scholarly journals A Domain-Independent Generative Adversarial Network for Activity Recognition Using WiFi CSI Data

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7852
Author(s):  
Augustinas Zinys ◽  
Bram van Berlo ◽  
Nirvana Meratnia
Keyword(s):  
Data Collection ◽  
Activity Recognition ◽  
Vital Signs ◽  
Learning Task ◽  
Model Complexity ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Processing Module ◽  
Device Free ◽  
Domain Independent

Over the past years, device-free sensing has received considerable attention due to its unobtrusiveness. In this regard, context recognition using WiFi Channel State Information (CSI) data has gained popularity, and various techniques have been proposed that combine unobtrusive sensing and deep learning to accurately detect various contexts ranging from human activities to gestures. However, research has shown that the performance of these techniques significantly degrades due to change in various factors including sensing environment, data collection configuration, diversity of target subjects, and target learning task (e.g., activities, gestures, emotions, vital signs). This problem, generally known as the domain change problem, is typically addressed by collecting more data and learning the data distribution that covers multiple factors impacting the performance. However, activity recognition data collection is a very labor-intensive and time consuming task, and there are too many known and unknown factors impacting WiFi CSI signals. In this paper, we propose a domain-independent generative adversarial network for WiFi CSI based activity recognition in combination with a simplified data pre-processing module. Our evaluation results show superiority of our proposed approach compared to the state of the art in terms of increased robustness against domain change, higher accuracy of activity recognition, and reduced model complexity.

scholarly journals Enhance Image as You Like with Unpaired Learning

2021 ◽  
Author(s):  
Xiaopeng Sun ◽  
Muxingzi Li ◽  
Tianyu He ◽  
Lubin Fan
Keyword(s):  
Learning Task ◽  
User Preferences ◽  
Generative Adversarial Networks ◽  
Low Light ◽  
Generative Adversarial Network ◽  
Light Image ◽  
Adversarial Network ◽  
Reference Images ◽  
Ill Posed ◽  
Normal Light

Low-light image enhancement exhibits an ill-posed nature, as a given image may have many enhanced versions, yet recent studies focus on building a deterministic mapping from input to an enhanced version. In contrast, we propose a lightweight one-path conditional generative adversarial network (cGAN) to learn a one-to-many relation from low-light to normal-light image space, given only sets of low- and normal-light training images without any correspondence. By formulating this ill-posed problem as a modulation code learning task, our network learns to generate a collection of enhanced images from a given input conditioned on various reference images. Therefore our inference model easily adapts to various user preferences, provided with a few favorable photos from each user. Our model achieves competitive visual and quantitative results on par with fully supervised methods on both noisy and clean datasets, while being 6 to 10 times lighter than state-of-the-art generative adversarial networks (GANs) approaches.

Semi Supervised Generative Adversarial Network for Automated Glaucoma Diagnosis with Stacked Discriminator Models

2021 ◽  
Vol 11 (5) ◽  
pp. 1334-1340
Author(s):  
K. Gokul Kannan ◽  
T. R. Ganesh Babu
Keyword(s):  
Network Architecture ◽  
Super Resolution ◽  
Unsupervised Classification ◽  
Learning Task ◽  
Generative Models ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Glaucoma Diagnosis ◽  
Image Translation

Generative Adversarial Network (GAN) is neural network architecture, widely used in many computer vision applications such as super-resolution image generation, art creation and image to image translation. A conventional GAN model consists of two sub-models; generative model and discriminative model. The former one generates new samples based on an unsupervised learning task, and the later one classifies them into real or fake. Though GAN is most commonly used for training generative models, it can be used for developing a classifier model. The main objective is to extend the effectiveness of GAN into semi-supervised learning, i.e., for the classification of fundus images to diagnose glaucoma. The discriminator model in the conventional GAN is improved via transfer learning to predict n + 1 classes by training the model for both supervised classification (n classes) and unsupervised classification (fake or real). Both models share all feature extraction layers and differ in the output layers. Thus any update in one of the model will impact both models. Results show that the semi-supervised GAN performs well than a standalone Convolution Neural Networks (CNNs) model.

scholarly journals Extreme Low-Resolution Activity Recognition Using a Super-Resolution-Oriented Generative Adversarial Network

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 670
Author(s):  
Mingzheng Hou ◽  
Song Liu ◽  
Jiliu Zhou ◽  
Yi Zhang ◽  
Ziliang Feng
Keyword(s):  
Activity Recognition ◽  
Large Scale ◽  
Super Resolution ◽  
General Activity ◽  
Low Resolution ◽  
Generative Adversarial Network ◽  
Video Clips ◽  
Adversarial Network ◽  
Efficient Recognition ◽  
Low Resolution Images

Activity recognition is a fundamental and crucial task in computer vision. Impressive results have been achieved for activity recognition in high-resolution videos, but for extreme low-resolution videos, which capture the action information at a distance and are vital for preserving privacy, the performance of activity recognition algorithms is far from satisfactory. The reason is that extreme low-resolution (e.g., 12 × 16 pixels) images lack adequate scene and appearance information, which is needed for efficient recognition. To address this problem, we propose a super-resolution-driven generative adversarial network for activity recognition. To fully take advantage of the latent information in low-resolution images, a powerful network module is employed to super-resolve the extremely low-resolution images with a large scale factor. Then, a general activity recognition network is applied to analyze the super-resolved video clips. Extensive experiments on two public benchmarks were conducted to evaluate the effectiveness of our proposed method. The results demonstrate that our method outperforms several state-of-the-art low-resolution activity recognition approaches.

scholarly journals Deep Convolutional Generative Adversarial Network and Convolutional Neural Network for Smoke Detection

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hang Yin ◽  
Yurong Wei ◽  
Hedan Liu ◽  
Shuangyin Liu ◽  
Chuanyun Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Data Collection ◽  
Convolutional Neural Network ◽  
Early Warning ◽  
Dynamic Scene ◽  
Smoke Detection ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Vibe Algorithm ◽  
Good Detection

Real-time smoke detection is of great significance for early warning of fire, which can avoid the serious loss caused by fire. Detecting smoke in actual scenes is still a challenging task due to large variance of smoke color, texture, and shapes. Moreover, the smoke detection in the actual scene is faced with the difficulties in data collection and insufficient smoke datasets, and the smoke morphology is susceptible to environmental influences. To improve the performance of smoke detection and solve the problem of too few datasets in real scenes, this paper proposes a model that combines a deep convolutional generative adversarial network and a convolutional neural network (DCG-CNN) to extract smoke features and detection. The vibe algorithm was used to collect smoke and nonsmoke images in the dynamic scene and deep convolutional generative adversarial network (DCGAN) used these images to generate images that are as realistic as possible. Besides, we designed an improved convolutional neural network (CNN) model for extracting smoke features and smoke detection. The experimental results show that the method has a good detection performance on the smoke generated in the actual scenes and effectively reduces the false alarm rate.

scholarly journals Improving Road Surface Area Extraction via Semantic Segmentation with Conditional Generative Learning for Deep Inpainting Operations

2022 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Calimanut-Ionut Cira ◽  
Martin Kada ◽  
Miguel-Ángel Manso-Callejo ◽  
Ramón Alcarria ◽  
Borja Bordel Bordel Sanchez
Keyword(s):  
Surface Area ◽  
Large Scale ◽  
Semantic Segmentation ◽  
Learning Task ◽  
Road Surface ◽  
Generative Learning ◽  
Post Processing ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Unseen Data

The road surface area extraction task is generally carried out via semantic segmentation over remotely-sensed imagery. However, this supervised learning task is often costly as it requires remote sensing images labelled at the pixel level, and the results are not always satisfactory (presence of discontinuities, overlooked connection points, or isolated road segments). On the other hand, unsupervised learning does not require labelled data and can be employed for post-processing the geometries of geospatial objects extracted via semantic segmentation. In this work, we implement a conditional Generative Adversarial Network to reconstruct road geometries via deep inpainting procedures on a new dataset containing unlabelled road samples from challenging areas present in official cartographic support from Spain. The goal is to improve the initial road representations obtained with semantic segmentation models via generative learning. The performance of the model was evaluated on unseen data by conducting a metrical comparison where a maximum Intersection over Union (IoU) score improvement of 1.3% was observed when compared to the initial semantic segmentation result. Next, we evaluated the appropriateness of applying unsupervised generative learning using a qualitative perceptual validation to identify the strengths and weaknesses of the proposed method in very complex scenarios and gain a better intuition of the model’s behaviour when performing large-scale post-processing with generative learning and deep inpainting procedures and observed important improvements in the generated data.

ORGANIC (1).pdf

2017 ◽  
Author(s):  
Benjamin Sanchez-Lengeling ◽  
Carlos Outeiral ◽  
Gabriel L. Guimaraes ◽  
Alan Aspuru-Guzik
Keyword(s):  
Machine Learning ◽  
Learning Community ◽  
Chemical Species ◽  
Material Design ◽  
Organic Photovoltaic ◽  
Generative Adversarial Networks ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Adversarial Networks ◽  
Photovoltaic Material

Molecular discovery seeks to generate chemical species tailored to very specific needs. In this paper, we present ORGANIC, a framework based on Objective-Reinforced Generative Adversarial Networks (ORGAN), capable of producing a distribution over molecular space that matches with a certain set of desirable metrics. This methodology combines two successful techniques from the machine learning community: a Generative Adversarial Network (GAN), to create non-repetitive sensible molecular species, and Reinforcement Learning (RL), to bias this generative distribution towards certain attributes. We explore several applications, from optimization of random physicochemical properties to candidates for drug discovery and organic photovoltaic material design.

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