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1

Analyzing rear-end crash severity for a mountainous expressway in China via a classification and regression tree with random forest approach

Wang Yonggang, Luo Xianyu

Archives of Civil Engineering

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2021

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Vol. 67, nr 4

591--604

EN

To understand the contributory factors to rear-end accident severity on mountainous expressways, a total of 1039 rear-end accidents, occurring on G5 Jingkun Expressway from Hechizhai to Qipanguan in Shaanxi, China over the period of 2012 to 2017, were collected, and a non-parametric Classification and Regression Tree (CART) model was used to explore the relationship between severity outcomes and driver factors, vehicle characteristics, roadway geometry and environmental conditions. Then the random forest model was introduced to examine the accuracy of variable selection and rank their importance. The results show that driver’s risky driving behaviours, vehicle type, radius of curve, angle of deflection, type of vertical curve, time, season, and weather are significantly associated with rear-end accident severity. Speeding and driving while drunk and fatigued are more prone to result in severe consequences for such accidents and driving while fatigued is found to have the highest fatality probability, especially during the night period (18:00-24:00). The involvement of heavy trucks increases the injury probability significantly, but decreases the fatality probability. In addition, adverse weather and sharp curve with radius less than 1000 m are the most risk combination of factors. These findings can help agencies more effectively establish stricter regulations, adopt technical measures and strengthen safety education to ensure driver's driving safety on mountainous expressways for today and tomorrow.

2

A comparison of advanced computational models and experimental techniques in predicting blast induced ground vibration in open pit coal mine

Nguyen Hoang, Bui Xuan Nam, Moayedi Hossein

Acta Geophysica

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2019

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Vol. 67, no. 4

1025--1037

EN

Green mining is an essential requirement for the development of the mining industry. Of the operations in mining technology, blasting is one of the operations that signifcantly affect the environment, especially ground vibration. In this paper, four artificial intelligence (AI) models including artificial neural network (ANN), k-nearest neighbor (KNN), support vector machine (SVM), and classification and regression tree (CART) were developed as the advanced computational models for estimating blast-induced ground vibration in a case study of Vietnam. Some empirical techniques were applied and developed to predict ground vibration and compared with the four AI models as well. For this research, 68 events of blasting were collected; 80% of the whole datasets were used to build the mentioned models, and the rest 20% were used for testing/checking the models’ performances. Mean absolute error (MAE), determination coefficient (R2 ), and root-mean-square error (RMSE) were used as the standards to evaluate the quality of the models in this study. The results indicated that the advanced computational models were much better than empirical techniques in estimating blast-induced ground vibration in the present study. The ANN model (2-6-8-6-1) was introduced as the most superior model for predicting ground vibration with an RMSE of 0.508, R2 of 0.981 and MAE of 0.405 on the testing dataset. The SVM, CART, and KNN models provided poorer performance with an RMSE of 1.192, 2.820, 1.878; R2 of 0.886, 0.618, 0.737; and MAE of 0.659, 1.631, 0.762, respectively.

3

Modeling the 2D space of emotions based on the poincare plot of heart rate variability signal

Moharreri S., Dabanloo N. J., Maghooli K.

Biocybernetics and Biomedical Engineering

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2018

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Vol. 38, no. 4

794--809

EN

Emotions mean accepting, understanding, and recognizing something with one's senses. The physiological signals generated from the internal organs of the body can objectively and realistically reflect changes in real-time human emotions and monitor the state of the body. In this study, the two-dimensional space-based emotion model was introduced on the basis of Poincare's two-dimensional plot of the signal of heart rate variability. Four main colors of psychology, blue, red, green, and yellow were used as a stimulant of emotion, and the ECG signals from 70 female students were recorded. Using extracted features of Poincare plot and heart rate asymmetry, two tree based models estimated the levels of arousal and valence with 0.05 mean square errors, determined an appropriate estimation of these two parameters of emotion. In the next stage of the study, four different emotions mean pleasure, anger, joy, and sadness, were classified using IF-THEN rules with the accuracy of 95.71%. The results show the color red is associated with more excitement and anger, while green has small anxiety. So, this system provides a measure for numerical comparison of mental states and makes it possible to model emotions for interacting with the computer and control mental states independently of the pharmaceutical methods.

4

Application of regression trees in the analysis of electricity load

Gładysz B., Kuchta D.

Badania Operacyjne i Decyzje

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2008

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nr 4

19-28

EN

In the paper electricity load analysis was performed for a power region in Poland. Identifying the factors that influence the electricity demand and determining the nature of the influence is a crucial element of an effective energy management. In order to analyse the electricity load level the CART (Classification and Regression Tree) method has been used. The data for the analysis are hourly observations of the electricity load and weather throughout one year period. Two categories of factors were taken as predictor variables, on which the demand for the electricity load depends: variables describing weather and variables representing structure days in a year. An analysis of the errors of the presented models was carried out.

PL

W artykule zbadano wpływ warunków atmosferycznych na poziom obciążenia systemu elektroenergetycznego. Identyfikacja czynników warunkujących wielkość popytu na energię elektryczną jest podstawowym elementem systemu zarządzania energią elektryczną. W badaniach zastosowano metodę k-średnich oraz technikę drzew klasyfikacyjnych i regresyjnych. W pierwszym etapie badań metodą k-średnich wyróżniono jednorodne - z uwagi na obciążenie systemu elektroenergetycznego - grupy godzin w skali doby. Dla każdej z grup dla wybranej godziny (reprezentanta) zbudowano drzewo regresyjne, przyjmując jako czynniki dane meteorologiczne oraz typ dnia w skali roku. Przeprowadzona analiza pokazała, że czynnikami warunkującymi poziom obciążenia systemu energetycznego są: temperatura, punkt rosy, wilgotność oraz rodzaj opadów. Informacja o rodzaju oraz wartościach progowych tych czynników meteorologicznych może zostać wykorzystana w procesie prognozowania poziomu obciążenia systemu elektroenergetycznego i tym samym przyczynić się do poprawy efektywności procesów zarządzania energią. Przeprowadzono analizę błędów skonstruowanych drzew regresyjnych.

5

Dipolar regression trees in survival analysis

Krętowska M.

Biocybernetics and Biomedical Engineering

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2004

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Vol. 24, no. 3

25-33

EN

In this paper a new method for induction of multivariate regression trees is presented. The technique is designed for the survival time prediction and based on given data. The proposed method aims at identification of subgroups of patients with homogenous survival experience i.e. homogenous response for a given treatment. The method allows using information from censored cases for which the exact failure time is unknown. An appropriate degree of generalization is obtained by using a pruning algorithm, which is based on rank correlation coefficient D.