scholarly journals A Tree Ring Measurement Method Based on Error Correction in Digital Image of Stem Analysis Disk

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 464
Author(s):  
Wenjie Zhang ◽  
Tianzhong Zhao ◽  
Xiaohui Su ◽  
Baoguo Wu ◽  
Zhiqiang Min ◽  
...  
Keyword(s):  
Error Correction ◽  
Tree Ring ◽  
Tree Rings ◽  
Digital Image ◽  
Regression Equation ◽  
Distortion Correction ◽  
Geometric Distortion ◽  
Stem Analysis ◽  
Correction Model ◽  
Ring Radius

Stem analysis is an essential aspect in forestry investigation and forest management, as it is a primary method to study the growth law of trees. Stem analysis requires measuring the width and number of tree rings to ensure the accurate measurement, expand applicable tree species, and reduce operation cost. This study explores the use of Open Source Computer Vision Library (Open CV) to measure the ring radius of analytic wood disk digital images, and establish a regression equation of ring radius based on image geometric distortion correction. Here, a digital camera was used to photograph the stem disks’ tree rings to obtain digital images. The images were preprocessed with Open CV to measure the disk’s annual ring radius. The error correction model based on the least-square polynomial fitting method was established for digital image geometric distortion correction. Finally, a regression equation for tree ring radius based on the error correction model was established. Through the above steps, click the intersection point between the radius line and each ring to get the pixel distance from the ring to the pith, then the size of ring radius can be calculated by the regression equation of ring radius. The study’s method was used to measure the digital image of the Chinese fir stem disk and compare it with the actual value. The results showed that the maximum error of this method was 0.15 cm, the average error was 0.04 cm, and the average detection accuracy reached 99.34%, which met the requirements for measuring the tree ring radius by stem disk analysis. This method is simple, accurate, and suitable for coniferous and broad-leaved species, which allows researchers to analyze tree ring radius measurement, and is of great significance for analyzing the tree growth process.

Pengaruh Jangka Pendek Dan Jangka Panjang Variabel Makro Ekonomi Terhadap Ihsg Di Bursa Efek Indonesia Dengan Pendekatan Error Correction Model (ECM)

2019 ◽  
Vol 6 (1) ◽  
pp. 12-24
Author(s):  
Suryo Refli Ranto
Keyword(s):  
Error Correction ◽  
Error Correction Model ◽  
Correction Model

Penelitian ini bertujuan untuk menguji secara empiris pengaruh jangka pendek dan jangka panjang dari Inflasi, Jumlah Uang Berjalan, Kurs, Tingkat Bunga Bank Indonesia, Harga Minyak Dunia (WTI) dan Net Ekspor terhadap Indeks Harga Saham Gabungan (IHSG) dengan metode Error Correction Model (ECM) yang diolah dengan eviews 6.0. Selama periode pengamatan yaitu tahun 2000-2012 terjadi hubungan antara variabel makro dengan pergerakan IHSG di Bursa Efek Indonesia (BEI). Hasil uji ECM memperlihatkan Inflasi, kurs dan harga minyak dunia berpengaruh signifakan terhadap IHSG pada jangka pendek sedangkan pada jangka panjang variabel yang signifikan mempengaruhi IHSG adalah IHK, kurs, net ekspor dan harga minyak dunia.Kata kunci : IHSG, IHK, JUB, Kurs, tingkat Bunga Bank Indonesia (rSBI), Harga Minyak Dunia (WTI), Net Ekspor dan Error Correction Model (ECM) 

Corporate Taxes and Foreign Direct Investment: An Impact Analysis

2020 ◽  
Vol 5 (2) ◽  
pp. 28-43
Author(s):  
Onome Christopher Edo ◽  
Anthony Okafor ◽  
Akhigbodemhe Emmanuel Justice
Keyword(s):  
Foreign Direct Investment ◽  
Error Correction ◽  
Direct Investment ◽  
Impact Analysis ◽  
Negative Relationship ◽  
Value Added ◽  
Positive Association ◽  
Error Correction Model ◽  
Corporate Taxes ◽  
Correction Model

Objective – The purpose of this study is to investigate the effect of corporate taxes on the flow of Foreign Direct Investment (FDI) in Nigeria between 1983 and 2017. Methodology/Technique – This study adopts an ex-post facto research design. Secondary data was sourced from the World Bank Development Indicator, the Central Bank of Nigeria database, and the Federal Inland Revenue database. The research data was analyzed using the Error Correction Model (ECM). Findings – The coefficient of determination (R2) shows that approximately 77% of systematic changes in FDI are attributed to the combined effect of all of the explanatory variables used in this study. Specifically, the study concludes that Company Income Tax, Value Added Tax, and Custom and Excise Duties have a significant but negative relationship with FDI. In contrast, Tertiary Education Tax has a positive association with FDI. Further, Exchange Rate has a negative but significant relationship with FDI, Inflation had an insignificant but positive association with FDI, and GDP growth Rate and Trade Openness demonstrate a positive and significant association with FDI. Novelty – The findings of this study are distinguishable from previous studies, as it uncovers new evidence that higher Education Tax Rates influences FDI and emerging evidence on the effect of non-tax variables on FDI inflow. Type of Paper: Empirical. JEL Classification: E22, F21, H2, P33. Keywords: Corporate Taxes; Foreign Direct Investment; Error Correction Model; Nigeria; Non-Tax Variables. Reference to this paper should be made as follows: Edo, O.C; Okafor, A; Justice, A.E. 2020. Corporate Taxes and Foreign Direct Investment: An Impact Analysis, Acc. Fin. Review 5 (2): 28 – 43. https://doi.org/10.35609/afr.2020.5.2(1)

scholarly journals Tree-Ring Analysis of Intermediate Hawthorn (Crataegus media Bechst.) in NW Poland

Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Anna Cedro ◽  
Bernard Cedro
Keyword(s):  
Tree Ring ◽  
Tree Rings ◽  
Agricultural Landscape ◽  
Positive Influence ◽  
Dominant Factor ◽  
Incremental Growth ◽  
High Precipitation ◽  
Ring Analysis ◽  
Uncultivated Land ◽  
Nw Poland

Intermediate hawthorn (Crataegus × media Bechst.) is broadly distributed in Europe but very rarely examined by dendrochronologists. In NW Poland, it is one of three naturally occurring hawthorn species, growing mainly at forest margins, along roads, in mid-field woodlots, and on uncultivated land. Biocenotically, it is a very valuable species. This study aimed to determine the age of trees, tree-ring dynamics, and growth–climate relationship for intermediate hawthorn. Signature years were also determined. Samples for analysis were collected from 22 trees growing in a typical agricultural landscape in a monospecific mid-field woodlot comprised of several hundred specimens of various ages and forms (shrubs and trees). Using classic methods of dendrochronological dating, a 40-year long chronology spanning 1981–2020 was constructed. The radial growth rate of intermediate hawthorn is comparable to other tree species forming stands in NW Poland and equals 2.41 mm/year. Considerable intersubject variability is noted, from 1.48 to 4.44 mm/year. The chronology was also used for dendroclimatological analyses, including correlation and response function and signature years. Of the meteorological parameters analyzed, annual incremental growth in hawthorn is the most strongly shaped by precipitation totals from May to August of the current vegetation year: high rainfall favors the formation of wide tree-rings. Statistically significant growth–climate relationships were also obtained for winter months (December of the preceding vegetation year, January and February), for which period negative correlation and regression values are noted for air temperature and insolation. Furthermore, high precipitation, low-temperature and low insolation late in the preceding vegetation year (especially in August) make a positive influence on the condition of trees in the upcoming growing season. Signature year analysis clearly pointed to precipitation as the dominant factor in shaping tree-rings in the studied hawthorn population. As there are no dendrochronological papers concerning indigenous hawthorn species, future studies should be expanded to include diverse geographic locations and habitat conditions and should include all three species of hawthorn occurring in Poland.

Hypothesis testing with error correction models

2021 ◽  
pp. 1-9
Author(s):  
Patrick W. Kraft ◽  
Ellen M. Key ◽  
Matthew J. Lebo
Keyword(s):  
Hypothesis Testing ◽  
Error Correction ◽  
Null Hypothesis ◽  
Alternative Hypothesis ◽  
Correction Coefficient ◽  
Correction Model ◽  
Long Run ◽  
Independent Variable ◽  
The Right ◽  
General Error

Abstract Grant and Lebo (2016) and Keele et al. (2016) clarify the conditions under which the popular general error correction model (GECM) can be used and interpreted easily: In a bivariate GECM the data must be integrated in order to rely on the error correction coefficient, $\alpha _1^\ast$ , to test cointegration and measure the rate of error correction between a single exogenous x and a dependent variable, y. Here we demonstrate that even if the data are all integrated, the test on $\alpha _1^\ast$ is misunderstood when there is more than a single independent variable. The null hypothesis is that there is no cointegration between y and any x but the correct alternative hypothesis is that y is cointegrated with at least one—but not necessarily more than one—of the x's. A significant $\alpha _1^\ast$ can occur when some I(1) regressors are not cointegrated and the equation is not balanced. Thus, the correct limiting distributions of the right-hand-side long-run coefficients may be unknown. We use simulations to demonstrate the problem and then discuss implications for applied examples.

Sign in / Sign up

Export Citation Format

Share Document