scholarly journals Solar-cycle, seasonal, and asymmetric dependencies of thermospheric mass density disturbances due to magnetospheric forcing

2019 ◽  
Author(s):  
Andres Calabia ◽  
Shuanggen Jin
Keyword(s):  
Principal Component Analysis ◽  
Solar Cycle ◽  
High Frequency ◽  
Mass Density ◽  
Principal Component ◽  
Component Analysis ◽  
Upper Atmosphere ◽  
Local Solar Time ◽  
Short Term ◽  
Solar Time

Abstract. Short-term upper atmosphere variations due to magnetospheric forcing are very complex, and neither well understood nor capably modelled due to limited observations. In this paper, mass density variations from 2003–2013 of GRACE observations are isolated through the parameterization of annual, Local-Solar-Time (LST), and solar-cycle fluctuations using a Principal Component Analysis (PCA) technique and investigated in terms of magnetospheric drivers. The magnitude of high-frequency (

Principal Component Analysis the Economy of Shanghai in 2010

2011 ◽  
Vol 50-51 ◽  
pp. 404-408
Author(s):  
Xiao Qiang Guo ◽  
Zhen Dong Li ◽  
Dong Dong Hao ◽  
Xin Xie ◽  
Jian Min Wang
Keyword(s):  
Principal Component Analysis ◽  
Economic Development ◽  
Principal Component ◽  
Component Analysis ◽  
Evaluation Index ◽  
Short Term ◽  
Construction Costs ◽  
World Expo ◽  
Shanghai World Expo

This paper from the economic analysis, quantitative evaluation of the 2010 Shanghai World Exop impact. First, from the short-term and long-term benefits of the two considerations, the loss of earnings, base construction costs on the percentage of total funding, permanent building retained, the number of daily tours, the number of participating countries for the evaluation index, subjectively weight to the five indicators，calculate its scores to rank for five World Expos including Shanghai World Expo. Second, using principal component analysis, we get the five indicators of objective weighting and ranking for above five World Expos. The results show that the Shanghai World Expo will boost the economic development and has a huge influence on the economy

scholarly journals Finanças pessoais: uma análise do comportamento de estudantes de Ciências Contábeis

2018 ◽  
Vol 17 (3) ◽  
pp. 819-840
Author(s):  
Mariana Ferreira Soares Marques ◽  
Renata Turola Takamatsu ◽  
Bruna Camargos Avelino
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Personal Finance ◽  
Self Control ◽  
Accounting Students ◽  
Short Term ◽  
Resources Management ◽  
Credit Supply ◽  
Payment Methods

Resumo: A forma como as pessoas lidam com suas finanças pessoais é um tema cada vez mais relevante diante da complexidade dos meios de pagamento atuais, das formas de investimento existentes e da oferta do crédito restrita. Neste estudo propõe-se a analisar como os estudantes de Ciências Contábeis da Universidade Federal de Minas Gerais (UFMG) têm gerenciado suas finanças, a propensão ao endividamento ou à poupança desses indivíduos e a influência de aspectos comportamentais — o autocontrole, a visão de curto prazo, a preferência por crédito e a propensão a planejar — na gestão dos recursos. Foi realizado um estudo quantitativo, com a aplicação de questionários a 104 estudantes. Os resultados da pesquisa foram analisados por meio da análise fatorial, testes de correlação e de diferenças de médias. Observou-se, de forma geral, que os acadêmicos de Ciências Contábeis são altamente bancarizados e, em grande parte, possuem poupança e realizam depósitos regulares. Foi identificada uma maior propensão à poupança em alunos inseridos em famílias com renda superior a R$ 5.201,00 e uma aversão a crédito de estudantes que poupam com a finalidade de prevenir emergências. A idade dos alunos não esteve correlacionada a nenhum padrão de comportamento.Palavras-chave: Finanças Pessoais. Propensão ao endividamento. Propensão à poupança.Personal finance: an analysis of Undergraduate Accounting students behavior  Abstract: The ways in which people deal with money is relevant given the complexity of current payment methods, existing types of investment and the credit supply restrictions. This research's aim was to assess how Undergraduate Accounting students manage their finances, their propensity for getting into debt, propensity to save and analyze how behavioral aspects (self-control, short-term thinking, preference for credit and propensity to plan) influence resources’ management. We have applied a questionnaire to 104 students.  We used principal component analysis, correlations and tests of differences between means. The results suggest that Accounting students are highly banked and, most of them have savings account and make periodic deposits. We have identified a higher Propensity to save money in families with incomes greater than R$ 5.201,00 and debt aversion of students who save to prevent emergencies. Student's age was not correlated with any behavior pattern.Keywords: Personal Finance. Propensity to save. Propensity for getting into debt.

scholarly journals Principal component analysis identifies different representative match load profiles in international women’s field hockey based on playing positions. [El análisis de componentes principales identifica diferentes perfiles de rendimiento en función de las posiciones en partidos internacionales de hockey hierba femenino].

2021 ◽  
Vol 17 (64) ◽  
pp. 112-123
Author(s):  
Esther Morencos ◽  
Blanca Romero-Moraleda ◽  
Markel Rico-González ◽  
Daniel Rojas-Valverde ◽  
José Pino-Ortega
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Field Hockey ◽  
Short Term ◽  
Strength And Conditioning ◽  
World Series ◽  
Repeated Sprint ◽  
Hockey Players ◽  
High Degree

The aim of this study was to assess the principal components (PC) of women’s field hockey players´ TL distinguishing by playing positions (i.e., back, midfielder, forward). Data were collected from sixteen players belonging to the Spanish National women’s field hockey team during 13 official matches from the European Championship, World Series, and Pre-Olympic tournament. The Principal Component Analysis (PCA) grouped a total of 16 variables in five to six PC, explaining between 68.6 and 80% of the total variance. Different variables formed the PC that explain the player’s performance in different field positions. There were differences by positions in the distance covered at 21 to 24 km·h-1 (midfielders>forwards), decelerations from 5 to 4 m·s-2 (midfielders>forwards), and in maximum accelerations (midfielders>backs). Overall, strength and conditioning coaches should combine exercises which induce a high degree of aerobic endurance and power. However, some specification should be made by playing position: (1) defenders should perform training sessions with at least the same amount of volume as in the matches; (2) forwards should perform training efforts that ensure high repeated sprint ability; and (3) midfielders should perform a high training volume to develop high-intensity aerobic endurance, in combination with short-term efforts.

scholarly journals Solar cycle, seasonal, and asymmetric dependencies of thermospheric mass density disturbances due to magnetospheric forcing

2019 ◽  
Vol 37 (5) ◽  
pp. 989-1003 ◽  
Author(s):  
Andres Calabia ◽  
Shuanggen Jin
Keyword(s):  
Solar Cycle ◽  
High Frequency ◽  
Polar Region ◽  
Rotation Axis ◽  
Mass Density ◽  
Principal Component ◽  
Geomagnetic Variation ◽  
The South ◽  
The North ◽  
Possible Cause

Abstract. Short-term upper atmosphere variations due to magnetospheric forcing are very complex, and neither well understood nor capably modeled due to limited observations. In this paper, mass density variations from 10 years of GRACE observations (2003–2013) are isolated via the parameterization of annual, local solar time (LST), and solar cycle fluctuations using a principal component analysis (PCA) technique. The resulting residual disturbances are investigated in terms of magnetospheric drivers. The magnitude of high-frequency (δ < 10 d) disturbances reveals unexpected dependencies on the solar cycle, seasonal, and an asymmetric behavior with smaller amplitudes in June in the south polar region (SPR). This seasonal modulation might be related to the Russell–McPherron (RM) effect. Meanwhile, we find a similar pattern, although less pronounced, in the northern and equatorial regions. A possible cause of this latitudinal asymmetry might be the irregular shape of the Earth's magnetic field (with the north dip pole close to Earth's rotation axis, and the south dip pole far from that axis). After accounting for the solar cycle and seasonal dependencies by regression analysis to the magnitude of the high-frequency perturbations, the parameterization in terms of the disturbance geomagnetic storm-time index Dst shows the best correlation, whereas the geomagnetic variation Am index and merging electric field Em are the best predictors in terms of time delay. We test several mass density models, including JB2008, NRLMSISE-00, and TIEGCM, and find that they are unable to completely reproduce the seasonal and solar cycle trends found in this study, and show a clear overestimation of about 100 % during low solar activity periods.

scholarly journals Collapse of Global Neuronal States in Caenorhabditis elegans under Isoflurane Anesthesia

2020 ◽  
Vol 133 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Mehraj R. Awal ◽  
Gregory S. Wirak ◽  
Christopher V. Gabel ◽  
Christopher W. Connor
Keyword(s):  
Principal Component Analysis ◽  
Caenorhabditis Elegans ◽  
Neuronal Activity ◽  
High Frequency ◽  
Dynamic Range ◽  
Functional Organization ◽  
Principal Component ◽  
Component Analysis ◽  
C Elegans ◽  
Light Sheet Microscopy

Background A comprehensive understanding of how anesthetics facilitate a reversible collapse of system-wide neuronal function requires measurement of neuronal activity with single-cell resolution. Multineuron recording was performed in Caenorhabditis elegans to measure neuronal activity at varying depths of anesthesia. The authors hypothesized that anesthesia is characterized by dyssynchrony between neurons resulting in a collapse of organized system states. Methods Using light-sheet microscopy and transgenic expression of the calcium-sensitive fluorophore GCaMP6s, a majority of neurons (n = 120) in the C. elegans head were simultaneously imaged in vivo and neuronal activity was measured. Neural activity and system-wide dynamics were compared in 10 animals, progressively dosed at 0%, 4%, and 8% isoflurane. System-wide neuronal activity was analyzed using principal component analysis. Results Unanesthetized animals display distinct global neuronal states that are reflected in a high degree of correlation (R = 0.196 ± 0.070) between neurons and low-frequency, large-amplitude neuronal dynamics. At 4% isoflurane, the average correlation between neurons is significantly diminished (R = 0.026 ± 0.010; P &lt; 0.0001 vs. unanesthetized) and neuron dynamics shift toward higher frequencies but with smaller dynamic range. At 8% isoflurane, interneuronal correlations indicate that neuronal activity remains uncoordinated (R = 0.053 ± 0.029; P &lt; 0.0001 vs. unanesthetized) with high-frequency dynamics that are even further restricted. Principal component analysis of unanesthetized neuronal activity reveals distinct structure corresponding to known behavioral states. At 4% and 8% isoflurane this structure is lost and replaced with randomized dynamics, as quantified by the percentage of total ensemble variance captured by the first three principal components. In unanesthetized worms, this captured variance is high (88.9 ± 5.4%), reflecting a highly organized system, falling significantly at 4% and 8% isoflurane (57.9 ± 11.2%, P &lt; 0.0001 vs. unanesthetized, and 76.0 ± 7.9%, P &lt; 0.001 vs. unanesthetized, respectively) and corresponding to increased randomization and collapse of system-wide organization. Conclusions Anesthesia with isoflurane in C. elegans corresponds to high-frequency randomization of individual neuron activity, loss of coordination between neurons, and a collapse of system-wide functional organization. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Sign in / Sign up

Export Citation Format

Share Document