• 제목/요약/키워드: feature value

검색결과 1,168건 처리시간 0.025초

Improving the Performance of a Fast Text Classifier with Document-side Feature Selection (문서측 자질선정을 이용한 고속 문서분류기의 성능향상에 관한 연구)

  • Lee, Jae-Yun
    • Journal of Information Management
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    • 제36권4호
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    • pp.51-69
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    • 2005
  • High-speed classification method becomes an important research issue in text categorization systems. A fast text categorization technique, named feature value voting, is introduced recently on the text categorization problems. But the classification accuracy of this technique is not good as its classification speed. We present a novel approach for feature selection, named document-side feature selection, and apply it to feature value voting method. In this approach, there is no feature selection process in learning phase; but realtime feature selection is executed in classification phase. Our results show that feature value voting with document-side feature selection can allow fast and accurate text classification system, which seems to be competitive in classification performance with Support Vector Machines, the state-of-the-art text categorization algorithms.

Adaptive Shot Change Detection using Mean of Feature Value on Variable Reference Blocks and Implementation on PMP

  • Kim, Jong-Nam;Kim, Won-Hee
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.229-232
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    • 2009
  • Shot change detection is an important technique for effective management of video data, so detection scheme requires adaptive detection techniques to be used actually in various video. In this paper, we propose an adaptive shot change detection algorithm using the mean of feature value on variable reference blocks. Our algorithm determines shot change detection by defining adaptive threshold values with the feature value extracted from video frames and comparing the feature value and the threshold value. We obtained better detection ratio than the conventional methods maximally by 15% in the experiment with the same test sequence. We also had good detection ratio for other several methods of feature extraction and could see real-time operation of shot change detection in the hardware platform with low performance was possible by implementing it in TVUS model of HOMECAST Company. Thus, our algorithm in the paper can be useful in PMP or other portable players.

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Evaluating the Contribution of Spectral Features to Image Classification Using Class Separability

  • Ye, Chul-Soo
    • Korean Journal of Remote Sensing
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    • 제36권1호
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    • pp.55-65
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    • 2020
  • Image classification needs the spectral similarity comparison between spectral features of each pixel and the representative spectral features of each class. The spectral similarity is obtained by computing the spectral feature vector distance between the pixel and the class. Each spectral feature contributes differently in the image classification depending on the class separability of the spectral feature, which is computed using a suitable vector distance measure such as the Bhattacharyya distance. We propose a method to determine the weight value of each spectral feature in the computation of feature vector distance for the similarity measurement. The weight value is determined by the ratio between each feature separability value to the total separability values of all the spectral features. We created ten spectral features consisting of seven bands of Landsat-8 OLI image and three indices, NDVI, NDWI and NDBI. For three experimental test sites, we obtained the overall accuracies between 95.0% and 97.5% and the kappa coefficients between 90.43% and 94.47%.

Comparing Korean Spam Document Classification Using Document Classification Algorithms (문서 분류 알고리즘을 이용한 한국어 스팸 문서 분류 성능 비교)

  • Song, Chull-Hwan;Yoo, Seong-Joon
    • Proceedings of the Korean Information Science Society Conference
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    • 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (C)
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    • pp.222-225
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    • 2006
  • 한국은 다른 나라에 비해 많은 인터넷 사용자를 가지고 있다. 이에 비례해서 한국의 인터넷 유저들은 Spam Mail에 대해 많은 불편함을 호소하고 있다. 이러한 문제를 해결하기 위해 본 논문은 다양한 Feature Weighting, Feature Selection 그리고 문서 분류 알고리즘들을 이용한 한국어 스팸 문서 Filtering연구에 대해 기술한다. 그리고 한국어 문서(Spam/Non-Spam 문서)로부터 영사를 추출하고 이를 각 분류 알고리즘의 Input Feature로써 이용한다. 그리고 우리는 Feature weighting 에 대해 기존의 전통적인 방법이 아니라 각 Feature에 대해 Variance 값을 구하고 Global Feature를 선택하기 위해 Max Value Selection 방법에 적용 후에 전통적인 Feature Selection 방법인 MI, IG, CHI 들을 적용하여 Feature들을 추출한다. 이렇게 추출된 Feature들을 Naive Bayes, Support Vector Machine과 같은 분류 알고리즘에 적용한다. Vector Space Model의 경우에는 전통적인 방법 그대로 사용한다. 그 결과 우리는 Support Vector Machine Classifier, TF-IDF Variance Weighting(Combined Max Value Selection), CHI Feature Selection 방법을 사용할 경우 Recall(99.4%), Precision(97.4%), F-Measure(98.39%)의 성능을 보였다.

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Phonological Characteristics of Russian Nasal Consonants (러시아어 비음의 음운적 특성)

  • Kim, Shin-Hyo
    • Cross-Cultural Studies
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    • 제39권
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    • pp.381-406
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    • 2015
  • Russian nasal consonants / m /, / n / have a feature value not only [+consonant] in common with obstruents, but also [+sonorant] in common with vowels. Nasal / m /(bi-labial) and / n /(dental) have the same place of articulation but different manner of articulation. The feature value of / m / is [+cons, +son, +nas, +ant, -cor, -high, -low, -back, -cont, -del, rel, -strid, +voic], and that of / n / is [+cons, +son, +nas, +ant, +cor, -high, -low, -back, -cont, -del, rel, -strid, + voic]. There is a difference in feature [cor] value of / m / and / n /. In this study it is confirmed that it is a fact that the Russian nasal consonants behave differently from the other consonants in each phonological phenomenon due to their phonological characteristics. The preceding voiced obstruent is changed to an unvoiced one in a process where the last voiceless obstruent in the consonant cluster ' voiced obstruent + nasal /m/ + voiceless obstruent' skips the nasal consonant and spreads its feature value to the preceding voiced obstruent transparently because of the feature [+sonorant] of the nasal consonant. The coronal nasal /n/ participates in a palatalization with the following palatal actively and palatalize preceding plain consonants passively because of markedness hierarchy such as 'Velar > Labial > Coronal'. But the labial nasal /m/ is palatalized with the following velar palatal actively and participates in a palatalization with the following coronal palatal passively. This result helps us confirm the phonological difference of /m/ and /n/ in a palatalization. When the a final consonant is nasal, the unvoicing phenomenon of a final consonant doesn't occur. In such a case as cluster 'obstruent + nasal' the feature value [voiced] of the preceding obstruent doesn't change, but the following nasal can assimilate into the preceding obstruent. When continuing the same nasals / -nn- / in a consonant cluster, the feature value [+cont] of a weak position leads the preceding nasal / n / to be changed into [-cont] / l /. Through the analysis of the frequency of occurrences of consonants in syllabic onsets and codas that should observe the 'Sonority Sequence Principle', the sonority hierarchy of nasal consonants has been confirmed. In a diachronic perspective following nasal / m /, / n / there is a loss of the preceding labial stop and dental stop. But in clusters with the velar stop+nasal, the two-component cluster has been kept phonetically intact.

Factors Influencing Experiential Value Toward Using Cosmetic AR Try-on Feature in Thailand

  • VONGURAI, Rawin
    • Journal of Distribution Science
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    • 제19권1호
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    • pp.75-87
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    • 2021
  • Purpose: The objective of this research is to identify the core aspects of persuasive factors influencing consumer's experiential value towards using Augmented Reality (AR) try-on feature while shopping cosmetic products online. The conceptual framework of this study is adopted and integrated from the theoretical study on how narrative experience, media richness, and presence affect the formation of experiential value in the augmented reality interactive technology (ARIT) process. Research design, data and methodology: The sample (n = 550) were collected from online and offline questionnaires by using stratified random sampling and purposive sampling methods. Confirmatory Factor Analysis (CFA) and Structural Equation Model (SEM) were used to analyze the data to confirm goodness-of-fit of the model and hypothesis testing. Results: The results indicated that media richness induced higher experiential value (consumer ROI, playfulness, service excellence and aesthetics), followed by narrative experience and presence towards using AR try-on feature. Conclusions: Consumer's experiential value towards using AR try-on feature when shopping cosmetic products online rely on media richness, narrative experience and presence respectively. Therefore, marketing practitioners are recommended to develop the feature design and content to be more useful, authentic, user-friendly and entertaining to better connect and provide confidence to consumers when shopping cosmetics online.

카메라 디포커싱을 이용한 로보트의 시각 서보

  • 신진우;고국현;조형석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 1994년도 추계학술대회 논문집
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    • pp.559-564
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    • 1994
  • Recently, a visual servoing for an eye-in-hand robot has become an interesting problem. A distance between a camera and a task object is very useful information for visual servoing. In the previous works for visual servoing, the distance can be obtained from the difference between a reference and a measured feature value of the object such as area on image plane. However, since this feature depends on the object, the reference feature value must be changed when other task object is taken. To overcome this difficulty, this paper presents a novel method for visual servoing. In the proposed method, a blur is used to obtain the distance. The blur, one of the most important features, depends on the focal length of camera. Since it is not affected by the change of object, the reference feature value is not changed although other task object is taken. In this paper, we show a relationship between the distance and the blur, and define the feature jacobian matrix based on camera defocusing to operate the robot. A series of experiments is performed to verify the proposed method.

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Face Feature Extraction Method ThroughStereo Image's Matching Value (스테레오 영상의 정합값을 통한 얼굴특징 추출 방법)

  • Kim, Sang-Myung;Park, Chang-Han;Namkung, Jae-Chan
    • Journal of Korea Multimedia Society
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    • 제8권4호
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    • pp.461-472
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    • 2005
  • In this paper, we propose face feature extraction algorithm through stereo image's matching value. The proposed algorithm detected face region by change the RGB color space of skin color information to the YCbCr color space. Applying eye-template from extracted face region geometrical feature vector of feature about distance and lean, nose and mouth between eye extracted. And, Proposed method could do feature of eyes, nose and mouth through stereo image's matching as well as 2D feature information extract. In the experiment, the proposed algorithm shows the consistency rate of 73% in distance within about 1m and the consistency rate of 52%in distance since about 1m.

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Stereo Matching Method using Directional Feature Vector (방향성 특징벡터를 이용한 스테레오 정합 기법)

  • Moon, Chang-Gi;Jeon, Jong-Hyun;Ye, Chul-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • 제13권1호
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    • pp.52-57
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    • 2007
  • In this paper we proposed multi-directional matching windows combined by multi-dimensional feature vector matching, which uses not only intensity values but also multiple feature values, such as variance, first and second derivative of pixels. Multi-dimensional feature vector matching has the advantage of compensating the drawbacks of area-based stereo matching using one feature value, such as intensity. We define matching cost of a pixel by the minimum value among eight multi-dimensional feature vector distances of the pixels expanded in eight directions having the interval of 45 degrees. As best stereo matches, we determine the two points with the minimum matching cost within the disparity range. In the experiment we used aerial imagery and IKONOS satellite imagery and obtained more accurate matching results than that of conventional matching method.

Security Analysis based on Differential Entropy m 3D Model Hashing (3D 모델 해싱의 미분 엔트로피 기반 보안성 분석)

  • Lee, Suk-Hwan;Kwon, Ki-Ryong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제35권12C호
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    • pp.995-1003
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    • 2010
  • The content-based hashing for authentication and copy protection of image, video and 3D model has to satisfy the robustness and the security. For the security analysis of the hash value, the modelling method based on differential entropy had been presented. But this modelling can be only applied to the image hashing. This paper presents the modelling for the security analysis of the hash feature value in 3D model hashing based on differential entropy. The proposed security analysis modeling design the feature extracting methods of two types and then analyze the security of two feature values by using differential entropy modelling. In our experiment, we evaluated the security of feature extracting methods of two types and discussed about the trade-off relation of the security and the robustness of hash value.