In central-western Argentina, an Early Paleozoic belt including mafic-ultramafic bodies and marine metasedimentary rocks occurs along the western margin of the Precordillera and in the eastern ...Frontal Cordillera. In this paper, we present the analysis of aeromagnetic data and its processing focused on mapping geological limits, structures and the relation at depth of the southern Precordillera. With this main objective were applied filtering algorithms, reduction to the pole, tilt derivative, analytic signal, and particularly, the use of Improved Logistic Function (IL) as a new method of edge detection, in combination with the inversion map obtained from the Magnetization Vector Inversion (MVI) method. The results allow us to describe at depth the main trend of the Southern Precordillera Mafic Ultramafic Belt as two separated bocks, one in Peñasco and another in Cerro (Co.) Cortaderas, passing through Cerro (Co.) Pozos with a possible NNE-SSW direction. The combination of this techniques also can be used as prospecting guide to Pb–Zn–Ag vein deposits and High sulfidation Au-Epitermal deposits.
•Determination of the Precordillera Mafic-Ultramafic Belt.•Linkage of maximum susceptibility, IL filter, outcrops of Mafic Ultramafic rocks and structural lineaments.•Magnetic Susceptibility 3D Model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The result of single-ended traveling wave fault location method based on wavelet transform will be affected by false wavelet transform modulus maxima (WTMM) points. In this paper, fault ...distance/impedance information contained in the wave front of the traveling wave is analyzed first. Then, the fitting method based on generalized logistic function is proposed to extract the fault information. Based on the fitting results, a predictor-corrector fault location method is proposed, which includes the following content. First, the fitting coefficients of the zero-mode fault current wave front are used to estimate fault distance and fault impedance interval. Second, the arrival time of the line-mode fault current reflected wave can be calibrated and the distance calculation formula can be selected according to the fault distance estimation interval. Last, the fault distance will be corrected to be within the fault distance estimation interval, if the first reflected wave is undetected. A model of ±400 kV DC transmission project is built in PSCAD/EMTDC. The simulation results show that the fitting coefficients can directly correspond to fault distance/impedance. The proposed method can effectively eliminate the influence of the false WTMM points, and give the accurate fault location results as well as fault impedance interval.
The path-following (PF) problem of an autonomous underwater vehicle (AUV) is studied, in which the path convergence is viewed as the main task while the speed profile is also taken into consideration ...as a secondary task. To accommodate the prioritized PF tasks, a novel multiobjective model predictive control (MPC) (MOMPC) framework is developed. Two methods, namely, weighted sum (WS) and lexicographic ordering, are investigated for solving the MOMPC PF problem. A logistic function is proposed for the WS method in an attempt to automatically select the appropriate weights. The Pontryagin minimum principle is subsequently applied for the WS-MOMPC implementation. The implicit relation between the two methods is shown, and the convergence of the solution with the MOMPC PF control algorithms is analyzed. Simulation studies on the Saab SeaEye Falcon AUV demonstrate the effectiveness of the proposed MOMPC PF control.
One of the dominant species of green algae growing along the Mediterranean coast of Egypt is Ulva lactuca. Pretreatment can have a major effect on biogas production because hydrolysis of the algae ...cell wall structure is a rate-limiting stage in the anaerobic digestion (AD) process. The use of ozone, a new pretreatment, to boost biogas production from the green algae Ulva lactuca was investigated in this study. Ozonation at various dosages was used in contrast to untreated biomass, and the effect on the performance of subsequent mesophilic AD using two separate inoculums (cow manure and activated sludge) was examined. The findings indicated that, in different studies, ozonation pretreatment showed a substantial increase in biogas yield relative to untreated algae. With an ozone dose of 249 mg O3 g–1 VS algal for Ulva lactuca, the highest biogas output (498.75 mL/g VS) was achieved using cow manure inoculum. The evaluation of FTIR, TGA, SEM, and XRD revealed the impact of O3 on the structure of the algal cell wall and integrity breakage, which was thus established as the main contributor to improving the biogas production.
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•An approach associating articulation index (AI) well estimates automatic speech recognition (ASR) accuracy for mandarin affected by noise.•The model associating AI is an effective tool to evaluate ...the characteristics, e.g. accuracy and robustness, of an ASR system.•The model indicates the similarity between human and machine speech recognition and could guide noise control measures for improving ASR accuracy.
The automatic speech recognition (ASR) technology has become one of the fast-growing engineering technologies. The ASR accuracy is often reduced by environmental interference noise. Many studies attempted to improve the ASR word accuracy in noisy backgrounds, but few were concerned about estimating the influence of noise on the word accuracy of ASR systems. This study investigated the effect of stationary noise on the word accuracy for mandarin of two ASR systems (i.e., the Baidu Cloud and Microsoft Azure). We selected the speech material from an open Mandarin speech database. The interference noise contained pink noise, white noise, random noise with equivalent power spectrum to the average power spectrum of mandarin, band-stop filtered noise and several typical household appliances noise (i.e., hairdryer, range hood, blender and water purifier). The signal-to-noise ratios (SNRs) were set to the range −12–3 dB. The Azure ASR system was less affected by noise and tended to have a higher word accuracy under the same noise condition than the Baidu ASR system. We proposed an approach to associate the articulation index (AI) of interference noise with the speech recognition accuracy of ASR systems. A three-parameter logistic model could be established for a specific ASR system, and each parameter is linearly dependent on the AI of interference noise. The performance of ASR systems under different stationary noise conditions could be quantitatively assessed and compared through the approach. Different models should be established for different versions of the ASR systems through this AI-associating approach since the parameters of one model are only applicable to one particular version of an ASR system.
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•Expansion and senescence of wheat LAI were quantified using first order derivative of logistic function.•New model added dynamics of tillering and leaf area of tiller cohorts.•Expansion rate of ...winter wheat LAI responded linearly to soil water stress.•Senescence rate of winter wheat LAI responded non-linearly to soil water stress.•RMSE simulated by the new LAI model was 47.89% lower than that of the original CERES-Wheat model.
Current crop models usually need a lot of input information to simulate crop leaf area index and have relatively large simulation errors under soil water stress, which need to be improved. In this study, based on experiments conducted in glass soil columns and field under rainout shelters in four years (2012-2016) in Yangling, Shaanxi Province in China, we attempted to establish a dynamic model for simulating leaf expansion and senescence of winter wheat under soil water stress. First, a temperature response function was established with four cardinal temperatures (base temperature, lower optimum temperature, higher optimum temperature, and maximum temperature). Then two soil water stress functions were established to quantify the effect of soil water stress on the processes of leaf expansion and leaf senescence of main stem per plant. The first order derivative of a logistic function was then modified with the temperature and soil water stress response function and was used to simulate the daily rate of leaf area expansion and senescence of main stem. The parameters of the new model were estimated using the Solver add-in in MS Excel and then validated based on the data of soil column experiments in 2014-2015 growing season. Then the new model was evaluated with another dataset of column experiments conducted in 2015-2016. Furthermore, the influence of soil water stress on wheat tillering was included in the new model based on open field experiments in 2012-2013 growing season. Then, the new leaf area index (LAI) simulation model was further verified with the data of open field experiments under rainout shelter (2013-2014) and rainfed condition (2004-2005, 2005-2006, and 2008-2009) in different sites. A comparison was conducted between new LAI model and the original LAI module of CERES-Wheat. The results showed that the leaf expansion rate was not affected when the relative soil water availability was greater than 0.7; water stress inhibited the leaf expansion when relative soil water availability was between 0.2 and 0.7; leaves withered and yellowed when relative soil water availability was less than 0.2. The overall average root mean square error (RMSE) and residual accumulation coefficient (CRM) were 9.78 cm2 plant−1, -0.03, and 6.51 cm2 plant−1; 0.05 for model calibration and validation, respectively. The RMSE of LAI decreased by an average of 47.89% compared with the original LAI module of CERES-Wheat. The results of this study can help to improve the current CERES-Wheat model for model applications in the arid and semi-arid regions of China.
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Coronavirus disease 2019 outbreak has spread as a pandemic since the end of year 2019. This situation has been causing a lot of problems of human beings such as economic problems, health problems. ...The forecasting of the number of infectious people is required by the authorities of all
countries including Southeast Asian countries to make a decision and control the outbreak. This research is to investigate the suitable forecasting model for the number of infectious people in Southeast Asian countries. A comparison of forecasting models between logistic growth curve which
is symmetric and Gompertz growth curve which is asymmetric based on the maximum of Coefficient of Determination and the minimum of Root Mean Squared Percentage Error is also proposed. The estimation of parameters of the forecasting models is evaluated by the least square method. In addition,
spreading of the outbreak is estimated by the derivative of the number of cumulative cases. The findings show that Gompertz growth curve is a suitable forecasting model for Indonesia, Philippines, and Malaysia and logistic growth curve suits the other countries in South Asia.
Mathematical modeling is a method of cognition of the surrounding world in which the description of the object is carried out in the language of mathematics, and the study of the model is performed ...using certain mathematical methods. Mathematical models based on ordinary differential equations (ODE) are used in the study of networks of different kinds, including the study of genetic regulatory networks (GRN). The use of ODE makes it possible to predict the evolution of GRN in time. Nonlinearity in these models is included in the form of a sigmoidal function. There are many of them, and in the literature, there are models that use different sigmoidal functions. The article discusses the models that use the logistic function and Gompertz function. The comparison of the results, related to three-dimensional networks, has been made. The text is accompanied by examples and illustrations.
The growth curves of fractal dimension of urban form take on squashing effect and can be described by sigmoid functions. The fractal dimension growth of urban form in western countries can be modeled ...by Boltzmann’s equation and logistic function. However, these models cannot be well applied to the fractal dimension growth curve of Beijing city, the national capital of China. In this paper, the experimental method is employed to find parametric models for the growth curves of fractal dimension of Chinese urban form. By statistical analysis, numerical analysis, and comparative analysis, we find that the quadratic Boltzmann equation and quadratic logistic function can be used to characterize how the fractal dimension of the urban land-use pattern of Beijing increases in the course of time. The models are also suitable for many cities in the north of China. In order to convert the empirical models into theoretical models, we attempt to construct a model of spatial replacement dynamics of urban evolution, from which the logistic model of urban fractal dimension growth can be derived. The models can be utilized to predict the rate and upper limitation of Chinese urban growth. In particular, the models can be employed to reveal the similarities and differences between the fractal growth of Chinese cities and that of the cities in western countries.
•The squashing effect of limit values of fractal dimension leads to sigmoid curves.•Urban fractal dimension growth curves can be modeled by quadratic Boltzmann equation.•Quadratic Boltzmann equation can be reduced to a quadratic logistic function.•Fractal dimension growth curves of urban form fall into two types.•Fractal dimension growth curves indicate two types of spatial dynamics of cities.
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The energy consumption problem is an important issue in the development process of various countries, and scientific methods for predicting energy consumption can assist governments in making ...decisions. The energy consumption trend usually shows a saturated S-shaped curve, and the mathematical model of the Logistic function can be used to fit this trend. Based on the Energy Logistic equation, a novel multivariable grey prediction model of energy consumption is proposed in this paper. The least square method is used to estimate the parameters of the model, and the approximate time response formula of the model is obtained. The degree of correlation between several energy consumptions is calculated by the grey correlation analysis. Then, from the angle of the three main energy sources to establish the energy consumption prediction model respectively, and the validity of the model is verified by selecting the data of three typical coal, crude oil and natural gas consumption provinces in China (Shandong Province, Heilongjiang Province and Guangdong Province). Compared with the other six multivariate grey models, the results show that the new model is superior to the other models according to five test indexes. Finally, based on the modelling of three provinces in China, the model predicts the consumption of three kinds of energy in the next five years, and a correlation analysis is performed according to the prediction results.
•A novel energy consumption grey prediction model ECGM(1,N) is proposed.•The influencing factors of the model are determined by grey correlation analysis.•The comparative study shows that the new model is superior to the other six models.•The novel model predicts three major energy of typical provinces in China.
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