• Title/Summary/Keyword: local feature extraction

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A Dual-scale Network with Spatial-temporal Attention for 12-lead ECG Classification

  • Shuo Xiao;Yiting Xu;Chaogang Tang;Zhenzhen Huang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.9
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    • pp.2361-2376
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    • 2023
  • The electrocardiogram (ECG) signal is commonly used to screen and diagnose cardiovascular diseases. In recent years, deep neural networks have been regarded as an effective way for automatic ECG disease diagnosis. The convolutional neural network is widely used for ECG signal extraction because it can obtain different levels of information. However, most previous studies adopt single scale convolution filters to extract ECG signal features, ignoring the complementarity between ECG signal features of different scales. In the paper, we propose a dual-scale network with convolution filters of different sizes for 12-lead ECG classification. Our model can extract and fuse ECG signal features of different scales. In addition, different spatial and time periods of the feature map obtained from the 12-lead ECG may have different contributions to ECG classification. Therefore, we add a spatial-temporal attention to each scale sub-network to emphasize the representative local spatial and temporal features. Our approach is evaluated on PTB-XL dataset and achieves 0.9307, 0.8152, and 89.11 on macro-averaged ROC-AUC score, a maximum F1 score, and mean accuracy, respectively. The experiment results have proven that our approach outperforms the baselines.

An Explainable Deep Learning-Based Classification Method for Facial Image Quality Assessment

  • Kuldeep Gurjar;Surjeet Kumar;Arnav Bhavsar;Kotiba Hamad;Yang-Sae Moon;Dae Ho Yoon
    • Journal of Information Processing Systems
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    • v.20 no.4
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    • pp.558-573
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    • 2024
  • Considering factors such as illumination, camera quality variations, and background-specific variations, identifying a face using a smartphone-based facial image capture application is challenging. Face Image Quality Assessment refers to the process of taking a face image as input and producing some form of "quality" estimate as an output. Typically, quality assessment techniques use deep learning methods to categorize images. The models used in deep learning are shown as black boxes. This raises the question of the trustworthiness of the models. Several explainability techniques have gained importance in building this trust. Explainability techniques provide visual evidence of the active regions within an image on which the deep learning model makes a prediction. Here, we developed a technique for reliable prediction of facial images before medical analysis and security operations. A combination of gradient-weighted class activation mapping and local interpretable model-agnostic explanations were used to explain the model. This approach has been implemented in the preselection of facial images for skin feature extraction, which is important in critical medical science applications. We demonstrate that the use of combined explanations provides better visual explanations for the model, where both the saliency map and perturbation-based explainability techniques verify predictions.

A label-free high precision automated crack detection method based on unsupervised generative attentional networks and swin-crackformer

  • Shiqiao Meng;Lezhi Gu;Ying Zhou;Abouzar Jafari
    • Smart Structures and Systems
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    • v.33 no.6
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    • pp.449-463
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    • 2024
  • Automated crack detection is crucial for structural health monitoring and post-earthquake rapid damage detection. However, realizing high precision automatic crack detection in the absence of corresponding manual labeling presents a formidable challenge. This paper presents a novel crack segmentation transfer learning method and a novel crack segmentation model called Swin-CrackFormer. The proposed method facilitates efficient crack image style transfer through a meticulously designed data preprocessing technique, followed by the utilization of a GAN model for image style transfer. Moreover, the proposed Swin-CrackFormer combines the advantages of Transformer and convolution operations to achieve effective local and global feature extraction. To verify the effectiveness of the proposed method, this study validates the proposed method on three unlabeled crack datasets and evaluates the Swin-CrackFormer model on the METU dataset. Experimental results demonstrate that the crack transfer learning method significantly improves the crack segmentation performance on unlabeled crack datasets. Moreover, the Swin-CrackFormer model achieved the best detection result on the METU dataset, surpassing existing crack segmentation models.

Recognition and Modeling of 3D Environment based on Local Invariant Features (지역적 불변특징 기반의 3차원 환경인식 및 모델링)

  • Jang, Dae-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.3
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    • pp.31-39
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    • 2006
  • This paper presents a novel approach to real-time recognition of 3D environment and objects for various applications such as intelligent robots, intelligent vehicles, intelligent buildings,..etc. First, we establish the three fundamental principles that humans use for recognizing and interacting with the environment. These principles have led to the development of an integrated approach to real-time 3D recognition and modeling, as follows: 1) It starts with a rapid but approximate characterization of the geometric configuration of workspace by identifying global plane features. 2) It quickly recognizes known objects in environment and replaces them by their models in database based on 3D registration. 3) It models the geometric details the geometric details on the fly adaptively to the need of the given task based on a multi-resolution octree representation. SIFT features with their 3D position data, referred to here as stereo-sis SIFT, are used extensively, together with point clouds, for fast extraction of global plane features, for fast recognition of objects, for fast registration of scenes, as well as for overcoming incomplete and noisy nature of point clouds.

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Prostate Object Extraction in Ultrasound Volume Using Wavelet Transform (초음파 볼륨에서 웨이브렛 변환을 이용한 전립선 객체 추출)

  • Oh Jong-Hwan;Kim Sang-Hyun;Kim Nam-Chul
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.3 s.309
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    • pp.67-77
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    • 2006
  • This thesis proposes an effi챠ent method for extracting a prostate volume from 3D ultrasound image by using wavelet transform and SVM classification. In the proposed method, a modulus image for each 2D slice is generated by averaging detail images of horizontal and vertical orientations at several scales, which has the sharpest local maxima and the lowest noise power compared to those of all single scales. Prostate contour vertices are determined accurately using a SVM classifier, where feature vectors are composed of intensity and texture moments investigated along radial lines. Experimental results show that the proposed method yields absolute mean distance of on average 1.89 pixels when the contours obtained manually by an expert are used as reference data.

Feature Extraction based FE-SONN for Signature Verification (서명 검증을 위한 특정 기반의 FE-SONN)

  • Koo Gun-Seo
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.93-102
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    • 2005
  • This paper proposes an approach to verify signature using autonomous self-organized Neural Network Model , fused with fuzzy membership equation of fuzzy c-means algorithm, based on the features of the signature. To overcome limitations of the functional approach and Parametric approach among the conventional on-line signature recognition approaches, this Paper presents novel autonomous signature classification approach based on clustering features. Thirty-six globa1 features and twelve local features were defined, so that a signature verifying system with FE-SONN that learns them was implemented. It was experimented for total 713 signatures that are composed of 155 original signatures and 180 forged signatures yet 378 original signatures written by oneself. The success rate of this test is more than 97.67$\%$ But, a few forged signatures that could not be detected by human eyes could not be done by the system either.

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Steganalysis of Content-Adaptive Steganography using Markov Features for DCT Coefficients (DCT 계수의 마코프 특징을 이용한 내용 적응적 스테가노그래피의 스테그분석)

  • Park, Tae Hee;Han, Jong Goo;Eom, Il Kyu
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.8
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    • pp.97-105
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    • 2015
  • Content-adaptive steganography methods embed secret messages in hard-to-model regions of covers such as complicated texture or noisy area. Content-adaptive steganalysis methods often need high dimensional features to capture more subtle relationships of local dependencies among adjacent pixels. However, these methods require many computational complexity and depend on the location of hidden message and the exploited distortion metrics. In this paper, we propose an improved steganalysis method for content-adaptive steganography to enhance detection rate with small number features. We first show that the features form the difference between DCT coefficients are useful for analyzing the content-adaptive steganography methods, and present feature extraction mehtod using first-order Markov probability for the the difference between DCT coefficients. The extracted features are used as input of ensemble classifier. Experimental results show that the proposed method outperforms previous schemes in terms of detection rates and accuracy in spite of a small number features in various content-adaptive stego images.

CLINICAL CHARACTERIZATION OF THE MAXILLARY SINUS ASPERGILLOSIS (상악동 국균증의 임상적 특성)

  • Choi, Hee-Soo;Yoon, Jung-Hoon;Kim, Hyung-Jun;Cha, In-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.3
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    • pp.271-275
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    • 2001
  • Nine cases of maxillary sinus aspergillosis during a period from February of 1992 to June of 2000 were investigated to analyze the clinical, radiologic and pathologic features. Maxillary sinus aspergillosis is rare disease, but it was increasing tendency with overuse antibiotics, steroid hormones, and anticancer agents. Aspergillosis of the maxillary sinus may occur as a chronic disease in an otherwise healthy person. The clinical features of maxillary sinus aspergillosis were similar to the non-fungal, chronic sinusitis. Intrasinus calcification is known to be a characteristic feature of maxillary sinus aspergillosis. It is suggested that excess root filling materials containing zinc oxide in the maxillary sinus could favour the formation of a local, non-invasive maxillary sinus aspergillosis. And this "dental" model of pathogenensis of maxillary sinus aspergillosis is an alternative to the widely accepted concept of spore inhalation and "aero-genic" pathogenensis of maxillary sinus aspergillosis. The radical surgery such as Caldwell-Luc operation was one of the most effective treatment modalities. Our results of this study indicate that maxillary sinus aspergillosis might occur mainly in healthy individuals rather than debilitating patients. It could efficiently treated with radical surgery alone without the antifungal agents. 4 cases were suspected to be related with teeth extraction and endodontic treatment. There were no recurrence in all cases.

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Land Use Feature Extraction and Sprawl Development Prediction from Quickbird Satellite Imagery Using Dempster-Shafer and Land Transformation Model

  • Saharkhiz, Maryam Adel;Pradhan, Biswajeet;Rizeei, Hossein Mojaddadi;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.36 no.1
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    • pp.15-27
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    • 2020
  • Accurate knowledge of land use/land cover (LULC) features and their relative changes over upon the time are essential for sustainable urban management. Urban sprawl growth has been always also a worldwide concern that needs to carefully monitor particularly in a developing country where unplanned building constriction has been expanding at a high rate. Recently, remotely sensed imageries with a very high spatial/spectral resolution and state of the art machine learning approaches sent the urban classification and growth monitoring to a higher level. In this research, we classified the Quickbird satellite imagery by object-based image analysis of Dempster-Shafer (OBIA-DS) for the years of 2002 and 2015 at Karbala-Iraq. The real LULC changes including, residential sprawl expansion, amongst these years, were identified via change detection procedure. In accordance with extracted features of LULC and detected trend of urban pattern, the future LULC dynamic was simulated by using land transformation model (LTM) in geospatial information system (GIS) platform. Both classification and prediction stages were successfully validated using ground control points (GCPs) through accuracy assessment metric of Kappa coefficient that indicated 0.87 and 0.91 for 2002 and 2015 classification as well as 0.79 for prediction part. Detail results revealed a substantial growth in building over fifteen years that mostly replaced by agriculture and orchard field. The prediction scenario of LULC sprawl development for 2030 revealed a substantial decline in green and agriculture land as well as an extensive increment in build-up area especially at the countryside of the city without following the residential pattern standard. The proposed method helps urban decision-makers to identify the detail temporal-spatial growth pattern of highly populated cities like Karbala. Additionally, the results of this study can be considered as a probable future map in order to design enough future social services and amenities for the local inhabitants.

Mobile Phone Camera Based Scene Text Detection Using Edge and Color Quantization (에지 및 컬러 양자화를 이용한 모바일 폰 카메라 기반장면 텍스트 검출)

  • Park, Jong-Cheon;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.3
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    • pp.847-852
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    • 2010
  • Text in natural images has a various and important feature of image. Therefore, to detect text and extraction of text, recognizing it is a studied as an important research area. Lately, many applications of various fields is being developed based on mobile phone camera technology. Detecting edge component form gray-scale image and detect an boundary of text regions by local standard deviation and get an connected components using Euclidean distance of RGB color space. Labeling the detected edges and connected component and get bounding boxes each regions. Candidate of text achieved with heuristic rule of text. Detected candidate text regions was merged for generation for one candidate text region, then text region detected with verifying candidate text region using ectilarity characterization of adjacency and ectilarity between candidate text regions. Experctental results, We improved text region detection rate using completentary of edge and color connected component.