616 research outputs found
Generative Adversarial Networks via a Composite Annealing of Noise and Diffusion
Generative adversarial network (GAN) is a framework for generating fake data
using a set of real examples. However, GAN is unstable in the training stage.
In order to stabilize GANs, the noise injection has been used to enlarge the
overlap of the real and fake distributions at the cost of increasing variance.
The diffusion (or smoothing) may reduce the intrinsic underlying dimensionality
of data but it suppresses the capability of GANs to learn high-frequency
information in the training procedure. Based on these observations, we propose
a data representation for the GAN training, called noisy scale-space (NSS),
that recursively applies the smoothing with a balanced noise to data in order
to replace the high-frequency information by random data, leading to a
coarse-to-fine training of GANs. We experiment with NSS using DCGAN and
StyleGAN2 based on benchmark datasets in which the NSS-based GANs outperforms
the state-of-the-arts in most cases
Regularization in neural network optimization via trimmed stochastic gradient descent with noisy label
Regularization is essential for avoiding over-fitting to training data in
neural network optimization, leading to better generalization of the trained
networks. The label noise provides a strong implicit regularization by
replacing the target ground truth labels of training examples by uniform random
labels. However, it may also cause undesirable misleading gradients due to the
large loss associated with incorrect labels. We propose a first-order
optimization method (Label-Noised Trim-SGD) which combines the label noise with
the example trimming in order to remove the outliers. The proposed algorithm
enables us to impose a large label noise and obtain a better regularization
effect than the original methods. The quantitative analysis is performed by
comparing the behavior of the label noise, the example trimming, and the
proposed algorithm. We also present empirical results that demonstrate the
effectiveness of our algorithm using the major benchmarks and the fundamental
networks, where our method has successfully outperformed the state-of-the-art
optimization methods
Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications
This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results
- …