scholarly journals Evapotranspiration simulated by CRITERIA and AquaCrop models in stony soils

2015 ◽  
Vol 10 (2) ◽  
pp. 67 ◽  
Author(s):  
Pasquale Campi ◽  
Francesca Modugno ◽  
Alejandra Navarro ◽  
Fausto Tomei ◽  
Giulia Villani ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Efficiency Index ◽  
Balance Model ◽  
Coefficient Of Determination ◽  
Wheat Crop ◽  
Area Index ◽  
Aquacrop Model ◽  
Daily Evapotranspiration ◽  
Daily Scale ◽  
The Impact

The performance of a water balance model is also based on the ability to correctly perform simulations in heterogeneous soils. The objective of this paper is to test CRITERIA and AquaCrop models in order to evaluate their suitability in estimating evapotranspiration at the field scale in two types of soil in the Mediterranean region: non-stony and stony soil. The first step of the work was to calibrate both models under the non-stony conditions. The models were calibrated by using observations on wheat crop (leaf area index or canopy cover, and phenological stages as a function of degree days) and pedo-climatic measurements. The second step consisted in the analysing the impact of the soil type on the models performances by comparing simulated and measured values. The outputs retained in the analysis were soil water content (at the daily scale) and crop evapotranspiration (at two time scales: daily and crop season). The model performances were evaluated through four statistical tests: normalised difference (D%) at the seasonal time scale; and relative root mean square error (RRMSE), efficiency index (EF), coefficient of determination (r<sup>2</sup>) at the daily scale. At the seasonal scale, values of D% were less than 15% in stony and on-stony soils, indicating a good performance attained by both models. At the daily scale, the RRMSE values (2) indicate the inadequacy of AquaCrop to simulate correctly daily evapotranspiration. The higher performance of CRITERIA model to simulate daily evapotranspiration in stony soils, is due to the soil submodel, which requires the percentage skeleton as an input, while AquaCrop model takes into account the presence of skeleton by reducing the soil volume.

scholarly journals Calibration and validation of the AquaCrop model for the soybean crop grown under different levels of irrigation in the Motopiba region, Brazil

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Vicente de Paulo Rodrigues da Silva ◽  
Roberta Araújo e Silva ◽  
Girlene Figueiredo Maciel ◽  
Célia Campos Braga ◽  
José Luiz Cabral da Silva Júnior ◽  
...  
Keyword(s):  
Model Performance ◽  
Absolute Error ◽  
Efficiency Index ◽  
Water Levels ◽  
Coefficient Of Determination ◽  
Yield Response ◽  
Statistical Parameters ◽  
Yield Data ◽  
Climate Conditions ◽  
Aquacrop Model

ABSTRACT: The water-driven AquaCrop model to simulate yield response has been calibrated and validated for soybean cultivated under different water levels irrigation in Matopiba region, Brazil. The crop was submitted to seven irrigation treatments during the dry season and a dry treatment in the rainy season. The model was parameterized and calibrated by using soybean yield data collected at field level. Model performance was evaluated by using the following statistical parameters: prediction error (Pe), Nash-Sutcliffe efficiency index (E), coefficient of determination (R2), mean absolute error (MAE), root mean square error normalized (RMSEN) and Willmott’s index (d). The statistical analyses of the AquaCrop model calibrated for the Matopiba region disclosed error acceptable for yield prediction of soybean grown under tropical climate conditions. Results also indicated that the C2 soybean cultivar is more resistant to water stress than the C1 soybean grown in the Matopiba region, Brazil. In the treatments when the crop was well supplied with water, at least in one phase, the yield was greater than those with drought stress at last in one phase.

Plant and soil influences on estimating biomass of wheat in plant breeding plots using field spectral radiometers

1996 ◽  
Vol 47 (7) ◽  
pp. 1017 ◽  
Author(s):  
SM Bellairs ◽  
NC Turner ◽  
PT Hick ◽  
RCG Smith
Keyword(s):  
Vegetation Index ◽  
Coefficient Of Determination ◽  
Wheat Crop ◽  
Growth Stages ◽  
Experimental Conditions ◽  
Area Index ◽  
Operational Conditions ◽  
Normalised Difference Vegetation Index ◽  
Early Vigour ◽  
Dark Soil

Field spectral radiometers were used to estimate the biomass of wheat at early growth stages, as wheat breeders require a rapid, non-destructive technique to rank wheat genotypes for early vigour. Under experimental conditions, good relationships were obtained between reflectance and biomass prior to the wheat crop achieving a green area index of 1.5. When used above different soil types, good results were achieved on very uniform dark and light soils under experimental conditions, but greater differentiation between plots differing in biomass was achieved on darker soils. Similarly, under operational conditions in wheat breeders' plots, the best results were achieved against a dark soil background. Structural differences between plants also influenced solar radiation reflectance. At the Merredin site with the dark soil background, where the best correlation between reflectance and biomass was achieved, the relationship was much stronger for the more uniform genotypes at the second stage of selection than for the more heterogeneous genotypes at the first stage of selection. On these plots, the vegetation spectral indices NDVI (normalised difference vegetation index) and TSAVI (transformed soil-adjusted vegetation index) had a coefficient of determination 90-95% as good as the best regression using two wavebands. To optimise the field spectroradiometry technique for estimating early biomass, it should be applied at a weed-free site, with a uniform dark soil background and on material that is relatively homogenous in structure. We conclude that, unless these precautions are taken, the technique will have limited utility in breeding programs.

scholarly journals Introduction of Variable Correlation for the Improved Retrieval of Crop Traits Using Canopy Reflectance Model Inversion

2019 ◽  
Vol 11 (22) ◽  
pp. 2681
Author(s):  
Asmaa Abdelbaki ◽  
Martin Schlerf ◽  
Wout Verhoef ◽  
Thomas Udelhoven
Keyword(s):  
Test Site ◽  
Coefficient Of Determination ◽  
Canopy Reflectance ◽  
Remotely Sensed Data ◽  
Biophysical Parameters ◽  
Area Index ◽  
Model Inversion ◽  
Ill Posed ◽  
The Impact

Look-up table (LUT)-based canopy reflectance models are considered robust methods to estimate vegetation attributes from remotely sensed data. However, the LUT inversion approach is sensitive to measurements and model uncertainties, which raise the ill-posed inverse problem. Therefore, regularization options are needed to mitigate this problem and reduce the uncertainties of estimates. In this study, we introduce a new method to regularize the LUT inversion approach to improve the accuracy of biophysical parameters (leaf area index (LAI) and fractional vegetation cover (fCover)). This was achieved by incorporating known variable correlations that existed at the test site into the LUT approach to correlate the model variables of the Soil–Leaf–Canopy (SLC) model using the Cholesky decomposition algorithm. The retrievals of 27 potato plots obtained from the regularized LUT (LUTreg) were compared with the standard LUT (LUTstd), which did not consider variable correlations. Different solutions from both types of LUTs (LUTreg and LUTstd) were utilized to improve the quality of the model outputs. Results indicate that the present method improved the accuracy of LAI estimation, with the coefficient of determination R2 = 0.74 and normalized root-mean-square error NRMSE = 24.45% in LUTreg, compared with R2 = 0.71 and NRMSE = 25.57% in LUTstd. In addition, the variability of LAI decreased in LUTreg (5.10) compared with that in LUTstd (12.10). Hence, our results give new insight into the impact of adding the correlation between variables to the LUT inversion approach to improve the accuracy of estimations. In this study, only two correlated variables (LAI and fCover) were examined; in subsequent studies, the full correlation matrix based on the Cholesky algorithm should be explored.

The Effect of Investments and Risk Based Capital (RBC) of Tabarru Funds on Company (Case Study of Sharia Insurance in Indonesia for 2014-2019)

2020 ◽  
Vol 8 (1) ◽  
pp. 87-97
Author(s):  
Nana Diana ◽  
Tati Apriani
Keyword(s):  
Life Insurance ◽  
Statistical Tests ◽  
Linear Regression Analysis ◽  
Sampling Technique ◽  
Multiple Linear Regression Analysis ◽  
Insurance Companies ◽  
Coefficient Of Determination ◽  
Verification Method ◽  
Investment Returns ◽  
The Government

This study aims to examine the influence of investment returns and Risk Based Capital (RBC) Tabarru Funds to the profit of sharia life insurance in Indonesia from 2014-2019. This study The type of this research is quantitative research with descriptive verification as a method. This research method uses descriptive verification method with quantitative approach. The data used in this study were sourced from the financial statements of Islamic life insurance companies in Indonesia for the 2014-2019 period. Then the data obtained were analyzed using multiple linear regression analysis and hypothesis testing consisting of t test and f test with the help of SPSS 21 software. The sampling technique uses non probability sampling with purposive sampling technique. Based on the results of the study it can be seen that the development of investment returns on Sharia Life Insurance in Indonesia has fluctuated and even suffered losses. While the development of Risk Based Capital (RBC) has increased and decreased but overall above 120% as determined by the government. Likewise, the profits earned in each year fluctuate. The results of statistical tests show that investment results partially have a positive effect on profit and Risk Based Capital (RBC) of Tabarru funds partially has a negative effect on profit. Simultaneously investment return and Risk Based Capital (RBC) affect on profit. In addition, the results of the coefficient of determination (R2) were obtained which obtained a value of 81%. This shows that the variable investment returns and Risk Based Capital (RBC) can affect earnings by 81% and the remaining 19% is influenced by other variables not used in this study.

An influence of social isolation on the level of physical activity as well as on well-being and mental state of people during the coronavirus COVID-19 pandemic

2019 ◽  
Vol 129 (4) ◽  
pp. 127-131
Author(s):  
Agnieszka Parfin ◽  
Krystian Wdowiak ◽  
Marzena Furtak-Niczyporuk ◽  
Jolanta Herda
Keyword(s):  
Physical Activity ◽  
Social Isolation ◽  
Small Sample Size ◽  
Statistical Tests ◽  
Population Group ◽  
Well Being ◽  
Small Sample ◽  
Subjective Well Being ◽  
Tract Infections ◽  
The Impact

AbstractIntroduction. The COVID-19 is the name of an infectious disease caused by a new strain of coronavirus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2). It was first diagnosed in December 2019 in patients in Wuhan City, Hubei Province, China. The symptoms are dominated by features of respiratory tract infections, in some patients with a very severe course leading to respiratory failure and, in extreme cases to death. Due to the spread of the infection worldwide, the WHO declared a pandemic in March 2020.Aim. An investigation of the impact of social isolation introduced due to the coronavirus pandemic on selected aspects of life. The researchers focused on observing changes in habits related to physical activity and their connections with people’s subjective well-being and emotional state.Material and methods. The study was carried out within the international project of the group „IRG on COVID and exercise”. The research tool was a standardized questionnaire.Results. Based on the data collected and the analysis of the percentage results, it can be observed that the overwhelming majority of people taking up physical activity reported a better mood during the pandemic. However, statistical tests do not confirm these relationships due to the small sample size.Conclusions. Isolation favours physical activity. Future, in-depth studies, by enlarging the population group, are necessary to confirm the above observations.

The Impact of Business Mentoring on Micro, Small, Medium Enterprises Performance

2017 ◽  
Vol 1 (1) ◽  
pp. 31-37
Author(s):  
Mohammad Adrian ◽  
Hendrati Dwi Mulyaningsih ◽  
Santi Rahmawati
Keyword(s):  
Quantitative Research ◽  
Causal Analysis ◽  
Coefficient Of Determination ◽  
Mentoring Program ◽  
Simple Regression Analysis ◽  
Small Medium Enterprises ◽  
Medium Enterprises ◽  
The Impact ◽  
Necessity Entrepreneur ◽  
Simple Regression

This reasearch is conducted on MMSME (Micro Small Medium Enterprises) that are participated in the MMSME Syari’ah Mentoring Program by Academicians and Practitioners (PUSPA) organized by Bank Indonesia in Bandung. MMSME who participated in PUSPA program 2016 is MMSME that included in necessity entrepreneur where MMSME operated just to fullfil the life necessities. The purpose of this reasearch was to investigate the influence of the business mentoring on the MMSME performance in PUSPA program 2016. Researcher used quantitative research method. Data were analyzed using simple regression analysis and descriptive-causal analysis. The result showed that business mentoring affect the performance of MMSME that participated in PUSPA Program 2016. Based on the calculation, coefficient of determination (R2) can be seen the influence of business mentoring variable (X) on the performance (Y) is 74%. While the remaining 26% is influenced by other factors such as entrepreneurship competence and human resources.

The Impact of Entrepreneurial Behavior on Sales Volume

2017 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Adjeng Tiara Eltari ◽  
Hendrati Dwi Mulyaningsih
Keyword(s):  
Quantitative Research ◽  
Coefficient Of Determination ◽  
Sales Volume ◽  
Entrepreneurial Behavior ◽  
Street Vendors ◽  
Quantitative Research Methods ◽  
Entrepreneurial Behaviour ◽  
Full Calculation ◽  
Almost All ◽  
The Impact

This research was conducted at the Culinary Hawkers that located on Highway Sukapura, Dayeuhkolot, Bandung. This study examines the Entrepreneurial behaviour which resulted in increased sales volumes. Almost all Culinary Hawkers on Highway Sukapura doesn’t yet have the entrepreneurial behavior in accordance with the characteristics - traits mentioned by Suryana, Confident, Own initiative, Have achievement motive, Having leadership, and Dare to take risks with the full calculation. The purpose of this study was to investigate the influence of entrepreneurial behavior to the merchant's sales volume culinary pavement on Highway Sukapura, Dayeuhkolot, Bandung.Researchers used quantitative research methods. The population in this study was 63 Merchants Culinary Street on Highway Sukapura. Samples are 63 street vendors in JalanSukapura. Data were analyzed using simple regression analysis.The results showed that entrepreneurial behavior affect the sales volume of culinary street traders in Highway Sukapura. Based on the calculation coefficient of determination (R2) can be seen the effect of entrepreneurial behavior variables (X) on sales volume (Y) is approximately 94%. While the remaining 6% are influenced by other factors such as competence, performance, and motivation.

THE IMPACT OF BUSINESS MENTORING ON MICRO, SMALL, MEDIUM ENTERPRISES PERFORMANCE

2018 ◽  
Vol 1 (1) ◽  
pp. 7
Author(s):  
Mohammad Adrian ◽  
Santi Rahmawati
Keyword(s):  
Research Method ◽  
Quantitative Research ◽  
Coefficient Of Determination ◽  
Mentoring Program ◽  
Simple Regression Analysis ◽  
Small Medium Enterprises ◽  
Medium Enterprises ◽  
The Impact ◽  
Necessity Entrepreneur ◽  
Simple Regression

This reasearch is conducted on MSME (Micro Small Medium Enterprises) that are participated in the MSME Syari’ah Mentoring Program by Academition and Practitioners (PUSPA) organized by Bank Indonesia in Bandung. MSME who participated in PUSPA program 2016 is MSME that included in necessity entrepreneur where MSME operated just to fullfil the life necessities.The purpose of this reasearch was to investigate the influence of the business mentoring on the MSME performance in PUSPA program 2016.Researcher used quantitative research method. Data were analyzed using simple regression analysis and descriptive-causal analysis.The result showed that business mentoring affect the performance of MSME that participated in PUSPA Program 2016. Based on the calculation, coefficient of determination (R2) can be seen the influence of business mentoring variable (X) on the performance (Y) is 74%. While the remaining 26% is influenced by other factors such as entrepreneurship competence and human resources.  

تأثير الاستثمار الاجنبي المباشر في القيمة السوقية للشركة (دراسة تطبيقية في شركة بترو جانيا الصينية في عقود التراخيص النفطية للجولة الاولى والثانية في الحقول النفطية في العراق للمدة من 2017-2010)

2020 ◽  
Vol 2020 (66) ◽  
pp. 65-85
Author(s):  
هيثم عبد النبي موسى ◽  
أ .د حيدر نعمة غالي الفريجي
Keyword(s):  
Foreign Direct Investment ◽  
Stock Prices ◽  
Return On Investment ◽  
Direct Investment ◽  
Inverse Correlation ◽  
Market Value ◽  
Political Stability ◽  
Coefficient Of Determination ◽  
Independent Variable ◽  
The Impact

This study dealt with the effect of foreign direct investment on the market value of the company during the period of time (2010-2017). This issue was studied through a sample of oil fields in southern Iraq in which the company operates within the first and second licensing contracts rounds and according to the circumstances and variables of the investment environment as it is. Although this investment often achieves high returns, it is also characterized by a high degree of risk and for the purpose of evaluating the impact of foreign direct investment on the market value of the company's stock prices for the period (2010-2017). The statistical scale (T-TEST) was used to indicate the significance of the correlation hypotheses. Between the return on investment as the independent variable and the market value as the dependent variable, and the use of the coefficient of determination (R2) that measures the effect of the independent variable (foreign direct investment) on the dependent variable (market value) and the F-Test to demonstrate acceptance or rejection of the hypothesis of the return on investing in the market value of the oil company, and if the company achieves a high return in foreign direct investment, the market value of it will be affected positively. The study was based on a set of goals, including determining the attractiveness of Iraq to foreign investments, especially the oil sector, and the study reached a number of conclusions, the most prominent of which is the existence of a strong inverse correlation between the return on investment and the market value of the company. And the existence of a slight impact of the return on investment on the market value of the company, and the study reached a number of recommendations, the most important of which is activating the investment climate through political stability and the clarity and stability of laws and legislation regulating investment, which is one of the most important factors affecting the investment decision.

scholarly journals Assessing the Impact of Attendance Modality on the Learning Performance of a Course on Machines and Mechanisms Theory

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 558
Author(s):  
David Valiente ◽  
Héctor Campello-Vicente ◽  
Emilio Velasco-Sánchez ◽  
Fernando Rodríguez-Mas ◽  
Nuria Campillo-Davo
Keyword(s):  
Statistical Tests ◽  
Group Testing ◽  
Test Group ◽  
Historical Record ◽  
Team Work ◽  
University Education ◽  
Learning Performance ◽  
Control Group ◽  
Face To Face ◽  
The Impact

University education approaches related to the field of science, technology, engineering and mathematics (STEM), have generally particularized on teaching activity and learning programs which are commonly understood as reoriented lessons that fuse theoretic concepts interweaved with practical activities. In this context, team work has been widely acknowledged as a means to conduct practical and hands-on lessons, and has been revealed to be successful in the achievement of exercise resolution and design tasks. Besides this, methodologies sustained by ICT resources such as online or blended approaches, have also reported numerous benefits for students’ active learning. However, such benefits have to be fully validated within the particular teaching context, which may facilitate student achievement to a greater or lesser extent. In this work, we analyze the impact of attendance modalities on the learning performance of a STEM-related course on “Machines and Mechanisms Theory”, in which practical lessons are tackled through a team work approach. The validity of the results is reinforced by group testing and statistical tests with a sample of 128 participants. Students were arranged in a test group (online attendance) and in a control group (face-to-face attendance) to proceed with team work during the practical lessons. Thus, the efficacy of distance and in situ methodologies is compared. Moreover, additional variables have also been compared according to the historical record of the course, in regards to previous academic years. Finally, students’ insights about the collaborative side of this program, self-knowledge and satisfaction with the proposal have also been reported by a custom questionnaire. The results demonstrate greater performance and satisfaction amongst participants in the face-to-face modality. Such a modality is prooven to be statistically significant for the final achievement of students in detriment to online attendance.

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