Determination of Climatic Conditions Related to Precipitation Anomalies in the Tropical Andes by Means of the Random Forest Algorithm and Novel Climate Indices

Author(s):  
Mario Córdova ◽  
Johanna Orellana‐Alvear ◽  
Rütger Rollenbeck ◽  
Rolando Célleri
Author(s):  
Charity Ojochogwu Egbunu ◽  
Matthew Tunde Ogedengbe ◽  
Terungwa Simon Yange ◽  
Terlumun Gbaden ◽  
Malik Adeiza Rufai ◽  
...  

With the explosive growth in the world’s population which has little or no corresponding rise in the food production, food insecurity has become eminent, and hence, the need to seek for opportunities to increase food production in order to cater for this population is paramount. The second goal of the Sustainable Development Goals (SDGs) (i.e., ending hunger, achieving food security and improved nutrition, and promoting sustainable agriculture) set by the United Nations (UN) for the year 2030 clearly acknowledged this fact. Improving food production cannot be achieved using the obsolete conventional methods of agriculture by our farmers; hence, this study focuses on developing a model for predicting climatic conditions with a view to reducing their negative impact, and boosting the yield of crop. Temperature, wind, humidity and rainfall were considered as the effect of these factors is more devastating in Nigeria as compared to sun light which is always in abundance. We implemented random forest algorithm using Python programming language to predict the aforementioned climate parameters. The data used was gotten from the Nigerian Meteorological (NiMet) Agency, Lokoja, Kogi State between 1988 and 2018. The result shows that random forest algorithm is effective in climate prediction as the accuracy from the model based on the climatic factors considered was 94.64%. With this, farmers would be able to plan ahead to prevent the impact of the fluctuations in these climatic factors; thus, the yield of crops would be increased. This would dwarf the negative impact of food insecurity to the populace.


2020 ◽  
Vol 222 (2) ◽  
pp. 978-988
Author(s):  
Yury Meshalkin ◽  
Anuar Shakirov ◽  
Evgeniy Popov ◽  
Dmitry Koroteev ◽  
Irina Gurbatova

SUMMARY Rock thermal conductivity is an essential input parameter for enhanced oil recovery methods design and optimization and for basin and petroleum system modelling. Absence of any effective technique for direct in situ measurements of rock thermal conductivity makes the development of well-log based methods for rock thermal conductivity determination highly desirable. A major part of the existing problem solutions is regression model-based approaches. Literature review revealed that there are only several studies performed to assess the applicability of neural network-based algorithms to predict rock thermal conductivity from well-logging data. In this research, we aim to define the most effective machine-learning algorithms for well-log based determination of rock thermal conductivity. Well-logging data acquired at a heavy oil reservoir together with results of thermal logging on cores extracted from two wells were the basis for our research. Eight different regression models were developed and tested to predict vertical variations of rock conductivity from well-logging data. Additionally, rock thermal conductivity was determined based on Lichtenecker–Asaad model. Comparison study of regression-based and theoretical-based approaches was performed. Among considered machine learning techniques Random Forest algorithm was found to be the most accurate at well-log based determination of rock thermal conductivity. From a comparison of the thermal conductivity—depth profile predicted from well-logging data with the experimental data, and it can be concluded that thermal conductivity can be determined with a total relative error of 12.54 per cent. The obtained results prove that rock thermal conductivity can be inferred from well-logging data for wells that are drilled in a similar geological setting based on the Random Forest algorithm with an accuracy sufficient for industrial needs.


Author(s):  
Yessi Yunitasari ◽  
Aina Musdholifah ◽  
Anny Kartika Sari

Twitter is one of the social medias that are widely used at the moment. Tweet conversations can be classified according to their sentiments. The existence of sarcasm contained in a tweet sometimes causes incorrect determination of the tweet’s sentiment because sarcasm is difficult to analyze automatically, even by humans. Hence, sarcasm detection needs to be conducted, which is expected to improve the results of sentiment analysis. The effect of sarcasm detection on sentiment analysis can be seen in terms of accuracy, precision and recall. In this paper, detection of sarcasm is applied to Indonesian tweets. The feature extraction of sarcasm detection uses unigram and 4 Boazizi feature sets which consist of sentiment-relate features, punctuation-relate features, lexical and syntactic features, and top word features. Detection of sarcasm uses the Random Forest algorithm. The feature extraction of sentiment analysis uses TF-IDF, while the classification uses Naïve Bayes algorithm. The evaluation shows that sentiment analysis with sarcasm detection improves the  accuracy of sentiment analysis about 5.49%. The accuracy of the model is 80.4%, while the precision is 83.2%, and the recall is 91.3%.


2021 ◽  
Vol 5 (2) ◽  
pp. 369-378
Author(s):  
Eka Pandu Cynthia ◽  
M. Afif Rizky A. ◽  
Alwis Nazir ◽  
Fadhilah Syafria

This paper explains the use of the Random Forest Algorithm to investigate the Case of Acute Coronary Syndrome (ACS). The objectives of this study are to review the evaluation of the use of data science techniques and machine learning algorithms in creating a model that can classify whether or not cases of acute coronary syndrome occur. The research method used in this study refers to the IBM Foundational Methodology for Data Science, include: i) inventorying dataset about ACS, ii) preprocessing for the data into four sub-processes, i.e. requirements, collection, understanding, and preparation, iii) determination of RFA, i.e. the "n" of the tree which will form a forest and forming trees from the random forest that has been created, and iv) determination of the model evaluation and result in analysis based on Python programming language. Based on the experiments that the learning have been conducted using a random forest machine-learning algorithm with an n-estimator value of 100 and each tree's depth (max depth) with a value of 4, learning scenarios of 70:30, 80:20, and 90:10 on 444 cases of acute coronary syndrome data. The results show that the 70:30 scenario model has the best results, with an accuracy value of 83.45%, a precision value of 85%, and a recall value of 92.4%. Conclusions obtained from the experiment results were evaluated with various statistical metrics (accuracy, precision, and recall) in each learning scenario on 444 cases of acute coronary syndrome data with a cross-validation value of 10 fold.


2019 ◽  
Vol 49 (4) ◽  
pp. 101-105 ◽  
Author(s):  
G. M. Shkyratova ◽  
B. Z. Bazaron ◽  
T. N. Khamiruev ◽  
S. M. Dashinimaev

The seasonal changes in the skin thickness and structure of the horses’ coat, as signs of adaptation to environmental factors, were studied. The experiment was carried out with the livestock kept in a herd using winter-grazing technology without additional feedings in the climatic conditions of the Trans-Baikal Territory. The objects of the research were adult mares of Zabaikalsky breed of horses of the same age, class and fatness. The studies were carried out in the middle of each season (May, July, October, February). The length of the coat was measured with a caliper, the coat itself with the determination of the ratio of hair (fl uffy hair, heterotype hair and coarse hair) and the thickness of the skin fold were measured in accordance with the approved methodological recommendations. The minimum skin thickness in winter was detected in mares on the back and shoulder blade – 4.3 and 4.4 mm, the maximum – on the side and thigh – 4.5 4.6 mm. When compared with the summer period, the increase on the side was 0.8 mm, whereas on the back, shoulder blade and thigh – 0.4 mm (p ≤ 0,001). In spring, thickening of the skin was noted within 0.1-0.3 mm in the same topographic areas, compared to autumn. The quantitative indicators of the coat changed depending on the season of the year. In winter, the coat contained more fl uffy hair (23.10%), and less coarse hair (68.24%), in summer there was a lower content of fl uffy hair (4.33%), but more coarse hair (94.01%.) Sharp seasonal changes were noted with regard to the length of the hair. The longest hair was found in winter and spring – 4.96 and 4.26 cm, whereas the shortest – in summer and autumn – 0.94 and 1.90 cm, respectively.


Author(s):  
A.E. Semenov

The method of pedestrian navigation in the cities illustrated by the example of Saint-Petersburg was investigated. The factors influencing people when they choose a route for their walk were determined. Based on acquired factors corresponding data was collected and used to develop model determining attractiveness of a street in the city using Random Forest algorithm. The results obtained shows that routes provided by the method are 14% more attractive and just 6% longer compared with the shortest ones.


Sign in / Sign up

Export Citation Format

Share Document