scholarly journals Pengaruh Komponen Neraca Air Terhadap Produktivitas Kelapa Sawit pada Berbagai Jenis Tanah:: Studi Kasus Kalimantan Tengah dan Barat

2021 ◽  
Vol 29 (1) ◽  
pp. 11-20
Author(s):  
Adhy Ardiyanto ◽  
Kukuh Murtilaksono ◽  
Enni Dwi Wahjunie ◽  
Atang Sutandi
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Stepwise Regression ◽  
Series Analysis ◽  
Area 5 ◽  
Area 6

Perbedaan jenis tanah dan letak geografis kebun kelapa sawit menyebabkan variasi sifat fisik tanah (terutama tekstur dan porositasnya).  Perbedaan letak geografis juga menyebabkan variasi jumlah curah hujan yang mempengaruhi neraca air lahan. Respons fluktuasi produksi kelapa sawit yang berbeda akibat variasi jenis tanah dan neraca air lahan dapat dikaji dengan analisis hubungan neraca air lahan dan produktivitas kelapa sawit antar jenis tanah dan antar wilayah. Pada penelitian ini, analisis neraca air lahan dilakukan pada tiga lokasi area perkebunan kelapa sawit PT Bumitama Gunajaya Agro yang berada di provinsi Kalimantan Tengah dan Kalimantan Barat, menggunakan metode Thornthwaite-Mather. Analisis hubungan komponen neraca air dengan produksi TBS kelapa sawit dihitung berdasarkan data bulanan selama 8 tahun (2012 – 2019) menggunakan time series analysis dan untuk mencari model regresi terbaik digunakan stepwise regression.  Komponen neraca air yang paling mempengaruhi produksi tandan buah segar (TBS) kelapa sawit (ton/ha/bulan) adalah curah hujan 7 bulan sebelum panen, hari hujan 11 dan 28 bulan sebelum panen, dan defisit air 10 bulan sebelum panen.  Penurunan produksi TBS (ton/ha/bulan) terjadi setiap ada kenaikan defisit air senilai 10 mm/bulan pada tanah Dystrudept, Paleudults dan Haplohumods di Area 3 berturut-turut adalah 11, 2, dan 3%. Pada Area 5 penurunannya adalah 12, 4, dan 5%. Pada Area 6 penurunannya adalah 5, 18 dan 3%.

scholarly journals Economics of apple-storage I: Comparative time series analysis of apple producer prices in Germany and Hungary

2010 ◽  
Vol 16 (4) ◽  
Author(s):  
Z. Lakner ◽  
F. Apáti
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Stepwise Regression ◽  
Storage Capacity ◽  
Arima Models ◽  
Domestic Markets ◽  
Series Analysis ◽  
Econometric Methods ◽  
Producer Prices ◽  
High Storage

Based on standard econometric methods the article analyses the time series of fresh apple producer prices in domestic markets of Germany and Hungary. In Germany, as a consequence of high storage capacities the quantity offered in different parts of the season is relatively stable, that’s why only a rather limited price increasing can be detected. In Hungary, as a consequence of the limited storage capacity this fluctuation is much more important. The modern methods of time series analysis (ARIMA models, stepwise regression) can be efficiently applied for forecasting of price movements.

Dynamical Peculiarities of Concatenational Changes in Functional Cardiovascular Parameters

2018 ◽  
Vol 3 (82) ◽  
Author(s):  
Eurelija Venskaitytė ◽  
Jonas Poderys ◽  
Tadas Česnaitis
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Functional State ◽  
The Body ◽  
Functional Changes ◽  
High Intensity Training ◽  
Series Analysis ◽  
Greco Roman ◽  
St Segment ◽  
Standard Lead

Research  background  and  hypothesis.  Traditional  time  series  analysis  techniques,  which  are  also  used  for the analysis of cardiovascular signals, do not reveal the relationship between the  changes in the indices recorded associated with the multiscale and chaotic structure of the tested object, which allows establishing short-and long-term structural and functional changes.Research aim was to reveal the dynamical peculiarities of interactions of cardiovascular system indices while evaluating the functional state of track-and-field athletes and Greco-Roman wrestlers.Research methods. Twenty two subjects participated in the study, their average age of 23.5 ± 1.7 years. During the study standard 12 lead electrocardiograms (ECG) were recorded. The following ECG parameters were used in the study: duration of RR interval taken from the II standard lead, duration of QRS complex, duration of JT interval and amplitude of ST segment taken from the V standard lead.Research  results.  Significant  differences  were  found  between  inter-parametric  connections  of  ST  segment amplitude and JT interval duration at the pre and post-training testing. Observed changes at different hierarchical levels of the body systems revealed inadequate cardiac metabolic processes, leading to changes in the metabolic rate of the myocardium and reflected in the dynamics of all investigated interactions.Discussion and conclusions. It has been found that peculiarities of the interactions of ECG indices interactions show the exposure of the  functional changes in the body at the onset of the workload. The alterations of the functional state of the body and the signs of fatigue, after athletes performed two high intensity training sessions per day, can be assessed using the approach of the evaluation of interactions between functional variables. Therefore the evaluation of the interactions of physiological signals by using time series analysis methods is suitable for the observation of these processes and the functional state of the body.Keywords: electrocardiogram, time series, functional state.

The Contribution of Foreign Direct Investment for Economic Growth of Ethiopia: Time Series Analysis

2018 ◽  
Vol 9 (02) ◽  
Author(s):  
Addissie Melak
Keyword(s):  
Economic Growth ◽  
Time Series ◽  
Foreign Direct Investment ◽  
Time Series Analysis ◽  
Direct Investment ◽  
Policy Framework ◽  
Annual Growth Rate ◽  
African Countries ◽  
Series Analysis ◽  
Integration Test

Economic growth of countries is one of the fundamental questions in economics. Most African countries are opening their economies for welcoming of foreign investors. As such Ethiopia, like many African countries took measures to attract and improve foreign direct investment. The purpose of this study is to examine the contribution of foreign direct investment (FDI) for economic growth of Ethiopia over the period of 1981-2013. The study shows an overview of Ethiopian economy and investment environment by the help of descriptive and econometric methods of analysis to establish empirical investigation for the contribution of FDI on Ethiopian economy. OLS method of time series analysis is employed to analyse the data. The stationary of the variables have been checked by using Augmented Dickey Fuller (ADF) Unit Root test and hence they are stationery at first difference. The co- integration test also shows that there is a long run relationship between the dependent and independent variables. Accordingly, the finding of the study shows that FDI, GDP per capita, exchange rate, total investment as percentage of GDP, inflow of FDI stock, trade as percentage of GDP, annual growth rate of GDP and liberalization of the economy have positive impact on Ethiopian GDP. Whereas Gross fixed domestic investment, inflows of FDI and Gross capital formation influence economic growth of Ethiopia negatively. This finding suggests that there should be better policy framework to attract and improve the volume of FDI through creating conducive environment for investment.

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