scholarly journals Computation of subsurface drain spacing in the unsteady conditions using Artificial Neural Networks (ANN)

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Kaveh Ostad-Ali-Askari ◽  
Mohammad Shayannejad

AbstractArtificial neural networks are a tool for modeling of nonlinear systems in various engineering fields. These networks are effective tools for modeling the nonlinear systems. Each artificial neural network includes an input layer, an output layer between which there are one or some hidden layers. In each layer, there are one or several processing elements or neurons. The neurons of the input layer are independent variables of the understudy issue, and the neurons of the output layer are its dependent variables. Artificial neural system, through exerting weight on inputs and by suing an activation function attempts to achieve a desirable output. In this research, in order to calculate the drain spacing in an unsteady state in a region situated in the north east of Ahwaz, Iran with different soil properties and drain spacing, the artificial neural networks have been used. The neurons in the input layer were: Specific yield, hydraulic conductivity, depth of the impermeable layer, height of the water table in the middle of the interval between the drains in two-time steps. The neurons in output layer were drain spacing. The network designed in this research was included a hidden layer with four neurons. The distance of drains computed via this method had a good agreement with real values and had a high precision in compare with other methods.

Author(s):  
А.К. Бойцов ◽  
А.А. Логачев ◽  
Х.Г. Мусин

Оценка перспективности использования клонов гибридных пород древесины является одной из актуальных задач для повышения эффективности плантационного лесовыращивания. Одним из перспективных путей решения данной задачи является применение искусственных нейронных сетей (ИНС). Настоящая научная работа является одной из немногих, где применяется ИНС для решения подобных задач в лесном хозяйстве. Для обучения нейронных сетей и определения перспективности использования клонов гибридных пород древесины для плантационного лесовыращивания были взяты биометрические данные клонов гибридной осины 2018 г. В ходе выполнения работы были построены две ИНС, где архитектура первой сети включает входной слой из 3 нейронов, 1 скрытый слой с 6 нейронами и выходной слой из 1 нейрона; архитектура второй сети включает в себя входной слой из 3 нейронов, 2 скрытых слоя по 6 нейронов и выходной слой из 1 нейрона, в которые были загружены нормализованные исходные биометрические данные для обучения определения перспективности использования клонов гибридных пород древесины для плантационного лесовыращивания. По результатам данного исследования была составлена сравнительная характеристика точности ИНС 1 и ИНС 2, которая показала, что ИНС 1 более точная, так как её отклонение на 3,49% меньше ИНС 2. Результаты настоящей работы подтвердили перспективность применения ИНС для оценки использования клонов гибридных пород древесины для плантационного лесовыращивания. По оценке расчётной перспективности ИНС 1 для плантационного лесовыращивания были выявлены клоны гибридных пород древесины VTI, ESCH3, ESCH5. Внедрение ИНС в отрасль лесного хозяйства упрощает оценку результатов биометрических показателей древесины, особенно для начинающих специалистов, что обеспечивает последующую точную оценку перспективности пород древесины. Assessing the prospects of using hybrid wood clones is one of the urgent tasks to improve the efficiency of plantation silviculture. One of the promising ways to solve this problem is the use of artificial neural networks (ANN). This research work is one of the few where ANN are used to solve such problems in forestry. Biometric data from 2018 hybrid aspen clones were taken to train neural networks and determine the potential use of hybrid wood clones for plantation silviculture. During this work, two ANNs were constructed where the architecture of the first network includes an input layer of 3 neurons, 1 hidden layer with 6 neurons and an output layer of 1 neuron, the architecture of the second network includes an input layer of 3 neurons, 2 hidden layers of 6 neurons and an output layer of 1 neuron, into which the normalized input biometric data were loaded for learning to determine the prospective use of hybrid wood species clones for plantation silviculture. Based on the results of this study, a comparison of the accuracy of ANN 1 and ANN 2 was made, which showed that ANN 1 was more accurate because its bias was 3,49% less than ANN 2. The results of this work confirmed the promise of using ANN to evaluate the use of hybrid wood clones for plantation reforestation. According to the evaluation of the calculated promisingness of ANN 1 for plantation silviculture, VTI, ESCH3 and ESCH5 hybrid wood clones were identified. The introduction of ANN in the forestry industry simplifies the evaluation of wood biometric results, especially for beginners, which provides a subsequent accurate assessment of the perspective of wood species.


Author(s):  
Nadia Nedjah ◽  
Rodrigo Martins da Silva ◽  
Luiza de Macedo Mourelle

Artificial Neural Networks (ANNs) is a well known bio-inspired model that simulates human brain capabilities such as learning and generalization. ANNs consist of a number of interconnected processing units, wherein each unit performs a weighted sum followed by the evaluation of a given activation function. The involved computation has a tremendous impact on the implementation efficiency. Existing hardware implementations of ANNs attempt to speed up the computational process. However, these implementations require a huge silicon area that makes it almost impossible to fit within the resources available on a state-of-the-art FPGAs. In this chapter, a hardware architecture for ANNs that takes advantage of the dedicated adder blocks, commonly called MACs, to compute both the weighted sum and the activation function is devised. The proposed architecture requires a reduced silicon area considering the fact that the MACs come for free as these are FPGA’s built-in cores. Our system uses integer (fixed point) mathematics and operates with fractions to represent real numbers. Hence, floating point representation is not employed and any mathematical computation of the ANN hardware is based on combinational circuitry (performing only sums and multiplications). The hardware is fast because it is massively parallel. Besides, the proposed architecture can adjust itself on-the-fly to the user-defined configuration of the neural network, i.e., the number of layers and neurons per layer of the ANN can be settled with no extra hardware changes. This is a very nice characteristic in robot-like systems considering the possibility of the same hardware may be exploited in different tasks. The hardware also requires another system (a software) that controls the sequence of the hardware computation and provides inputs, weights and biases for the ANN in hardware. Thus, a co-design environment is necessary.


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 567
Author(s):  
Jolanta Wawrzyniak

Artificial neural networks (ANNs) constitute a promising modeling approach that may be used in control systems for postharvest preservation and storage processes. The study investigated the ability of multilayer perceptron and radial-basis function ANNs to predict fungal population levels in bulk stored rapeseeds with various temperatures (T = 12–30 °C) and water activity in seeds (aw = 0.75–0.90). The neural network model input included aw, temperature, and time, whilst the fungal population level was the model output. During the model construction, networks with a different number of hidden layer neurons and different configurations of activation functions in neurons of the hidden and output layers were examined. The best architecture was the multilayer perceptron ANN, in which the hyperbolic tangent function acted as an activation function in the hidden layer neurons, while the linear function was the activation function in the output layer neuron. The developed structure exhibits high prediction accuracy and high generalization capability. The model provided in the research may be readily incorporated into control systems for postharvest rapeseed preservation and storage as a support tool, which based on easily measurable on-line parameters can estimate the risk of fungal development and thus mycotoxin accumulation.


2013 ◽  
Vol 339 ◽  
pp. 55-58
Author(s):  
Xue Ye Chen ◽  
Hui Xu

The micromixer device is modeled using artificial neural networks trained with finite element simulations of the underlying incompressible Navier-Stokes and mass transport PDEs. The neural networks design is based on a three layers perceptron with one input layer, one nonlinear hidden layer and one linear output layer. The neural networks can map the micromixer behavior into a set of analytical performance functions parameterized by the systems physical variables. The macromodel has been extracted from training output of the artificial neural networks. Three design variables, i.e., the flow velocity, the channel width, and the numbers of the mixing unit are selected for model design. The mixing index at the end of the serpentine channels is employed as the objective function. The macromodel has been validated with numerical simulations. It can be demonstrated that this macromodel should facilitate the design of microfluidic device with sophisticated channels networks.


Author(s):  
H. Bazargan ◽  
H. Bahai ◽  
F. Aryana ◽  
S. F. Yasseri

The aim of this work is to simulate the 3-houly mean zero-up-crossing wave periods (Tzs) of the sea-states of a future period for a location in the North East Pacific. Seven multi-layer artificial neural networks (ANNs) were trained with simulated annealing algorithm. The output of each ANN was used for estimating each of the 7 parameters of a new distribution, described in Appendix A, called hepta-parameter spline proposed for the conditional distribution of the Tz given some significant wave heights and mean zero-up-crossing wave periods. After estimating the parameters of the conditional distributions, the Tzs have been forecasted from the hepta-parameter spline distributions corresponding to the Tzs of the period.


1997 ◽  
Vol 9 (5) ◽  
pp. 1109-1126
Author(s):  
Zhiyu Tian ◽  
Ting-Ting Y. Lin ◽  
Shiyuan Yang ◽  
Shibai Tong

With the progress in hardware implementation of artificial neural networks, the ability to analyze their faulty behavior has become increasingly important to their diagnosis, repair, reconfiguration, and reliable application. The behavior of feedforward neural networks with hard limiting activation function under stuck-at faults is studied in this article. It is shown that the stuck-at-M faults have a larger effect on the network's performance than the mixed stuck-at faults, which in turn have a larger effect than that of stuck-at-0 faults. Furthermore, the fault-tolerant ability of the network decreases with the increase of its size for the same percentage of faulty interconnections. The results of our analysis are validated by Monte-Carlo simulations.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Reginald B. Silva ◽  
Piero Iori ◽  
Cecilia Armesto ◽  
Hugo N. Bendini

Soil loss is one of the main causes of pauperization and alteration of agricultural soil properties. Various empirical models (e.g., USLE) are used to predict soil losses from climate variables which in general have to be derived from spatial interpolation of point measurements. Alternatively, Artificial Neural Networks may be used as a powerful option to obtain site-specific climate data from independent factors. This study aimed to develop an artificial neural network to estimate rainfall erosivity in the Ribeira Valley and Coastal region of the State of São Paulo. In the development of the Artificial Neural Networks the input variables were latitude, longitude, and annual rainfall and a mathematical equation of the activation function for use in the study area as the output variable. It was found among other things that the Artificial Neural Networks can be used in the interpolation of rainfall erosivity values for the Ribeira Valley and Coastal region of the State of São Paulo to a satisfactory degree of precision in the estimation of erosion. The equation performance has been demonstrated by comparison with the mathematical equation of the activation function adjusted to the specific conditions of the study area.


2003 ◽  
Vol 14 (6) ◽  
pp. 1576-1579 ◽  
Author(s):  
E. Soria-Olivas ◽  
J.D. Martin-Guerrero ◽  
G. Camps-Valls ◽  
A.J. Serrano-Lopez ◽  
J. Calpe-Maravilla ◽  
...  

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