide monthly 1-km resolution grids of total rainfall, mean air temperature, mean daily maximum air temperature, and mean daily minimum air temperature across New Zealand from 1910 to 2019. HOWNZ matches the best available temporal extent and spatial resolution of any open weather grids that include New Zealand, and is unique in providing associated spatial uncertainty in appropriate units of measurement. The HOWNZ weather and uncertainty grids capture the dynamic spatial and temporal nature of the monthly weather variables and the uncertainty associated with the interpolation. We also demonstrate how to quantify and visualise temporal trends across New Zealand that recognise the temporal and spatial variation of uncertainties in the HOWNZ data. The HOWNZ data is openly available at https://doi.org/10.7931/zmvz-xf30 (Etherington et al., 2021).

scholarly journals Putative GH pulse renewal: periventricular somatostatinergic control of an arcuate-nuclear somatostatin and GH-releasing hormone oscillator

2004 ◽  
Vol 286 (6) ◽  
pp. R1030-R1042 ◽  
Author(s):  
Leon S. Farhy ◽  
Johannes D. Veldhuis
Keyword(s):  
High Amplitude ◽  
Computer Assisted ◽  
Construction Time ◽  
Releasing Hormone ◽  
Gh Secretion ◽  
Adult Rat ◽  
Long Time ◽  
Time Latency ◽  
Regulatory Loci ◽  
Low Amplitude

Growth hormone (GH) pulsatility requires periventricular-nuclear somatostatin(SRIFPeV), arcuate-nuclear (ArC) GH-releasing hormone (GHRH), and systemic GH autofeedback. However, no current formalism interlinks these regulatory loci in a manner that generates self-renewable GH dynamics. The latter must include in the adult rat 1) infrequent volleys of high-amplitude GH peaks in the male, 2) frequent discrete low-amplitude GH pulses in the female, 3) disruption of the male pattern by severing SRIFPeV outflow to ArC, 4) stimulation of GHRH and GH secretion by central nervous system delivery of SRIF, 5) inhibition of GH release by central exposure to GHRH, and 6) a reboundlike burst of GHRH secretion induced by stopping peripheral infusion of SRIF. The present study validates by computer-assisted simulations a simplified ensemble formulation that predicts each of the foregoing six outcomes, wherein 1) blood-borne GH stimulates SRIFPeV secretion after a long time latency, 2) SRIFPeV inhibits both pituitary GH and ArC GHRH release, 3) ArC GHRH and SRIFArC oscillate reciprocally with brief time delay, and 4) SRIFPeV represses and disinhibits the putative GHRH-SRIFArC oscillator. According to the present analytic construction, time-delayed feedforward and feedback signaling among SRIFPeV, ArC GHRH, and SRIFArC could endow the complex physiological patterns of GH secretion in the male and female.

scholarly journals Amplitude variability in γ Dor and δ Sct stars observed by the Kepler spacecraft

2015 ◽  
Vol 11 (A29B) ◽  
pp. 560-566
Author(s):  
Joyce A. Guzik ◽  
Katie Kosak ◽  
Paul A. Bradley ◽  
Jason Jackiewicz
Keyword(s):  
Time Series ◽  
Wavelet Analysis ◽  
Variable Star ◽  
Recent Literature ◽  
Amplitude Spectrum ◽  
Amplitude Variability ◽  
Long Time ◽  
Spacecraft Data ◽  
Low Amplitude ◽  
Frequency Variations

AbstractThe NASA Kepler spacecraft data revealed a large number of multimode nonradially pulsating γ Dor and δ Sct variable star candidates. The Kepler high precision long time-series photometry makes it possible to study amplitude variations of the frequencies. We summarize recent literature on amplitude and frequency variations in pulsating variables. We are searching for amplitude variability in several dozen faint γ Doradus or δ Scuti variable-star candidates observed as part of the Kepler Guest Observer program. We apply several methods, including a Matlab-script wavelet analysis developed by J. Jackiewicz, and the wavelet technique of the VSTAR software (http://www.aavso.org/vstar-overview). Here we show results for two stars, KIC 2167444 and KIC 2301163. We discuss the magnitude and timescale of the amplitude variations, and the presence or absence of correlations between amplitude variations for different frequencies of a given star. Amplitude variations may be detectable using Kepler data even for stars with Kepler magnitude > 14 with low-amplitude frequencies (~100 ppm) using only one or a few quarters of long-cadence data. We discuss proposed causes of amplitude spectrum variability that will require further investigation.

scholarly journals Flood history of the Bavarian Alpine Foreland since the late Middle Ages in the context of internal and external climate forcing factors

2014 ◽  
Vol 11 (7) ◽  
pp. 7409-7440 ◽  
Author(s):  
O. Böhm ◽  
J. Jacobeit ◽  
R. Glaser ◽  
K.-F. Wetzel
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Climate Variability ◽  
Little Ice Age ◽  
Ice Age ◽  
Natural Climate Variability ◽  
Long Time ◽  
History Of ◽  
Alpine Foreland ◽  
Natural Climate

Abstract. This paper describes the flood history of the Bavarian part of the Alpine Foreland of Germany and addresses different questions concerning climate variability and flood frequencies from the 13th century until today. Will recent climatic change modify the flood frequencies within the Bavarian Alpine Foreland or are the flood frequencies varying due to altering climatic conditions since historical times? In the context of recent discussions whether man-made climate change will modify the present state of flood frequencies, a look back into the past is essential to understand the occurrence of floods in general and of recent floods in particular. In order to understand climatic variability and changes in a comprehensive way, it is necessary to review long time series. A perceived increase of summer floods in eastern Germany and Bavaria since 1997 requires examination of long time series to estimate changes in flood frequencies in a proper way. In view of the annual distribution of flood events within the Alpine Foreland of Germany, summer floods prove to be most important. Based on written historical sources, the flood history of the Alpine Foreland of Germany can be reconstructed back to the 14th century. One major result is the occurrence of "flood-rich" and "flood-poor" episodes in nearly cyclical sequences. Flood-rich periods were recorded in the periods 1300–1335, 1370–1450, 1470–1525, 1555–1590, 1615–1665, 1730–1780, 1820–1870, and 1910–1955 as well as in a 9th period beginning in 1980. The flood-rich periods are characterized by longer flood durations. Most of the flood-rich and flood-poor periods (in particular the beginning and the end of them) can be connected to changes in natural climate variability. These include changing sunspot numbers (as a measure of solar activity), so-called Little Ice Age Type Events (LIATEs) as well as changes in the North Atlantic Oscillation (NAO). Climate signals from external forcing factors, which could be used to explain the changing flood frequencies in the Bavarian Alpine Foreland, end in 1930. Relationships within the climate system such as the correlation of flood frequencies with the NAO have changed during the transition from the post Little Ice Age period to the Modern Climate Optimum around 1930. Natural climate variability might have been outperformed by anthropogenic climate change.

BRIDGE BUILDING AS A PROBLEM OF URBAN INFRASTRUCTURE DEVELOPMENT IN THE EUROPEAN NORTH OF RUSSIA IN THE EARLY XX CENTURY

2019 ◽  
Vol 15 (2) ◽  
pp. 125-135
Author(s):  
Tatiana S. Minaeva ◽  
Sergey S. Gulyaev
Keyword(s):  
Urban Infrastructure ◽  
Local Administration ◽  
Infrastructure Development ◽  
European North ◽  
Long Time ◽  
History Of ◽  
Floating Bridge ◽  
Historical Comparative ◽  
Bridge Building ◽  
Xix Century

Introduction. The organization of transport links and the bridge building in cities located on the banks of wide rivers has always been one of the most important tasks of the local administration. The study of the history of bridge building allows not only to trace the process of modernization of different regions of the country, but also to help in solving similar problems of our time. Nevertheless, the history of Russian bridge building is poorly studied. The purpose of the article is to determine the characteristics and features of the organization of bridge building in big cities of the European North of Russia as a way to solve one of the problems of urban infrastructure in the early XX century. Materials and Methods. The sources for this study are the documents of the State archive of the Arkhangelsk region, published documents on the history of Vologda, articles in the local periodicals of the early XX century. The analysis of the studied problem used a systematic approach, the method of economic analysis, historical and historical-comparative methods. Results and Discussion. The building of permanent bridges was a need for the development of Arkhangelsk and Vologda. In Vologda the two wooden bridges were built in the middle of XIX century on city funds and in the future these bridges were repaired or rebuilt. The Arkhangelsk city authorities did not hurry to solve a problem of city infrastructure by own efforts and a long time they used the floating bridge. The lack of experience in the building of large bridges and the desire to save money led to the rapid destruction of the first permanent bridge in Arkhangelsk. Conclusion. The Development of trade and industry in cities of the European North of Russia, such as Arkhangelsk and Vologda, led to the expansion of their territory and the emergence over time, the so-called third parts of the cities. Despite the comparable size of the population of the districts located across the river, the process of connecting them with bridges to the rest of the city went at different rates, which depended on the attitude of the local administration to the problem of urban infrastructure.

نظام التوثيق وأثره في إدارة الأصول الوقفية في دولة الإمارات العربية المتحدة: نماذج من إمارة الشارقة (Documentation System and its Impact on Endowment Managements in United Arabic Emirates: The Study of Emirate of Sharjah)

2019 ◽  
Vol 16 (2) ◽  
pp. 166-193
Author(s):  
مها بنت منصور الصائغ
Keyword(s):  
Human Life ◽  
Documentation System ◽  
The People ◽  
Endowment Management ◽  
Long Time ◽  
History Of ◽  
The Law

شهد تاريخ الأمة الإسلامية حضارة ونهضة عالمية في جميع مجالات الحياة الإنسانية، ومما كان له كبير الأثر في ذلك هو الأوقاف التي بدأت مع سيد البشرية محمد صلى الله عليه وسلم واستمرت بتنوع وشمولية إلى عصرنا الحالي؛ ولكن ما تعرضت إليه الأوقاف من إهمال وإقصاء وضياع يرجع لأسباب عديدة من أهمها غياب التوثيق الوقفي. تقوم الدراسة على تتبع مفهوم الوقف والتوثيق، والوقف في الإمارات العربية المتحدة ول سيما في إمارة الشارقة. توصلت الدراسة إلى نتائج منها: أن الأوقاف قائمة منذ زمن بعيد، وأن رغبة الواقف بالوقف وإقدامه عليها لم ينقصها سوى وثيقة، وأنه لا وثائق لها ولا مستندات، كما أن العرض الموجز لنشأة دائرة الأوقاف بالشارقة وسعيها لإحياء سنة الوقف ونشر ثقافته نراه يتضح شيئاً فشيئاً من خلال تفعيل مواد القانون والبحث حول الأنسب والأصح لحماية الأوقاف، ولم يكن هذا الاهتمام بالوقف إلا انعكاساً لتوجه الواقفين وتماشياً لرؤية الحكام وامتثالاً لنهج خير الأنام ورغبة في تكافل الأرواح وحباً للسلام. الكلمات المفتاحيّة: الوقف، التوثيق، المقارنة، الشارقة. Abstract The history of Islamic nation has witnessed a global civilization and it has had a great impact in all areas of human life, including the endowments that began with the master of humankind; Muhammad S.A.W. and it was continuing in diversity and comprehensively until our epoch. However, there are some problems related to endowment management such as negligence, exclusion and loss that due to many reasons. Among the most important reasons is the absence of endowment documentations. Therefore, the study aims to discuss the concept of endowment and documentation, as well as the endowment in United Arabic Emirates, especially in the Emirate of Sharjah. The study concluded that the practice of endowment has been existed for a long time, yet there are in need of endowment documentations. This study also found that the information related to the establishment of institution of endowment in Sharjah and its role has   spread widely to the people through the enforcement of the law and the implementation of the research related to the practice of endowment in order to sustain them in a good way. This documentation system was only a reflection of what has  stated in Shariah laws regarding the practice of endowment among the donors, so that it will be in line with the approach of good intentions and love of peace. Keywords: Endowment, Documentation, Comparison, Sharjah.   

Vestimental Fashion-Trends in the Context of Culture of the late XIX – early XX century: Experience of Inclusion in the Process of Teaching the History of World Culture

2020 ◽  
Author(s):  
Ж.В. Васильева
Keyword(s):  
Educational Material ◽  
Fundamental Importance ◽  
World Culture ◽  
Modern Period ◽  
Long Time ◽  
History Of ◽  
Experience Of Inclusion

вопросы взаимодействия моды и сферы искусства, аспекты сближения их позиций в области репрезентации базовых эстетических установок конца XIX – начала XX вв. долгое время оставались вне поля исследовательского внимания культурологов и искусствоведов. Между тем, для преподавания курса мировой художественной культуры (МХК) анализ динамики взаимопроникновения моды и искусства в период модерна, выявление параллелей в развитии фэшн-трендов и художественных направлений конца XIX – начала ХХ в. имеет принципиальное значение. Обосновать необходимость включения учебного материала по вестиментарным фэшн-трендам в курс МХК – наша задача. questions of interaction between fashion and art, aspects of convergence of their positions in the field of representation of basic aesthetic attitudes of the late XIX – early XX centuries for a long time remained out of the field of attention of researchers. Meanwhile, for teaching the history of world culture, the analysis of the dynamics of the interpenetration of fashion and art in the modern period, the identification of parallels in the development of fashion trends and artistic trends of the late XIX – early XX century is of fundamental importance. Our task is to justify the need to include educational material on vestigial fashion trends in the course of world art culture.

The Tangled Tale of Phase Space

2018 ◽  
Author(s):  
David D. Nolte
Keyword(s):  
Phase Space ◽  
Chaotic Behavior ◽  
Three Body Problem ◽  
Henri Poincaré ◽  
History Of ◽  
The Stability ◽  
Three Body ◽  
Space Phase ◽  
Central Paradigm ◽  
System Phase

This chapter presents the history of the development of the concept of phase space. Phase space is the central visualization tool used today to study complex systems. The chapter describes the origins of phase space with the work of Joseph Liouville and Carl Jacobi that was later refined by Ludwig Boltzmann and Rudolf Clausius in their attempts to define and explain the subtle concept of entropy. The turning point in the history of phase space was when Henri Poincaré used phase space to solve the three-body problem, uncovering chaotic behavior in his quest to answer questions on the stability of the solar system. Phase space was established as the central paradigm of statistical mechanics by JW Gibbs and Paul Ehrenfest.

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