scholarly journals The Main Component Analysis of the Longitudinal Distribution of Solar Activity

1991 ◽  
Vol 130 ◽  
pp. 275-276
Author(s):  
Ladislav Hejna ◽  
Hubertus Wöhl
Keyword(s):  
Time Series ◽  
Solar Activity ◽  
Sunspot Group ◽  
Component Analysis ◽  
Longitudinal Distribution ◽  
Sunspot Activity ◽  
Significant Feature ◽  
Solar Cycles ◽  
Main Component Analysis ◽  
Main Component

Abstract In this contribution, preliminary results of the main component analysis of Bartels diagram of time series of daily values of sunspot group numbers for solar cycles 18, 19 and 20 are presented. The results obtained suggest that the most significant feature in the longitudinal distribution of sunspot activity is the existence of preferred solar hemispheres alternating with a mean period of 2.5 Bartels rotations.

scholarly journals Complexes of activity on the Sun in solar cycle 21

2021 ◽  
pp. 3-9
Author(s):  
Sergey Yazev ◽  
Maria Ulianova ◽  
Elena Isaeva
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Natural Environment ◽  
Statistical Data ◽  
Sunspot Activity ◽  
The Sun ◽  
Solar Cycles ◽  
The North ◽  
South Asymmetry

The paper provides statistical data on solar activity complexes (ACs) observed in solar cycle 21. From the synoptic charts for the 1976–1986 sunspot activity, we have detected the regions where the sunspot generation was observed at least through three Carrington Rotations (CRs). These regions were identified as AC cores. We have compiled an AC catalogue. ACs are shown to evolve quasi-periodically, in pulses that are 15–20 rotations long. We have analyzed the North-South asymmetry in the AC location. In cycle 21, 90 % of the proton flares that affected the natural environment are shown to have occurred in ACs. We note a tendency for AC activity to decrease, as well as the manifestation of the Gnevyshev—Ohl rule in AC properties, in solar cycles 21–24.

scholarly journals Youth spare time: Typical patterns of behavior

Sociologija ◽  
2009 ◽  
Vol 51 (3) ◽  
pp. 247-261
Author(s):  
Ivana Stepanovic ◽  
Marina Videnovic ◽  
Dijana Plut
Keyword(s):  
Secondary School ◽  
Secondary School Students ◽  
Component Analysis ◽  
Free Time ◽  
School Students ◽  
Academic Orientation ◽  
Spare Time ◽  
Patterns Of Behavior ◽  
Main Component Analysis ◽  
Main Component

In this research we have tried to identify typical patterns of young people's behavior in their spare time and to use these patterns in order to group our subjects regarding their interests and preferences. Main-component analysis showed that it was possible to find different patterns of secondary school students' behavior in spare time as well as that the identified models could be the criteria for grouping them. Five patterns have been identified describing youth orientations towards their free time: academic orientation, orientation towards sports, orientation towards entertainment, orientation towards spending time going out and orientation towards music and computers.

scholarly journals KELIMPAHAN BIVALVIA DI EKOSISTEM LAMUN PANTAI PUDING KABUPATEN BANGKA SELATAN

2018 ◽  
Vol 12 (2) ◽  
pp. 64-75
Author(s):  
Mutiara Febrina ◽  
Wahyu Adi ◽  
Arief Febrianto
Keyword(s):  
Environmental Parameters ◽  
Component Analysis ◽  
Habitat Characteristics ◽  
Distribution Analysis ◽  
Seagrass Species ◽  
Total Percentage ◽  
Main Component Analysis ◽  
Main Components ◽  
Main Component ◽  
Abundance And Distribution

Puding Beach is administratively located in Pasir Putih Village, Tukak Sadai District, South Bangka Regency. As a coastal area, Puding Beach holds natural resource potential in both marine tourism and biota diversity. This study aims to analyze the abundance and distribution of bivalves and the seagrass beach community structure. This research was conducted in March 2018. The research method used was purposive sampling. Whereas for analysis of water quality characteristics and bivalve abundance, use main component analysis (Principle component analysis / PCA). The results showed that there were 6 species of seagrass and 7 species of bivalves at all stations. Each station I, II and III is dominated by the bivalve type Gafrarium tumidium with different seagrass species density. The highest density of seagrass species at stations I, II and III were Halodule uninervis (141 ind / m), Enhalus acoroides (7 ind / m) and Cymodocea serrulata (38 ind / m). Based on the analysis of main components can be seen the description of the condition to research location and can be seen the correlation between the existing bivalve abundance and the condition of the waters in all the research stations described in the F1-F2 factorial field. Important information on the main component axis is centered on the 2 main axes F1 (82.38%) and F2 (4.62%) of the total percentage. Bivalvia distribution analysis at Puding Beach is uniform and clustered based on habitat characteristics and environmental parameters that influence the life of bivalves

Image Tracking and Analysis Algorithm by Independent Component Analysis

2010 ◽  
Vol 44-47 ◽  
pp. 1622-1627
Author(s):  
Cheng Yi Yu ◽  
Yi Ying Chang ◽  
Yen Chieh Ouyang ◽  
Shen Chuan Tai ◽  
Tzu Wei Yu
Keyword(s):  
Independent Component Analysis ◽  
Natural Environment ◽  
Color Space ◽  
Component Analysis ◽  
Brightness Distribution ◽  
Target Object ◽  
Independent Component ◽  
Image Capture ◽  
Main Component Analysis ◽  
Main Component

Along with digitizing and multimedia era, the image has not changed from the original entity into any changes can be dealt with digital preservation methods. Although the digital image capture technology means more and more developed, but there are still many variables affect the quality of an image. An image quality usually depends on the user's usage or changes in the natural environment. Due to the natural environment of the most common factors that influence is light, so an image of the brightness distribution over the target object caused by extreme hardly recognizable condition common. Therefore, we will use the independent component analysis of an input color images Red, Green, and Blue three Color Space to the main component analysis, in order to achieve the target tracking and analysis.

scholarly journals Cosmogenic Radiocarbon and Cyclical Natural Processes

Radiocarbon ◽  
1995 ◽  
Vol 37 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Valentin Dergachev ◽  
Vladimir Chistyakov
Keyword(s):  
Time Series ◽  
Solar Activity ◽  
Tree Rings ◽  
Global Climate ◽  
Ice Cores ◽  
Cosmic Ray ◽  
Spectral Lines ◽  
Solar Cycles ◽  
Aurora Borealis ◽  
C Cycle

We investigated relations among solar activity, climate and cosmogenic radiocarbon in a time series of various astrophysical, geophysical, archaeological and historical data. We studied records of tree-ring thickness, aurora borealis, the catalog of visible sunspots, sedimentary deposits from lakes and oceans, global glacial advance and retreat chronology, polar ice cores and human migrations. In these data, we searched for evidence of medium- and long-term solar cycles. Application of different spectral techniques to the atmospheric 14C concentration time series indicates the existence of spectral lines at a few dominant periodicities ranging from 11 yr to ca. 2 ka. Different laboratories have confirmed the presence of the ca. 210-and 2000-yr spectral features in long 14C series in tree rings. The ca. 210-yr 14C cycle is probably caused by heliomagnetic modulation of the cosmic-ray flux. The extrema of both the ca. 210-yr 14C period and solar activity correlate with the cold and warm epochs of global climate, at least for the past millennium, and this correlation has the correct sign. The periods of low solar activity are well correlated with the Little Ice Ages. The cause of the ca. 2 ka 14C period is, as yet, uncertain, but evidence from the analyses of various natural records shows that it could have a solar origin. In this study, we obtained powerful manifestations of solar activity and climate warming epochs at ca. 1500, 3800, 6100, 8200, 10,500 and 12,600 bp. A similar feature occurs in epochs of minimum amplitude in the 14C content in tree rings. Thus, solar activity may affect both the 14C content in the Earth's atmosphere and climate.

scholarly journals Characterization, classification and analysis of the main properties of the Southwestern Goias soil

2016 ◽  
Vol 37 (3) ◽  
pp. 1135 ◽  
Author(s):  
Kathleen Lourenço Fernandes ◽  
Adriana Aparecida Ribon ◽  
José Marques Junior ◽  
Angélica Santos Rabelo de Souza Bahia ◽  
João Tavares Filho
Keyword(s):  
Management Practices ◽  
Principal Component ◽  
Soil Classification ◽  
Component Analysis ◽  
Minor Amount ◽  
Native Forest ◽  
Field Methods ◽  
Physical Chemical ◽  
Main Component Analysis ◽  
Main Component

Characterization of the soil and the grouping of its properties through main component analysis can assist in the classification and observation of the consequences of the conversion of native forest areas in pastures. Such data can aid in management practices. Considering the lack of studies in Cerrado soils of south-western Goias, developed metagranites of Jurubatuba suite, the objective was to classify and study the physical, chemical and mineralogical soil (under native forest and pasture) Southwest of Goias. Soil sampling and classification followed the Field Methods Manual and the Brazilian System of Soil Classification, respectively. The physical, chemical and mineralogical soil were studied, as well as main component analysis made for these attributes. The profile 1 under native forest was classified as “Cambissolo Háplico Tb eutrófico latossólico”. The profile 2 under degraded pasture was rated “Latossolo Amarelo eutrófico típico”. In addition, the profile 3 under rotated pasture was rated as “Latossolo Vermelho eutrófico chernossólico”. It was observed that the “Latossolos” have higher bulk density and soil penetration resistance, indicating greater soil compaction. They showed high amounts of iron oxides and minor amount of nutrients such as calcium and magnesium. The principal component analysis allowed the grouping of profiles into two groups. Group 1 brought together the properties related to “Latossolos”, and the second was related to “Cambissolo” properties. Thus, the principal components analysis aids the understanding of soil properties and the grouping of soils with similar characteristics, the level of order and management.

scholarly journals Modification of the solar activity indices in the International Reference Ionosphere IRI and IRI-Plas models due to recent revision of sunspot number time series

2016 ◽  
Vol 2 (3) ◽  
pp. 59-68 ◽  
Author(s):  
Тамара Гуляева ◽  
Tamara Gulyaeva
Keyword(s):  
Time Series ◽  
Solar Activity ◽  
Sunspot Number ◽  
International Reference Ionosphere ◽  
Electron Content ◽  
Prediction Errors ◽  
Solar Cycles ◽  
Total Electron ◽  
International Reference ◽  
Ionospheric Models

The International Reference Ionosphere (IRI) imports global effective ionospheric IG12 index based on ionosonde measurements of the critical frequency foF2 as a proxy of solar activity. Similarly, the global electron content (GEC), smoothed by the sliding 12-months window (GEC12), is used as a solar proxy in the ionospheric and plasmaspheric model IRI-Plas. GEC has been calculated from global ionospheric maps of total electron content (TEC) since 1998 whereas its productions for the preceding years and predictions for the future are made with the empirical model of the linear dependence of GEC on solar activity. At present there is a need to re-evaluate solar and ionospheric indices in the ionospheric models due to the recent revision of sunspot number (SSN2) time series, which has been conducted since 1st July, 2015 [Clette et al., 2014]. Implementation of SSN2 instead of the former SSN1 series with the ionospheric model could increase model prediction errors. A formula is proposed to transform the smoothed SSN212 series to the proxy of the former basic SSN112=R12 index, which is used by IRI and IRI-Plas models for long-term ionospheric predictions. Regression relationships are established between GEC12, the sunspot number R12, and the proxy solar index of 10.7 cm microwave radio flux, F10.712. Comparison of calculations by the IRI-Plas and IRI models with observations and predictions for Moscow during solar cycles 23 and 24 has shown the advantage of implementation of GEC12 index with the IRI-Plas model.

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