NEURAL NETWORKS ARE A NEW MILESTONE IN THE DEVELOPTMENT OF SCIENCE AND DESIGNE. BRIEF OVERVIEW OR THE PROBLEM

Author(s):  
Игорь Иванович Орлов ◽  
Екатерина Леонидовна Ларских

В статье рассматривается краткая история развития нового направления в науке и дизайн - программировании под названием «нейронная сеть». Авторами выделены, описаны и проанализированы этапы генезиса развития от вакуумных ламп и перцептронов до компьютерных программ нашего времени, которые позволяют раскрыть более полную картину возможностей нейросетей. The article considers a brief history of the development of a new direction in science and design programming called the «neural network». These networks are capable not only of receiving and processing the information received, but also of further training and self-development. The authors highlighted, described and analyzed the stages of development genesis from vacuum lamps and perceptrons to computer programs of our time, which allow to reveal a more complete picture of the possibilities opened by neural networks.

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3796-3796
Author(s):  
Romy Kremers ◽  
Stéphane Zuily ◽  
Philip De Groot ◽  
Coenraad Hemker ◽  
Denis Wahl ◽  
...  

Abstract Background: The antiphospholipid syndrome (APS) is characterized by the presence of antiphospholipid antibodies directed against β2-glycoprotein I (β2GPI) and/or cardiolipin. APS is associated with an increased risk of thrombosis and APS patients are known to have an altered thrombin generation (TG) profile. However, a single TG parameter cannot to differentiate between patients with or without a history of thrombosis. Therefore, we used a novel machine learning approach called 'neural networking' to search for hidden patterns in the clinical and experimental data of APS patients that identify patients with a high risk of thrombosis. In this method a neural network (NN) is trained using an existing dataset of APS patients. Training of the neural network ensures that it learns to classify samples (in this case patient with or without prior thrombosis) using the selected clinical and experimental database. Once the network has been trained and tested it can be used to differentiate between (new) APS patients with and without a history of thrombosis. Aim: To develop a neural network to predict thrombosis in APS patients based on their antibody profile and TG results. Materials and methods: Thirty-one non-anticoagulated APS patients (obstetric and thrombotic) were enrolled in the study after approval of the local ethics committee and after informed consent was obtained. Thrombosis had occurred in 21 APS patients either as arterial, venous or small vessel thrombosis. Thrombin generation was measured at 1 pM tissue factor (TF) and thrombin dynamics analysis was performed to study prothrombin conversion and thrombin inactivation. The sensitivity of the activated protein C system was tested by measuring TG in the presence and absence of 20 nM thrombomodulin (TM). The presence of aPL was defined as positivity for Lupus Anticoagulant and/or anticardiolipin (aCL) and/or β2GPI determined by enzyme linked immunosorbent assays (ELISA). LA was assessed according to the three-steps guidelines of the Subcommitee on LA of the International Society on Thrombosis and Haemostasis (ISTH) using Partial Thromboplastin Time - Lupus Anticoagulant (PTT-LA) and dilute Russel's Viper VenomTime (dRVVT) reagents. Multiple neural networks were trained and tested to predict whether a patient had a history of thrombosis using the Machine Learning Toolbox of Matlab. The input of the neural network consisted of the antibody profile and/or TG data (Figure 2). Results: The percentage of patients with antibodies against β2-glycoprotein I and cardiolipin did not differ between patients with and without prior thrombosis (Figure 1). Thrombin generation ETP (but not peak height) was significantly elevated in the thrombosis group. Due to overlap between the groups, it was not possible to distinguish between patients with and without a history of thrombosis (Figure 1). Two neural networks were trained (Figure 2): one based solely on the antibody profile of the patients and the other based on both the antibody profile and the TG results. The prediction accuracy of both neural networks was assessed in the testing phase of the NN development. The NN solely based on the antibody profile identified patients with a history of thrombosis with an accuracy of 82.2%. However, it was not capable of ruling out thrombosis in the non-thrombosis group (48.6% correctly classified vs. 51.4% incorrectly classified). The addition of the thrombin generation profile to the NN increased the prediction accuracy in the thrombosis group to 86.6%, but more interestingly, it also improved the capability of the NN to rule out thrombosis in the non-thrombosis group to 63.0%. Discussion: The development of thrombosis in APS is a complex process influenced by many factors, represented by alterations of various diagnostic variables, such as the antibody profile and the thrombin generation outcome. The presence of a certain antibody or the elevation of a single TG parameter was unable to predict thrombosis in APS. The integration of all data via neural networking circumvents this problem and can predict which patient had a prior thrombosis with an accuracy of 86.6% based on a combination of the antibody profile and thrombin generation parameters. The next step will be to test this approach in a prospective cohort of APS patients to develop a neural network to predict future thrombotic events in APS patients. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 2020 (10) ◽  
pp. 54-62
Author(s):  
Oleksii VASYLIEV ◽  

The problem of applying neural networks to calculate ratings used in banking in the decision-making process on granting or not granting loans to borrowers is considered. The task is to determine the rating function of the borrower based on a set of statistical data on the effectiveness of loans provided by the bank. When constructing a regression model to calculate the rating function, it is necessary to know its general form. If so, the task is to calculate the parameters that are included in the expression for the rating function. In contrast to this approach, in the case of using neural networks, there is no need to specify the general form for the rating function. Instead, certain neural network architecture is chosen and parameters are calculated for it on the basis of statistical data. Importantly, the same neural network architecture can be used to process different sets of statistical data. The disadvantages of using neural networks include the need to calculate a large number of parameters. There is also no universal algorithm that would determine the optimal neural network architecture. As an example of the use of neural networks to determine the borrower's rating, a model system is considered, in which the borrower's rating is determined by a known non-analytical rating function. A neural network with two inner layers, which contain, respectively, three and two neurons and have a sigmoid activation function, is used for modeling. It is shown that the use of the neural network allows restoring the borrower's rating function with quite acceptable accuracy.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Idris Kharroubi ◽  
Thomas Lim ◽  
Xavier Warin

AbstractWe study the approximation of backward stochastic differential equations (BSDEs for short) with a constraint on the gains process. We first discretize the constraint by applying a so-called facelift operator at times of a grid. We show that this discretely constrained BSDE converges to the continuously constrained one as the mesh grid converges to zero. We then focus on the approximation of the discretely constrained BSDE. For that we adopt a machine learning approach. We show that the facelift can be approximated by an optimization problem over a class of neural networks under constraints on the neural network and its derivative. We then derive an algorithm converging to the discretely constrained BSDE as the number of neurons goes to infinity. We end by numerical experiments.


Author(s):  
Saša Vasiljević ◽  
Jasna Glišović ◽  
Nadica Stojanović ◽  
Ivan Grujić

According to the World Health Organization, air pollution with PM10 and PM2.5 (PM-particulate matter) is a significant problem that can have serious consequences for human health. Vehicles, as one of the main sources of PM10 and PM2.5 emissions, pollute the air and the environment both by creating particles by burning fuel in the engine, and by wearing of various elements in some vehicle systems. In this paper, the authors conducted the prediction of the formation of PM10 and PM2.5 particles generated by the wear of the braking system using a neural network (Artificial Neural Networks (ANN)). In this case, the neural network model was created based on the generated particles that were measured experimentally, while the validity of the created neural network was checked by means of a comparative analysis of the experimentally measured amount of particles and the prediction results. The experimental results were obtained by testing on an inertial braking dynamometer, where braking was performed in several modes, that is under different braking parameters (simulated vehicle speed, brake system pressure, temperature, braking time, braking torque). During braking, the concentration of PM10 and PM2.5 particles was measured simultaneously. The total of 196 measurements were performed and these data were used for training, validation, and verification of the neural network. When it comes to simulation, a comparison of two types of neural networks was performed with one output and with two outputs. For each type, network training was conducted using three different algorithms of backpropagation methods. For each neural network, a comparison of the obtained experimental and simulation results was performed. More accurate prediction results were obtained by the single-output neural network for both particulate sizes, while the smallest error was found in the case of a trained neural network using the Levenberg-Marquardt backward propagation algorithm. The aim of creating such a prediction model is to prove that by using neural networks it is possible to predict the emission of particles generated by brake wear, which can be further used for modern traffic systems such as traffic control. In addition, this wear algorithm could be applied on other vehicle systems, such as a clutch or tires.


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1526 ◽  
Author(s):  
Choongmin Kim ◽  
Jacob A. Abraham ◽  
Woochul Kang ◽  
Jaeyong Chung

Crossbar-based neuromorphic computing to accelerate neural networks is a popular alternative to conventional von Neumann computing systems. It is also referred as processing-in-memory and in-situ analog computing. The crossbars have a fixed number of synapses per neuron and it is necessary to decompose neurons to map networks onto the crossbars. This paper proposes the k-spare decomposition algorithm that can trade off the predictive performance against the neuron usage during the mapping. The proposed algorithm performs a two-level hierarchical decomposition. In the first global decomposition, it decomposes the neural network such that each crossbar has k spare neurons. These neurons are used to improve the accuracy of the partially mapped network in the subsequent local decomposition. Our experimental results using modern convolutional neural networks show that the proposed method can improve the accuracy substantially within about 10% extra neurons.


1991 ◽  
Vol 45 (10) ◽  
pp. 1706-1716 ◽  
Author(s):  
Mark Glick ◽  
Gary M. Hieftje

Artificial neural networks were constructed for the classification of metal alloys based on their elemental constituents. Glow discharge-atomic emission spectra obtained with a photodiode array spectrometer were used in multivariate calibrations for 7 elements in 37 Ni-based alloys (different types) and 15 Fe-based alloys. Subsets of the two major classes formed calibration sets for stepwise multiple linear regression. The remaining samples were used to validate the calibration models. Reference data from the calibration sets were then pooled into a single set to train neural networks with different architectures and different training parameters. After the neural networks learned to discriminate correctly among alloy classes in the training set, their ability to classify samples in the testing set was measured. In general, the neural network approach performed slightly better than the K-nearest neighbor method, but it suffered from a hidden classification mechanism and nonunique solutions. The neural network methodology is discussed and compared with conventional sample-classification techniques, and multivariate calibration of glow discharge spectra is compared with conventional univariate calibration.


2016 ◽  
Vol 38 (2) ◽  
pp. 37-46 ◽  
Author(s):  
Mateusz Kaczmarek ◽  
Agnieszka Szymańska

Abstract Nonlinear structural mechanics should be taken into account in the practical design of reinforced concrete structures. Cracking is one of the major sources of nonlinearity. Description of deflection of reinforced concrete elements is a computational problem, mainly because of the difficulties in modelling the nonlinear stress-strain relationship of concrete and steel. In design practise, in accordance with technical rules (e.g., Eurocode 2), a simplified approach for reinforced concrete is used, but the results of simplified calculations differ from the results of experimental studies. Artificial neural network is a versatile modelling tool capable of making predictions of values that are difficult to obtain in numerical analysis. This paper describes the creation and operation of a neural network for making predictions of deflections of reinforced concrete beams at different load levels. In order to obtain a database of results, that is necessary for training and testing the neural network, a research on measurement of deflections in reinforced concrete beams was conducted by the authors in the Certified Research Laboratory of the Building Engineering Institute at Wrocław University of Science and Technology. The use of artificial neural networks is an innovation and an alternative to traditional methods of solving the problem of calculating the deflections of reinforced concrete elements. The results show the effectiveness of using artificial neural network for predicting the deflection of reinforced concrete beams, compared with the results of calculations conducted in accordance with Eurocode 2. The neural network model presented in this paper can acquire new data and be used for further analysis, with availability of more research results.


2014 ◽  
Vol 38 (6) ◽  
pp. 1681-1693 ◽  
Author(s):  
Braz Calderano Filho ◽  
Helena Polivanov ◽  
César da Silva Chagas ◽  
Waldir de Carvalho Júnior ◽  
Emílio Velloso Barroso ◽  
...  

Soil information is needed for managing the agricultural environment. The aim of this study was to apply artificial neural networks (ANNs) for the prediction of soil classes using orbital remote sensing products, terrain attributes derived from a digital elevation model and local geology information as data sources. This approach to digital soil mapping was evaluated in an area with a high degree of lithologic diversity in the Serra do Mar. The neural network simulator used in this study was JavaNNS and the backpropagation learning algorithm. For soil class prediction, different combinations of the selected discriminant variables were tested: elevation, declivity, aspect, curvature, curvature plan, curvature profile, topographic index, solar radiation, LS topographic factor, local geology information, and clay mineral indices, iron oxides and the normalized difference vegetation index (NDVI) derived from an image of a Landsat-7 Enhanced Thematic Mapper Plus (ETM+) sensor. With the tested sets, best results were obtained when all discriminant variables were associated with geological information (overall accuracy 93.2 - 95.6 %, Kappa index 0.924 - 0.951, for set 13). Excluding the variable profile curvature (set 12), overall accuracy ranged from 93.9 to 95.4 % and the Kappa index from 0.932 to 0.948. The maps based on the neural network classifier were consistent and similar to conventional soil maps drawn for the study area, although with more spatial details. The results show the potential of ANNs for soil class prediction in mountainous areas with lithological diversity.


Author(s):  
Daniel Roten ◽  
Kim B. Olsen

ABSTRACT We use deep learning to predict surface-to-borehole Fourier amplification functions (AFs) from discretized shear-wave velocity profiles. Specifically, we train a fully connected neural network and a convolutional neural network using mean AFs observed at ∼600 KiK-net vertical array sites. Compared with predictions based on theoretical SH 1D amplifications, the neural network (NN) results in up to 50% reduction of the mean squared log error between predictions and observations at sites not used for training. In the future, NNs may lead to a purely data-driven prediction of site response that is independent of proxies or simplifying assumptions.


Author(s):  
Jason K. Ostanek

In much of the public literature on pin-fin heat transfer, Nusselt number is presented as a function of Reynolds number using a power-law correlation. Power-law correlations typically have an accuracy of 20% while the experimental uncertainty of such measurements is typically between 5% and 10%. Additionally, the use of power-law correlations may require many sets of empirical constants to fully characterize heat transfer for different geometrical arrangements. In the present work, artificial neural networks were used to predict heat transfer as a function of streamwise spacing, spanwise spacing, pin-fin height, Reynolds number, and row position. When predicting experimental heat transfer data, the neural network was able to predict 73% of array-averaged heat transfer data to within 10% accuracy while published power-law correlations predicted 48% of the data to within 10% accuracy. Similarly, the neural network predicted 81% of row-averaged data to within 10% accuracy while 52% of the data was predicted to within 10% accuracy using power-law correlations. The present work shows that first-order heat transfer predictions may be simplified by using a single neural network model rather than combining or interpolating between power-law correlations. Furthermore, the neural network may be expanded to include additional pin-fin features of interest such as fillets, duct rotation, pin shape, pin inclination angle, and more making neural networks expandable and adaptable models for predicting pin-fin heat transfer.


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