-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathModel_Simulation_Notes.txt
82 lines (71 loc) · 4.33 KB
/
Model_Simulation_Notes.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
CENTRAL IDEA: Neural Networks can be used to approximate highly nonlinear functions very efficiently
-Most important aspects of successful training and use:
-Very good understanding of data
-What is it that you're solving for?
-What kinds of input features do you have access to? (Not too many, as this may result in noise)
-Most useful when relationships between parameters in equation are unknown, but large amounts of data exist
Probability Density Estimation Using Artificial Neural Networks (2000): B
-Probability Density Functions (pdf): important computational problem with applications all over physics
-Training data comes from non-parametric technique for pdf estimation (least amount of parameters as possible)
-Train data across many parameter values
Modelling and Prediction of Hourly NOx and NO2 concentrations in London (1998): A-
-Nitrogen Oxides (NO) are emitted into urban atmosphere primarily from vehicle exhausts
-Much effort in attempting to forecast pollutants
-Training data:
-Input data: measurements of meteorological conditions
-Output: pollutant concentration
-Architecture: two hidden layers with 20 nodes each
-Activation function: hyperbolic tangent (output layer used identity function??)
-6 meteorlogical variables used for input
-All data normalized between -1 and 1 (just like activation output)
-This model worked considerably better than previous models
Neural Network Modelling of Coastal Algal Blooms (2003): A+
-Major algal blooms around Hong-Kong and South China cause many problems for environment
-Early warning to such phenomena would allow fish farmers to help wildlife
-NNs represent opportunity because of ability to predict complicated patterns
-Activation function: sigmoid (thus output data must be normalized between 0 and 1; could this be avoided with ReLu?)
-Training data:
-Monthly/biweekly water quality data
-Data from 1982-1992 used to train; data from 1993-2000 used to test
-Based on simplest number of input variables known to affect algal dynamics (nine variables)
-Architecture: one hidden layer with 3 neurons
Neural Network Modelling of Wave Overtopping at Coastal Structures (2007): B-
-For safety assessment of coastal structures, reliable predictions of wave overtopping are required
-Each data point described by number of parameters that represent hydraulic/structural information
-Data preprocessed to remove bad outliers
-Training data:
-Total database consisted of 8372 tests
-15 total parameters used
-All inputs and outputs scaled
-Cost function: Root-mean-squared
-Architecture: 1 hidden layer with 20 neurons
Neural Network Model for Bankruptcy Prediction (1990): A
-Generalization: method for using neural networks for predictions
-Sample: firms that went bankrupt between 1975 and 1982 (129 firms, 65 bankrupt, 64 non-bankrupt)
-Training data:
-74 firms data (last financial statements issued before firms declared bankruptcy)
-Input: 5 fincancial ratios
-Architecture: 1 hidden layer with 5 nodes
-Output: scale between 0 and 1; firms below .5 classified as bankrupt, firms above .5 non-bankrupt
-Converged after 191,400 iterations
Neural Network for Predicting Features of Osmotically Dehydrated Pumpkin (2017): A-
-Pumpkin is very sensitive to spoilage, so it must be dried or frozen
-Color of food product is most important quality parameter considered by consumers
-Input: three variables (sucrose concentration, solution temperature, immersion time)
-Output: three variables, three networks (color changes, shrinkage, texture)
-Architecture: 1 hidden layer with 4 neurons
-Activation function: tangent sigmoid transfer function
-27 sets of data used (three of each input variable)
-Input and output normalized between 0 and 1
Applications of Artificial Neural Networks (2017): C+
-Data mining: extracting knowledge from large amounts of data
-Accuracy increases with number of training cases
-NNs represent one type of data mining
Convolutional Neural Network with AdaBoost (2017) : A
-Basic idea: use AdaBoost with strong classifiers (CNN)
-Works very well by allowing CNNs to vote on output values
Multi-Level Attention Network (2017): A
-Combination of CNN and RNN to classify a picture
-Concept of AI Attention one of most exciting in current research
-Gets us closer to fully functional AI
-Allows AI to identify images (used to be impossible)