• Title/Summary/Keyword: Feature space

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Discriminative Power Feature Selection Method for Motor Imagery EEG Classification in Brain Computer Interface Systems

  • Yu, XinYang;Park, Seung-Min;Ko, Kwang-Eun;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.1
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    • pp.12-18
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    • 2013
  • Motor imagery classification in electroencephalography (EEG)-based brain-computer interface (BCI) systems is an important research area. To simplify the complexity of the classification, selected power bands and electrode channels have been widely used to extract and select features from raw EEG signals, but there is still a loss in classification accuracy in the state-of- the-art approaches. To solve this problem, we propose a discriminative feature extraction algorithm based on power bands with principle component analysis (PCA). First, the raw EEG signals from the motor cortex area were filtered using a bandpass filter with ${\mu}$ and ${\beta}$ bands. This research considered the power bands within a 0.4 second epoch to select the optimal feature space region. Next, the total feature dimensions were reduced by PCA and transformed into a final feature vector set. The selected features were classified by applying a support vector machine (SVM). The proposed method was compared with a state-of-art power band feature and shown to improve classification accuracy.

Improved Feature Selection Techniques for Image Retrieval based on Metaheuristic Optimization

  • Johari, Punit Kumar;Gupta, Rajendra Kumar
    • International Journal of Computer Science & Network Security
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    • v.21 no.1
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    • pp.40-48
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    • 2021
  • Content-Based Image Retrieval (CBIR) system plays a vital role to retrieve the relevant images as per the user perception from the huge database is a challenging task. Images are represented is to employ a combination of low-level features as per their visual content to form a feature vector. To reduce the search time of a large database while retrieving images, a novel image retrieval technique based on feature dimensionality reduction is being proposed with the exploit of metaheuristic optimization techniques based on Genetic Algorithm (GA), Extended Binary Cuckoo Search (EBCS) and Whale Optimization Algorithm (WOA). Each image in the database is indexed using a feature vector comprising of fuzzified based color histogram descriptor for color and Median binary pattern were derived in the color space from HSI for texture feature variants respectively. Finally, results are being compared in terms of Precision, Recall, F-measure, Accuracy, and error rate with benchmark classification algorithms (Linear discriminant analysis, CatBoost, Extra Trees, Random Forest, Naive Bayes, light gradient boosting, Extreme gradient boosting, k-NN, and Ridge) to validate the efficiency of the proposed approach. Finally, a ranking of the techniques using TOPSIS has been considered choosing the best feature selection technique based on different model parameters.

Centroid Neural Network with Bhattacharyya Kernel (Bhattacharyya 커널을 적용한 Centroid Neural Network)

  • Lee, Song-Jae;Park, Dong-Chul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.9C
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    • pp.861-866
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    • 2007
  • A clustering algorithm for Gaussian Probability Distribution Function (GPDF) data called Centroid Neural Network with a Bhattacharyya Kernel (BK-CNN) is proposed in this paper. The proposed BK-CNN is based on the unsupervised competitive Centroid Neural Network (CNN) and employs a kernel method for data projection. The kernel method adopted in the proposed BK-CNN is used to project data from the low dimensional input feature space into higher dimensional feature space so as the nonlinear problems associated with input space can be solved linearly in the feature space. In order to cluster the GPDF data, the Bhattacharyya kernel is used to measure the distance between two probability distributions for data projection. With the incorporation of the kernel method, the proposed BK-CNN is capable of dealing with nonlinear separation boundaries and can successfully allocate more code vector in the region that GPDF data are densely distributed. When applied to GPDF data in an image classification probleml, the experiment results show that the proposed BK-CNN algorithm gives 1.7%-4.3% improvements in average classification accuracy over other conventional algorithm such as k-means, Self-Organizing Map (SOM) and CNN algorithms with a Bhattacharyya distance, classed as Bk-Means, B-SOM, B-CNN algorithms.

A Study on the Base Material Specific and Processing Methods of Recycled New Materials in Space (실내공간에 사용되는 재활용 신재료의 소재 및 가공방법 연구)

  • Seo, Ji-Eun;Jeong, Hee-Jeong
    • Korean Institute of Interior Design Journal
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    • v.21 no.3
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    • pp.22-30
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    • 2012
  • Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

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Defect evaluations of weld zone in rails considering phase space-frequency demain (위상공간-주파수 영역을 고려한 레일 용접부의 결함 평가)

  • 윤인식;권성태;장영권;정우현;이찬석
    • Journal of the Korean Society for Railway
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    • v.2 no.2
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    • pp.21-30
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    • 1999
  • This study proposes the analysis and evaluation method of time series ultrasonic signal using the phase space-frequency domain. Features extracted from time series signal analyze quantitatively characteristics of weld defects. For this purpose, analysis objectives in this study are features of time domain and frequency domain. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange even though the types of defects are identified. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hole) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimension. Proposed phase space-frequency domain method in this study can integrity evaluation for defect signals of rail weld zone such as side hole and crack.

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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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Video Mosaics in 3D Space

  • Chon, Jaechoon;Fuse, Takashi;Shimizu, Eihan
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.390-392
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    • 2003
  • Video mosaicing techniques have been widely used in virtual reality environments. Especially in GIS field, video mosaics are becoming more and more common in representing urban environments. Such applications mainly use spherical or panoramic mosaics that are based on images taken from a rotating camera around its nodal point. The viewpoint, however, is limited to location within a small area. On the other hand, 2D-mosaics, which are based on images taken from a translating camera, can acquire data in wide area. The 2D-mosaics still have some problems : it can‘t be applied to images taken from a rotational camera in large angle. To compensate those problems , we proposed a novel method for creating video mosaics in 3D space. The proposed algorithm consists of 4 steps: feature -based optical flow detection, camera orientation, 2D-image projection, and image registration in 3D space. All of the processes are fully automatic and successfully implemented and tested with real images.

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IGRINS NIR Spectroscopy of Diffuse Sources around MWC 1080

  • Kim, Il-Joong;Oh, Heeyoung;Jeong, Woong-Seob;Lee, Jae-Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.48.1-48.1
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    • 2019
  • We found a diffuse Hα feature with a large size of ~2' around a Herbig star, MWC 1080. It shows a strong correlation with the elongated outflow cavity centered on the star. To investigate the diffuse Hα source and the molecular cavity in detail, we carried out the high-resolution NIR spectroscopy using IGRINS. We detected six hydrogen Brackett line series, seven H2 lines, and an [Fe II] forbidden line. With the obtained spatial, kinematic, and line ratio results, we discuss the characteristics of the central MWC 1080A, the NE outflow cavity, and the SE molecular cloud regions separately. Most of the bright Brγ sources around MWC 1080A were found to be reflection nebulae, but a point-like Brγ source close to another young star, MWC 1080E, was identified as a distinct source due to MWC 1080E itself. The narrow components of the H2 lines observed around MWC 1080A were found to trace PDRs located on the wall of the main outflow cavity. Based on the shock-excited H2 and [Fe II] lines detected just inside a bow-shock shape Hα feature, we suggest that it represents the actual shock at the head of the NE outflow from MWC 1080A. Also, we newly detected the shock-excited H2 and [Fe II] lines with highly blueshifted velocities in the SE molecular cloud region. They could be related to unrevealed outflows from other young stars existing around MWC 1080A.

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A Facial Feature Area Extraction Method for Improving Face Recognition Rate in Camera Image (일반 카메라 영상에서의 얼굴 인식률 향상을 위한 얼굴 특징 영역 추출 방법)

  • Kim, Seong-Hoon;Han, Gi-Tae
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.5
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    • pp.251-260
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    • 2016
  • Face recognition is a technology to extract feature from a facial image, learn the features through various algorithms, and recognize a person by comparing the learned data with feature of a new facial image. Especially, in order to improve the rate of face recognition, face recognition requires various processing methods. In the training stage of face recognition, feature should be extracted from a facial image. As for the existing method of extracting facial feature, linear discriminant analysis (LDA) is being mainly used. The LDA method is to express a facial image with dots on the high-dimensional space, and extract facial feature to distinguish a person by analyzing the class information and the distribution of dots. As the position of a dot is determined by pixel values of a facial image on the high-dimensional space, if unnecessary areas or frequently changing areas are included on a facial image, incorrect facial feature could be extracted by LDA. Especially, if a camera image is used for face recognition, the size of a face could vary with the distance between the face and the camera, deteriorating the rate of face recognition. Thus, in order to solve this problem, this paper detected a facial area by using a camera, removed unnecessary areas using the facial feature area calculated via a Gabor filter, and normalized the size of the facial area. Facial feature were extracted through LDA using the normalized facial image and were learned through the artificial neural network for face recognition. As a result, it was possible to improve the rate of face recognition by approx. 13% compared to the existing face recognition method including unnecessary areas.

A Study on the Contents to Vitalize the Space for Making Traditional Gwangheemun A Tourism Resource (문화유산 광희문(光熙門)의 관광자원화를 위한 공간 활성화 콘텐츠 연구)

  • Kim, Ji Eun;Park, Eun Soo
    • Korea Science and Art Forum
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    • v.23
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    • pp.95-109
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    • 2016
  • The background and objective of this study are as follows. Gwangheemun, one of the 4 small gates of Seoul Castle is a space to represent ordinary people and it is a valuable cultural heritage that shows the process of technical transition of fortification technology during Chosun Dynasty. It is a place that we can expect to play a role as a field where history and culture mix and communicate together. But currently, the environment and facilities around Gwangheemun have fallen behind and become old, so they need to be reorganized as their local feature is not shown distinctly. We need to vitalize the new traditional space that shows local feature. This study has drawn out the method, contents and the result of study like as follows. This study aims to establish an identity based on the historical and cultural backgrounds and suggest the contents to vitalize the space of Gwangheemun as a traditional cultural heritage. By this, this study aims to create a historical and cultural space where people can enjoy, eat and look around. Therefore, based on the historical and cultural feature, it gives an identity as moonlight street, and it has developed and suggested 5 contents to vitalize space: Gwangheemun maintenance, plan, castle restoration plan, village inside the castle, village outside the castle and fashion art street. Contents to vitalize space has a meaning as a specific developmen method of urban restoration, and we can expect to be used as a direction to develop the area to enhance the cultural quality of life of both inhabitants and visitors by forming the brand identity of surrounding area with traditional cultural heritage.