scholarly journals Cluster as current sheet surveyor in the magnetotail

2013 ◽  
Vol 31 (9) ◽  
pp. 1605-1610 ◽  
Author(s):  
Y. Narita ◽  
R. Nakamura ◽  
W. Baumjohann
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Time Series Data ◽  
Sheet Thickness ◽  
Dynamical Evolution ◽  
Field Measurements ◽  
Three Dimensions ◽  
Series Data ◽  
Time Step ◽  
Analysis Technique

Abstract. A novel analysis technique is presented to estimate the current sheet thickness unambiguously and directly, without associating time series data with spatial structure. The technique is a combination of eigenvalue analysis and minimum variance estimator adapted to Harris current sheet geometry, and needs one-time, four-point magnetic field data as provided by the Cluster spacecraft. Two current sheet parameters, thickness and distance to the spacecraft, can be determined at each time step of the magnetic field measurements. An example is shown from a Cluster magnetotail crossing under quiet magnetospheric conditions, yielding the result that the current sheet thickness is on the scale of the proton gyroradius. The analysis technique can also be used to track the dynamical evolution of the current sheet structure in three dimensions.

ANALISA PREDIKSI INDEKS HARGA SAHAM GABUNGAN MENGGUNAKAN METODE ARIMA

2020 ◽  
Vol 2 (2) ◽  
pp. 454
Author(s):  
Julkifli Purnama ◽  
Ahmad Juliana
Keyword(s):  
Capital Market ◽  
Stock Price ◽  
Time Series Data ◽  
Arima Model ◽  
Secondary Data ◽  
Actual Data ◽  
Series Data ◽  
Analysis Technique ◽  
The Right ◽  
The Capital Market

Investment in the capital market every manager needs to analyze to make decisions so that the right target to produce profits in accordance with what is expected. For that, we need a way to predict the decisions that will be taken in the future. The research objective is to find the best model and forecasting of the composite stock price index (CSPI). Data analysis technique The ARIMA Model time series data from historical data is the basis for forecasting. Secondary data is the closing price of the JCI on July 16 2018 to July 16 2019 to see how accurate the forecasting is done on the actual data at that time. The results of the study that the best Arima model is Arima 2.1.2 with an R-squared value of 0.014500, Schwarz criterion 10.83497 and Akaike info criterion of 10.77973. Results of forecasting actual data are 6394,609, dynamic forecast 6387,551 selisish -7,05799, statistics forecas 6400,653 difference of 6,043909. For investors or the public can use the ARIMA method to be able to predict or predict the capital market that will occur in the next period.

scholarly journals Electric fields and double layers in plasmas

1987 ◽  
Vol 5 (2) ◽  
pp. 233-255 ◽  
Author(s):  
Nagendra Singh ◽  
H. Thiemann ◽  
R. W. Schunk
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Electric Fields ◽  
Sheet Thickness ◽  
High Density ◽  
Effective Length ◽  
Double Layers ◽  
Low Density ◽  
Ambient Magnetic Field ◽  
Cold Plasmas

Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamic features of the double layers are discussed. These features, as seen in simulations, laboratory experiments and theory, indicate that double layers and the currents through them undergo slow oscillations, which are determined by the ion transit time across an effective length of the system in which the double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations have been considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields (parallel to an ambient magnetic field) and double layers in an expanding plasma are discussed.

scholarly journals THE EFFECT OF CAPITAL EXPENDITURE AND ECONOMIC GROWTH ON THE HUMAN DEVELOPMENT INDEX OF THE DISTRICT CITY IN NORTH SUMATERA

2020 ◽  
Vol 7 (1) ◽  
pp. 585-594
Author(s):  
Muammar Rinaldi ◽  
Zainal Arifin ◽  
Indra Maipita ◽  
Saidun Hutasuhut
Keyword(s):  
Economic Growth ◽  
Human Development ◽  
Human Development Index ◽  
Time Series Data ◽  
Capital Expenditure ◽  
Numerical Data ◽  
Series Data ◽  
Development Index ◽  
Analysis Technique ◽  
North Sumatra

This study aims to analyze the effect of capital expenditure and economic growth simultaneously on the Human Development Index (HDI) in districts/cities in North Sumatra. This type of research is a descriptive-quantitative approach that suppresses its analysis of numerical data that is processed by the statistical method. Sources of data in this study were taken from the Central Bureau of Statistics of North Sumatra for the HDI data. The sample in this study is all districts/cities in North Sumatra for the period 2013-2017. The data analysis technique used in this study uses panel data regression with Eviews 7 because, in this study, there are characteristics of cross-section and time-series data simultaneously. The results of this study indicate that capital expenditure partially has a positive and significant effect on the Human Development Index in districts/cities in North Sumatra. Economic growth partially has a positive and significant effect on the HDI in districts/cities in North Sumatra, and capital expenditure and economic growth have a positive and significant effect simultaneously on the Human Development Index in districts/cities in North Sumatra.

scholarly journals The Spillover Effects on Strategic Interdependence Neighboring Countries: A Game Theory Approach

2021 ◽  
Author(s):  
Oyundelger Sharkhuu ◽  
Pu Yongjian ◽  
Batdelger Tsogt-Ochir ◽  
Tugs Sanjdorj
Keyword(s):  
Game Theory ◽  
Time Series Data ◽  
Spillover Effects ◽  
Three Dimensions ◽  
Series Data ◽  
Theory Approach ◽  
Vector Error Correction ◽  
Long Run ◽  
Inbound Tourism ◽  
Short Run

The main aim of sustainable development is to ensure an intelligible and long-lasting balance between the economy, society, and the environment. Sustainable tourism could only be successful if the inter-relationships between all three dimensions are accepted. In the limited number of research analyses, the focus of the research is on competition between tourist countries and destinations. This study has used Game theory to analyze the competition applies time-series data in selected neighboring countries measure of a VAR-based spillover index, developed by [1] to investigate the time-varying relationship between tourism and Gross Domestic Product. Each country analyzed Vector Error Correction (VEC) and Granger analysis to explore the causal short and long-term tourism and use a sample that spans from 1997 to 2019. From the main results of Cholesky, the total spillover index is 59.0% between Russia and Mongolia which suggests a moderate interdependence among the four variables. Findings indicate that neither China nor Mongolia have a short-run influence on tourism development. China's inbound tourism is affected in the long run by Mongolia's inbound tourism but not vice versa can be explained by the fact that the number of tourists visiting Mongolia would include China in their travels.

Pengaruh Nilai Tukar (Kurs) dan Inflasi terhadap Tingkat  Non Performing  Financing (NPF) Pada Bank Syariah

2019 ◽  
Vol 2 (2) ◽  
pp. 214-224
Author(s):  
Muhammad Arfan Harahap ◽  
Anjur Perkasa Alam ◽  
Muspita Pradila
Keyword(s):  
Exchange Rate ◽  
Time Series Data ◽  
Sampling Technique ◽  
Series Data ◽  
Islamic Banks ◽  
Exogenous Variables ◽  
Independent Variables ◽  
Analysis Technique ◽  
The Exchange Rate ◽  
Conventional Banks

The level of Non-Performing Financing at Islamic Banks is higher than conventional banks, while in terms of total assets, Islamic Banks are smaller. This study aims to analyze the effect of exogenous variables consisting of the level of inflation and the exchange rate of the rupiah against non Performing Financing in Islamic banks. This study uses time series data from 2016-2018. The population in this study consisted of Islamic Commercial Banks. The sampling technique used in this research is purposive sampling technique. The data analysis technique used is Multiple Linear Regression. The results showed that the inflation variable had a positive and significant effect on Non Performing Financing. While the Exchange Rate has no effect on Non Performing Finance. Meanwhile, simultaneously the two independent variables affect the independent variables.

scholarly journals Solitary potential structures observed in the magnetosheath by the Cluster spacecraft

2003 ◽  
Vol 10 (1/2) ◽  
pp. 3-11 ◽  
Author(s):  
J. S. Pickett ◽  
J. D. Menietti ◽  
D. A. Gurnett ◽  
B. Tsurutani ◽  
P. M. Kintner ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Time Series Data ◽  
Broad Band ◽  
Low Frequency ◽  
Bow Shock ◽  
Local Magnetic Field ◽  
Series Data ◽  
The Individual ◽  
Almost All ◽  
The Magnetic Field

Abstract. Bipolar pulses of ~ 25-100 µs in duration have been observed in the wave electric field data obtained by the Wideband plasma wave instrument on the Cluster spacecraft in the dayside magnetosheath. These pulses are similar in almost all respects to those observed on several spacecraft over the last few years. They represent solitary potential structures, and in this case, electron phase space holes. When the time series data containing the bipolar pulses on Cluster are transformed to the frequency domain by a windowed FFT, the pulses appear as typical broad-band features, extending from the low-frequency cutoff of the bandpass filter, ~ 1 kHz, up to as great as 20-40 kHz in some cases, with decreasing intensity as the frequency increases. The upper frequency cutoff of the broad band is an indication of the individual pulse durations (1/f). The solitary potential structures are detected when the local magnetic field is contained primarily in the spin plane, indicating that they propagate along the magnetic field. Their frequency extent and intensity seem to increase as the angle between the directions of the magnetic field and the plasma flow decreases from 90°. Of major significance is the finding that the overall profile of the broad-band features observed simultaneously by two Cluster spacecraft, separated by a distance of over 750 km, are strikingly similar in terms of onset times, frequency extent, intensity, and termination. This implies that the generation region of the solitary potential structures observed in the magnetosheath near the bow shock is very large and may be located at or near the bow shock, or be connected with the bow shock in some way.

scholarly journals Magnetic turbulence and particle dynamics in the Earth’s magnetotail

2003 ◽  
Vol 21 (9) ◽  
pp. 1947-1953 ◽  
Author(s):  
G. Zimbardo ◽  
A. Greco ◽  
A. L. Taktakishvili ◽  
P. Veltri ◽  
L. M. Zelenyi
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Sheet Thickness ◽  
Particle Dynamics ◽  
Particle Simulation ◽  
Mhd Waves ◽  
Magnetic Fluctuations ◽  
Magnetic Turbulence ◽  
Magnetospheric Configuration And Dynamics ◽  
Interplanetary Physics

Abstract. The influence of magnetic turbulence in the near-Earth magnetotail on ion motion is investigated by numerical simulation. The magnetotail current sheet is modelled as a magnetic field reversal with a normal magnetic field com-ponent Bn , plus a three-dimensional spectrum of magnetic fluctuations dB which represents the observed magnetic turbulence. The dawn-dusk electric field Ey is also considered. A test particle simulation is performed using different values of Bn and of the fluctuation level dB/B0. We show that when the magnetic fluctuations are taken into account, the particle dynamics is deeply affected, giving rise to an increase in the cross tail transport, ion heating, and current sheet thickness. For strong enough turbulence, the current splits in two layers, in agreement with recent Cluster observations.Key words. Magnetospheric physics (magnetospheric configuration and dynamics) – Interplanetary physics (MHD waves and turbulence) – Electromagnetics (numerical methods)

scholarly journals Are there current-sheet-like structures in the Earth's magnetotail as in the solar wind – results and implications from high time resolution magnetic field measurements by Cluster

2008 ◽  
Vol 26 (7) ◽  
pp. 1889-1895 ◽  
Author(s):  
G. Li ◽  
E. Lee ◽  
G. Parks
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Current Sheet ◽  
Time Resolution ◽  
Field Measurements ◽  
Solar Wind Plasma ◽  
High Time ◽  
High Time Resolution ◽  
Mhd Turbulence ◽  
Flux Tubes

Abstract. Recent studies of solar wind MHD turbulence show that current-sheet-like structures are common in the solar wind and they are a significant source of solar wind MHD turbulence intermittency. While numerical simulations have suggested that such structures can arise from non-linear interactions of MHD turbulence, a recent study by Borovsky (2006), upon analyzing one year worth of ACE data, suggests that these structures may represent the magnetic walls of flux tubes that separate solar wind plasma into distinct bundles and these flux tubes are relic structures originating from boundaries of supergranules on the surface of the Sun. In this work, we examine whether there are such structures in the Earth's magnetotail, an environment vastly different from the solar wind. We use high time resolution magnetic field data of the FGM instrument onboard Cluster C1 spacecraft. The orbits of Cluster traverse through both the solar wind and the Earth's magnetosheath and magnetotail. This makes its dataset ideal for studying differences between solar wind MHD turbulence and that inside the Earth's magnetosphere. For comparison, we also perform the same analysis when Cluster C1 is in the solar wind. Using a data analysis procedure first introduced in Li (2007, 2008), we find that current-sheet-like structures can be clearly identified in the solar wind. However, similar structures do not exist inside the Earth's magnetotail. This result can be naturally explained if these structures have a solar origin as proposed by Borovsky (2006). With such a scenario, current analysis of solar wind MHD turbulence needs to be improved to include the effects due to these curent-sheet-like structures.

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