• 제목/요약/키워드: Statistical descriptors

검색결과 39건 처리시간 0.027초

기하학적 변수에 의한 다이옥신의 독성 예측 (Estimation of Biological Action of Dioxins by Some Geometric Descriptors)

  • Hwang, Inchul
    • Environmental Analysis Health and Toxicology
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    • 제14권3호
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    • pp.103-111
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    • 1999
  • To effectively predict the lipophilicity, the aryl hydrocarbon receptor (AhR) affinity, and TEF (Toxic equivalency factor) of dioxins by geometrical descriptors, the multiple linear regression methods with the forward selection and backward elimination were employed with statistical validity. The lipophilicity, the Ah receptor binding affinity, and the toxic equivalency factor of dioxins could be predicted using some geometrical descriptors.

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Image Registration Based On Statistical Descriptors In Frequency Domain

  • Chang, Min-hyuk;Ahmad, Muhammad-Bilal;Lee, Cheul-hee;Chun, Jong-hoon;Park, Seung-jin;Park, Jong-an
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -3
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    • pp.1531-1534
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    • 2002
  • Shape description and its corresponding matching algorithm is one of the main concerns in MPEG-7. In this paper, a new method is proposed for shape registration of 2D objects for MPEG-7 Shapes are recognized using the Hu statistical moments in frequency domain. The Hu moments are moment-based descriptors of planar shapes, which are invariant under general translation, rotational, scaling, and reflection transformation. The image is transformed into frequency domain using Fourier Transform. Annular and radial wedge distributions fur the power spectra are extracted. Different statistical features (Hu moments) are found f3r the power spectrum of each selected transformed individual feature. The Euclidean distance of the extracted moment descriptors of the features are found with respect to the shapes in the database. The minimum Euclidean distance is the candidate for the matched shape. The simulation results are performed on the test shapes of MPEG-7.

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Is it Possible to Predict the ADI of Pesticides using the QSAR Approach?

  • Kim, Jae Hyoun
    • 한국환경보건학회지
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    • 제38권6호
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    • pp.550-560
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    • 2012
  • Objectives: QSAR methodology was applied to explain two different sets of acceptable daily intake (ADI) data of 74 pesticides proposed by both the USEPA and WHO in terms of setting guidelines for food and drinking water. Methods: A subset of calculated descriptors was selected from Dragon$^{(R)}$ software. QSARs were then developed utilizing a statistical technique, genetic algorithm-multiple linear regression (GA-MLR). The differences in each specific model in the prediction of the ADI of the pesticides were discussed. Results: The stepwise multiple linear regression analysis resulted in a statistically significant QSAR model with five descriptors. Resultant QSAR models were robust, showing good utility across multiple classes of pesticide compounds. The applicability domain was also defined. The proposed models were robust and satisfactory. Conclusions: The QSAR model could be a feasible and effective tool for predicting ADI and for the comparison of logADIEPA to logADIWHO. The statistical results agree with the fact that USEPA focuses on more subtle endpoints than does WHO.

Evaluation of Histograms Local Features and Dimensionality Reduction for 3D Face Verification

  • Ammar, Chouchane;Mebarka, Belahcene;Abdelmalik, Ouamane;Salah, Bourennane
    • Journal of Information Processing Systems
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    • 제12권3호
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    • pp.468-488
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    • 2016
  • The paper proposes a novel framework for 3D face verification using dimensionality reduction based on highly distinctive local features in the presence of illumination and expression variations. The histograms of efficient local descriptors are used to represent distinctively the facial images. For this purpose, different local descriptors are evaluated, Local Binary Patterns (LBP), Three-Patch Local Binary Patterns (TPLBP), Four-Patch Local Binary Patterns (FPLBP), Binarized Statistical Image Features (BSIF) and Local Phase Quantization (LPQ). Furthermore, experiments on the combinations of the four local descriptors at feature level using simply histograms concatenation are provided. The performance of the proposed approach is evaluated with different dimensionality reduction algorithms: Principal Component Analysis (PCA), Orthogonal Locality Preserving Projection (OLPP) and the combined PCA+EFM (Enhanced Fisher linear discriminate Model). Finally, multi-class Support Vector Machine (SVM) is used as a classifier to carry out the verification between imposters and customers. The proposed method has been tested on CASIA-3D face database and the experimental results show that our method achieves a high verification performance.

우리나라 중소하천 코리도의 자연성 평가기법 연구 (A Study on Evaluation Method of Stream Naturalness for Ecological Restoration of Stream Corridors)

  • 조용현
    • 한국조경학회지
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    • 제25권2호
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    • pp.73-81
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    • 1997
  • The main purpose of this study was to develop a new method for evaluation of stream naturalness in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. The results are as follows : 1) For this purpose six factors were selected on considering the spatial axes of stream corridor variation and total 20 descriptors about the physical structure were selected. 2) The calculation of S.N.I. for each segment was consisted of three steps, such as calculation of S.N.I.s of the individual descriptors, averaging all the descriptors's for each factor, and finally averaging the factors's for the Total S.N.I. 3) The evaluation unit was decided to be 100m size. The score system ranging 1~5 was adopted. Weighting parameters of factors were unified with each other. 4) A GIS model was adopted for classification, calculation, querying, analysing, and presenting S.N.I. information. And the format of S.N.I. maps including statistical graphs and other spatial watershed information was designed for the GIS odel. The naturalness of stream corridor was was investigated by the naturalness of habitat, and assessed by the descriptors focused on physical structure, therefore the S.N.I. can manifest prescriptions for restoration of the stream corridor. On the other hand because some evaluation factors such as water quality, water volume, fauna, flora, functions of stream exosystem has been excluded, S.N.I. could have some limits on representing the full aspects of stream naturalness. This evaluation method is hypothetical one, so it would be investigated through iterative applicatons.

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Person-Independent Facial Expression Recognition with Histograms of Prominent Edge Directions

  • Makhmudkhujaev, Farkhod;Iqbal, Md Tauhid Bin;Arefin, Md Rifat;Ryu, Byungyong;Chae, Oksam
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권12호
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    • pp.6000-6017
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    • 2018
  • This paper presents a new descriptor, named Histograms of Prominent Edge Directions (HPED), for the recognition of facial expressions in a person-independent environment. In this paper, we raise the issue of sampling error in generating the code-histogram from spatial regions of the face image, as observed in the existing descriptors. HPED describes facial appearance changes based on the statistical distribution of the top two prominent edge directions (i.e., primary and secondary direction) captured over small spatial regions of the face. Compared to existing descriptors, HPED uses a smaller number of code-bins to describe the spatial regions, which helps avoid sampling error despite having fewer samples while preserving the valuable spatial information. In contrast to the existing Histogram of Oriented Gradients (HOG) that uses the histogram of the primary edge direction (i.e., gradient orientation) only, we additionally consider the histogram of the secondary edge direction, which provides more meaningful shape information related to the local texture. Experiments on popular facial expression datasets demonstrate the superior performance of the proposed HPED against existing descriptors in a person-independent environment.

Quantitative Structure Activity Relationship Prediction of Oral Bioavailabilities Using Support Vector Machine

  • Fatemi, Mohammad Hossein;Fadaei, Fatemeh
    • 대한화학회지
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    • 제58권6호
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    • pp.543-552
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    • 2014
  • A quantitative structure activity relationship (QSAR) study is performed for modeling and prediction of oral bioavailabilities of 216 diverse set of drugs. After calculation and screening of molecular descriptors, linear and nonlinear models were developed by using multiple linear regression (MLR), artificial neural network (ANN), support vector machine (SVM) and random forest (RF) techniques. Comparison between statistical parameters of these models indicates the suitability of SVM over other models. The root mean square errors of SVM model were 5.933 and 4.934 for training and test sets, respectively. Robustness and reliability of the developed SVM model was evaluated by performing of leave many out cross validation test, which produces the statistic of $Q^2_{SVM}=0.603$ and SPRESS = 7.902. Moreover, the chemical applicability domains of model were determined via leverage approach. The results of this study revealed the applicability of QSAR approach by using SVM in prediction of oral bioavailability of drugs.

통계적 얼굴 모델을 이용한 부분적으로 가려진 얼굴 검출 (Detection of Faces with Partial Occlusions using Statistical Face Model)

  • 서정인;박혜영
    • 정보과학회 논문지
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    • 제41권11호
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    • pp.921-926
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    • 2014
  • 얼굴 검출은 입력 영상에서 얼굴 영역을 추출하는 과정으로, 얼굴 인식 및 인증 과정의 속도와 정확도를 효율적으로 높여주는 작업이며 그 응용분야도 다양하다. 기존에 개발된 얼굴 검출 방법들은 얼굴의 전체 형태를 바탕으로 검출을 수행하기 때문에 착용물 또는 신체 부위로 인해 일부가 가려져 폐색된 얼굴에 대해서는 그 검출 성능이 크게 하락할 수 있다. 이러한 문제를 해결하기 위하여 이 논문에서는 얼굴 영상을 지역적 특징 기술자의 집합으로 표현하고, 이에 대한 통계적 확률 모델을 추정한 뒤 이를 이용하여 입력 영상에서 얼굴 영역을 추출하는 방법을 제안한다. AR 데이터베이스와 Caltech 데이터베이스를 이용한 실험을 통해 제안하는 얼굴 검출 방법이 일부가 폐색된 얼굴 검출에 효과적임을 확인하였다.

Tracking of Moving Objects Using Morphological Segmentation, Statistical Moments and Hough Transform

  • Ahmad, Muhammad Bilal;Chang, Min-Hyuk;Park, Jong-An
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1377-1381
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    • 2003
  • This paper describes real time object tracking of 3D objects in 2D image sequences. The moving objects are segmented from the image sequence using morphological operations. The moving objects are segmented by the method of differential image followed by the process of morphological dilation. The moving objects are recognized and tracked using statistical moments. The direction of moving objects are determined by the Hough transform. The straight lines in the moving objects are found with the help of Hough transform. The direction of the moving object is calculated from the orientation of the straight lines in the direction of the principal axes of the moving objects. The direction of the moving object and the displacement of the object in the image sequence is used to calculate the velocity of the moving objects. The simulation results of the proposed method are promising on the test images.

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실시간 다중 객체 인식 및 추적 기법 (Real-time Multi-Objects Recognition and Tracking Scheme)

  • 김대훈;노승민;황인준
    • 한국항행학회논문지
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    • 제16권2호
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    • pp.386-393
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    • 2012
  • 본 논문에서는 객체의 관심점(interest points)에 대한 지역 특징 기술자를 이용하여 이미지나 동영상에서 다수의 관심 객체를 효과적으로 인식하고 추적하기 위한 기법을 제안한다. 이를 위해 먼저 대상이 되는 객체를 포함하는 다양한 이미지를 수집하고 SURF 알고리즘을 적용하여 객체의 관심점과 그들에 대한 지역 특징 기술자를 생성한다. 지역 특징에 대한 통계적인 분석을 통하여 관심점들 중에서 해당 객체의 특성을 가장 잘 표현하는 대표점(representative points)을 선택하고 이를 바탕으로 이미지에 존재하는 객체를 인식한다. 또한, 지역 특징 기술자의 정합을 응용하여 각 SURF 지점들의 움직임 벡터를 생성하고 이를 기반으로 실시간으로 객체를 추적한다. 제안하는 기법은 모든 객체를 독립적으로 다루기 때문에, 여러 개의 객체를 동시에 인식하고 추적할 수 있다. 다양한 실험을 통해, 동영상에서 객체의 존재 여부 및 종류를 신속하게 판별하고 관심 객체의 추적을 효과적으로 수행할 수 있음을 보인다.