Search : [ author: 한지형 ] (4)

A Proposal for Lightweight Human Action Recognition Model with Video Frame Selection for Residential Area

Sohyeon Kim, Ji-Hyeong Han

http://doi.org/10.5626/JOK.2023.50.12.1111

Residential area closed-circuit televisions (CCTVs) need human action recognition (HAR) to predict any accidents and crucial problems. HAR model must be not only accurate but also light and fast to apply in the real world. Therefore, in this paper, a cross-modal PoseC3D model with a frame selection method is proposed. The proposed cross-modal PoseC3D model integrates multi-modality inputs (i.e., RGB image and human skeleton data) and trains them in a single model. Thus, the proposed model is lighter and faster than previous works such as two-pathway PoseC3D. Moreover, we apply the frame selection method to use only the meaningful frames based on differences between frames instead of using the whole frame of a video. AI Hub open dataset was used to verify the performance of proposed method. The experimental results showed that the proposed method achieves similar or better performance and is much lighter and faster than those in the previous works.

Copy-Paste Based Image Data Augmentation Method Using

Su-A Lee, Ji-Hyeong Han

http://doi.org/10.5626/JOK.2022.49.12.1056

In the field of computer vision, massive well-annotated image data are essential to achieve good performance of a convolutional neural network (CNN) model. However, in real world applications, gathering massive well-annotated data is a difficult and time-consuming job. Thus, image data augmentation has been continually studied. In this paper, we proposed an image data augmentation method that could generate more diverse image data by combining generative adversarial network (GAN) and copy-paste based augmentation. The proposed method generated not pixel-level or image-level augmentation, but object-level augmentation by cutting off segmentation boundaries(mask) instead of bounding boxes. It then applyied GAN to transform objects.

Layer-wise Relevance Propagation (LRP) Based Technical and Macroeconomic Indicator Impact Analysis for an Explainable Deep Learning Model to Predict an Increase and Decrease in KOSPI

Jae-Eung Lee, Ji-Hyeong Han

http://doi.org/10.5626/JOK.2021.48.12.1289

Most of the research on stock prediction using artificial intelligence has focused on improving the accuracy. However, reliability, transparency, and equity of decision-making should be secured in the field of finance. This study proposes a layer-wise relevance propagation (LRP) approach to create an explainable stock prediction deep learning model, which is trained using macroeconomic and technical indicators as the input features. Also, the definition of the problem is simplified by prediction of an increase or decrease in the KOSPI closing price from the previous day instead of prediction of the KOSPI value itself. To show how the proposed method works, experiments are conducted. The results show that the model trained with data by the selected features via LRP is more accurate than the vanilla model. Moreover, we show that LRP results are meaningful by analyzing the tendency of the positive effect of each feature for the prediction results.

ChannelAug: A New Approach to Data Augmentation for Improving Image Classification Performance in Uncertain Environments

Hyeok Yoon, Soohan Kang, Ji-Hyeong Han

http://doi.org/10.5626/JOK.2020.47.6.568

We propose a new data augmentation method that works by separating the RGB channels of an image to improve image classification ability in uncertain environments. Many data augmentation methods, using technique such as flipping and cropping, have been used to improve the image classification ability of models. while these data augmentation methods have been effective in improving image classification, they have unperformed in uncertain conditions. To solve this problem, we propose the ChannelSplit that separates and reassembles the RGB channels of an image, along with the Mix ChannelSplit, that adopts the concept of MixUp[1,2] to express more diversity. In this paper, the proposed ChannelSplit and Mix ChannelSplit are called ChannelAug because they only utilize channels and do not perform any other image operations. Also, we compare ChannelAug to other image augmentation methods to prove it enhances robustness and uncertainty measures on image classification.


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