Presentation 2022-06-09
Visualization of decisions from CNN models trained on OpenStreetMap images labeled based on traffic accident data
Kaito Arase, Zhijian Wu, Tsuyoshi Migita, Norikazu Takahashi,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) The authors have recently conducted training of Convolutional Neural Networks (CNNs) on OpenStreetMap images each of which is labeled as ``danger'' or ``safe'' based on traffic accident data. Although the trained CNNs determine whether each area is danger or safe from the map image correctly with a high probability, the reason for this and the basis for their decisions are not clear. In this report, we use a method called Grad-CAM to visualize the basis of CNNs' decisions after learning map images as described above. The visualization result of the Grad-CAM depends on the convolutional layer of the CNN it is applied. The closer the layer is to the output layer, the better the features can be captured, but the resolution of the visualization is lower. Conversely, the closer the layer is to the input layer, the higher the resolution of the visualization, but the less well the features are captured. By analyzing the visualization results of the Grad-CAM for different convolutional layers of different models, we show that there certainly exist convolutional layers suitable for visualization, and clarify some characteristics of the trained CNNs when making their decisions.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) deep learning / map image / OpenStreetMap / Grad-CAM / traffic accident data
Paper # NLP2022-10,CCS2022-10
Date of Issue 2022-06-02 (NLP, CCS)

Conference Information
Committee CCS / NLP
Conference Date 2022/6/9(2days)
Place (in Japanese) (See Japanese page)
Place (in English)
Topics (in Japanese) (See Japanese page)
Topics (in English)
Chair Megumi Akai(Hokkaido Univ.) / Akio Tsuneda(Kumamoto Univ.)
Vice Chair Masaki Aida(TMU) / Hidehiro Nakano(Tokyo City Univ.) / Hiroyuki Torikai(Hosei Univ.)
Secretary Masaki Aida(TDK) / Hidehiro Nakano(Shibaura Insti. of Tech.) / Hiroyuki Torikai(Sojo Univ.)
Assistant Tomoyuki Sasaki(Shonan Instit. of Tech.) / Hiroyasu Ando(Tsukuba Univ.) / Miki Kobayashi(Rissho Univ.) / " Hiroyuki YASUDA(The Univ. of Tokyo) / Yuichi Yokoi(Nagasaki Univ.) / Yoshikazu Yamanaka(Utsunomiya Univ.)

Paper Information
Registration To Technical Committee on Complex Communication Sciences / Technical Committee on Nonlinear Problems
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Visualization of decisions from CNN models trained on OpenStreetMap images labeled based on traffic accident data
Sub Title (in English)
Keyword(1) deep learning
Keyword(2) map image
Keyword(3) OpenStreetMap
Keyword(4) Grad-CAM
Keyword(5) traffic accident data
1st Author's Name Kaito Arase
1st Author's Affiliation Okayama University(Okayama Univ.)
2nd Author's Name Zhijian Wu
2nd Author's Affiliation Okayama University(Okayama Univ.)
3rd Author's Name Tsuyoshi Migita
3rd Author's Affiliation Okayama University(Okayama Univ.)
4th Author's Name Norikazu Takahashi
4th Author's Affiliation Okayama University(Okayama Univ.)
Date 2022-06-09
Paper # NLP2022-10,CCS2022-10
Volume (vol) vol.122
Number (no) NLP-65,CCS-66
Page pp.pp.46-51(NLP), pp.46-51(CCS),
#Pages 6
Date of Issue 2022-06-02 (NLP, CCS)