• Title/Summary/Keyword: Local feature

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Night-time Vehicle Detection Based On Multi-class SVM (다중-클래스 SVM 기반 야간 차량 검출)

  • Lim, Hyojin;Lee, Heeyong;Park, Ju H.;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.5
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    • pp.325-333
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    • 2015
  • Vision based night-time vehicle detection has been an emerging research field in various advanced driver assistance systems(ADAS) and automotive vehicle as well as automatic head-lamp control. In this paper, we propose night-time vehicle detection method based on multi-class support vector machine(SVM) that consists of thresholding, labeling, feature extraction, and multi-class SVM. Vehicle light candidate blobs are extracted by local mean based thresholding following by labeling process. Seven geometric and stochastic features are extracted from each candidate through the feature extraction step. Each candidate blob is classified into vehicle light or not by multi-class SVM. Four different multi-class SVM including one-against-all(OAA), one-against-one(OAO), top-down tree structured and bottom-up tree structured SVM classifiers are implemented and evaluated in terms of vehicle detection performances. Through the simulations tested on road video sequences, we prove that top-down tree structured and bottom-up tree structured SVM have relatively better performances than the others.

Finger Vein Recognition based on Matching Score-Level Fusion of Gabor Features

  • Lu, Yu;Yoon, Sook;Park, Dong Sun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.2
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    • pp.174-182
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    • 2013
  • Most methods for fusion-based finger vein recognition were to fuse different features or matching scores from more than one trait to improve performance. To overcome the shortcomings of "the curse of dimensionality" and additional running time in feature extraction, in this paper, we propose a finger vein recognition technology based on matching score-level fusion of a single trait. To enhance the quality of finger vein image, the contrast-limited adaptive histogram equalization (CLAHE) method is utilized and it improves the local contrast of normalized image after ROI detection. Gabor features are then extracted from eight channels based on a bank of Gabor filters. Instead of using the features for the recognition directly, we analyze the contributions of Gabor feature from each channel and apply a weighted matching score-level fusion rule to get the final matching score, which will be used for the last recognition. Experimental results demonstrate the CLAHE method is effective to enhance the finger vein image quality and the proposed matching score-level fusion shows better recognition performance.

The Study of Space Organization and Characteristic on Chinese Traditional Courtyard in Pingyao Ancient City

  • Gao, Jie;Zhang, Junhua;Kinoshita, Takeshi
    • Proceedings of the Korean Institute of Landscape Architecture Conference
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    • 2007.10b
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    • pp.162-167
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    • 2007
  • The courtyard life style ever existed as the major traditional living form in wide north China areas. The research made case study and specific analysis on the space organization, constitution and order of the courtyard living, as well as the dwelling accessory manners and transfer space patterns both inside and outside of the courtyard. Pingyao ancient city as the research sample (object), its courtyard composition, classification and characteristic are studied profoundly to explore local traditional cultural traits. On upon the analysis, the research is concluded that the civil courtyard in the ancient Pingyao city bears the feature of in a continuous changing process, which represented as 'from confined to opening', 'from narrow to wide', 'from public to private'. Despite of the courtyard dwelling location and direction, all accessories architectural items on the main room roof were influenced by the geomantic omen culture. As of the inside wall body, entrance and side wall of the courtyard, the woodcraft, stone carving, brick carving on above not only could functioned in architecture artistic, but also express the traditional education spiritual feature.

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A New Image Enhancement Algorithm Based on Bidirectional Diffusion

  • Wang, Zhonghua;Huang, Xiaoming;Huang, Faliang
    • Journal of Information Processing Systems
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    • v.16 no.1
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    • pp.49-60
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    • 2020
  • To solve the edge ringing or block effect caused by the partial differential diffusion in image enhancement domain, a new image enhancement algorithm based on bidirectional diffusion, which smooths the flat region or isolated noise region and sharpens the edge region in different types of defect images on aviation composites, is presented. Taking the image pixel's neighborhood intensity and spatial characteristics as the attribute descriptor, the presented bidirectional diffusion model adaptively chooses different diffusion criteria in different defect image regions, which are elaborated are as follows. The forward diffusion is adopted to denoise along the pixel's gradient direction and edge direction in the pixel's smoothing area while the backward diffusion is used to sharpen along the pixel's gradient direction and the forward diffusion is used to smooth along the pixel's edge direction in the pixel's edge region. The comparison experiments were implemented in the delamination, inclusion, channel, shrinkage, blowhole and crack defect images, and the comparison results indicate that our algorithm not only preserves the image feature better but also improves the image contrast more obviously.

Automated Feature-Based Registration for Reverse Engineering of Human Models

  • Jun, Yong-Tae;Choi, Kui-Won
    • Journal of Mechanical Science and Technology
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    • v.19 no.12
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    • pp.2213-2223
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    • 2005
  • In order to reconstruct a full 3D human model in reverse engineering (RE), a 3D scanner needs to be placed arbitrarily around the target model to capture all part of the scanned surface. Then, acquired multiple scans must be registered and merged since each scanned data set taken from different position is just given in its own local co-ordinate system. The goal of the registration is to create a single model by aligning all individual scans. It usually consists of two sub-steps: rough and fine registration. The fine registration process can only be performed after an initial position is approximated through the rough registration. Hence an automated rough registration process is crucial to realize a completely automatic RE system. In this paper an automated rough registration method for aligning multiple scans of complex human face is presented. The proposed method automatically aligns the meshes of different scans with the information of features that are extracted from the estimated principal curvatures of triangular meshes of the human face. Then the roughly aligned scanned data sets are further precisely enhanced with a fine registration step with the recently popular Iterative Closest Point (ICP) algorithm. Some typical examples are presented and discussed to validate the proposed system.

ASPPMVSNet: A high-receptive-field multiview stereo network for dense three-dimensional reconstruction

  • Saleh Saeed;Sungjun Lee;Yongju Cho;Unsang Park
    • ETRI Journal
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    • v.44 no.6
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    • pp.1034-1046
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    • 2022
  • The learning-based multiview stereo (MVS) methods for three-dimensional (3D) reconstruction generally use 3D volumes for depth inference. The quality of the reconstructed depth maps and the corresponding point clouds is directly influenced by the spatial resolution of the 3D volume. Consequently, these methods produce point clouds with sparse local regions because of the lack of the memory required to encode a high volume of information. Here, we apply the atrous spatial pyramid pooling (ASPP) module in MVS methods to obtain dense feature maps with multiscale, long-range, contextual information using high receptive fields. For a given 3D volume with the same spatial resolution as that in the MVS methods, the dense feature maps from the ASPP module encoded with superior information can produce dense point clouds without a high memory footprint. Furthermore, we propose a 3D loss for training the MVS networks, which improves the predicted depth values by 24.44%. The ASPP module provides state-of-the-art qualitative results by constructing relatively dense point clouds, which improves the DTU MVS dataset benchmarks by 2.25% compared with those achieved in the previous MVS methods.

Modeling Grain Rotational Disruption by Radiative Torques and Extinction of Active Galactic Nuclei

  • Giang, Nguyen Chau;Hoang, Thiem
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.66.1-66.1
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    • 2021
  • Extinction curves observed toward individual Active Galactic Nuclei (AGN) usually show a steep rise toward Far-Ultraviolet (FUV) wavelengths and can be described by the Small Magellanic Cloud (SMC)-like dust model. This feature suggests the dominance of small dust grains of size a < 0.1 ㎛ in the local environment of AGN, but the origin of such small grains is unclear. In this paper, we aim to explain this observed feature by applying the RAdiative Torque Disruption (RATD) to model the extinction of AGN radiation from FUV to Mid-Infrared (MIR) wavelengths. We find that in the intense radiation field of AGN, large composite grains of size a > 0.1 ㎛ are significantly disrupted to smaller sizes by RATD up to dRATD > 100 pc in the polar direction and dRATD ~ 10 pc in the torus region. Consequently, optical-MIR extinction decreases, whereas FUV-near-Ultraviolet extinction increases, producing a steep far-UV rise extinction curve. The resulting total-to selective visual extinction ratio thus significantly drops to RV < 3.1 with decreasing distances to AGN center due to the enhancement of small grains. The dependence of RV with the efficiency of RATD will help us to study the dust properties in the AGN environment via photometric observations. In addition, we suggest that the combination of the strength between RATD and other dust destruction mechanisms that are responsible for destroying very small grains of a <0.05 ㎛ is the key for explaining the dichotomy observed "SMC" and "gray" extinction curve toward many AGN.

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Applications of Machine Learning Models on Yelp Data

  • Ruchi Singh;Jongwook Woo
    • Asia pacific journal of information systems
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    • v.29 no.1
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    • pp.35-49
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    • 2019
  • The paper attempts to document the application of relevant Machine Learning (ML) models on Yelp (a crowd-sourced local business review and social networking site) dataset to analyze, predict and recommend business. Strategically using two cloud platforms to minimize the effort and time required for this project. Seven machine learning algorithms in Azure ML of which four algorithms are implemented in Databricks Spark ML. The analyzed Yelp business dataset contained 70 business attributes for more than 350,000 registered business. Additionally, review tips and likes from 500,000 users have been processed for the project. A Recommendation Model is built to provide Yelp users with recommendations for business categories based on their previous business ratings, as well as the business ratings of other users. Classification Model is implemented to predict the popularity of the business as defining the popular business to have stars greater than 3 and unpopular business to have stars less than 3. Text Analysis model is developed by comparing two algorithms, uni-gram feature extraction and n-feature extraction in Azure ML studio and logistic regression model in Spark. Comparative conclusions have been made related to efficiency of Spark ML and Azure ML for these models.

A Vehicle Detection and Tracking Algorithm Using Local Features of The Vehicle in Tunnel (차량의 부분 특징을 이용한 터널 내에서의 차량 검출 및 추적 알고리즘)

  • Kim, Hyun-Tae;Kim, Gyu-Young;Do, Jin-Kyu;Park, Jang Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1179-1186
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    • 2013
  • In this paper, an efficient vehicle detection and tracking algorithm for detection incident in tunnel is proposed. The proposed algorithm consists of three steps. The first one is a step for background estimates, low computational complexity and memory consumption Running Gaussian Average (RGA) is used. The second step is vehicle detection step, Adaboost algorithm is applied to this step. In order to reduce false detection from a relatively remote location of the vehicles, local features according to height of vehicles are used to detect vehicles. If the local features of an object are more than the threshold value, the object is classified as a vehicle. The last step is a vehicle tracking step, the Kalman filter is applied to track moving objects. Through computer simulations, the proposed algorithm was found that useful to detect and track vehicles in the tunnel.

The Problems of the Social Integration Policy - A Case Study of Social Tolerance Policy in Japan - (일본의 '다문화공생' 정책을 사례로 본 사회통합정책의 과제)

  • Jo, Hyun-Mi
    • Journal of the Korean association of regional geographers
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    • v.15 no.4
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    • pp.449-463
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    • 2009
  • One feature of the multicultural policy practiced in Japan is that the central government stresses the importance of local administrations in executing the policy, providing a systematic framework through which local administrations can actively promote and execute multicultural policy intended to foster social tolerance. In other words, the multicultural policy practiced in Japan seeks to overcome some of the limits and issues inherent to such policy by encouraging the delivery of opinions from below that reflect differences among different localities, while the central government proposes the policy aims and recommendations from above down to local administrations. The multicultural policy of Japan, which allows local administrations to administer such networks by actively carrying out the roles of arbitration and integration within communities where multiculturalism is found, presents meaningful points of comparison and learning to the multicultural policy in Korea that has only recently begun to seek for the aims and ways of multicultural policy from the perspective of social integration.

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