• 제목/요약/키워드: Gradient feature

검색결과 279건 처리시간 0.031초

가중치 세분화 기반의 로지스틱 회귀분석 모델 (Fine-Grain Weighted Logistic Regression Model)

  • 이창환
    • 전자공학회논문지
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    • 제53권9호
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    • pp.77-81
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    • 2016
  • 로지스틱 회귀분석은 오랫동안 다양한 분야에서 예측을 위한 기술 혹은 변수 간의 관계를 설명하기 위하여 사용되어 왔다. 로지스틱 회귀분석에서 각 속성은 목적 값에 대한 중요도를 가지는데 본 연구에서는 이를 세분화하여 각 속성의 값에 따라서 중요도를 부여하는 새로운 방법을 제시한다. 점진적 하강법을 이용하여 알고리즘의 성능을 최대화하는 각 속성값 가중치의 값을 계산하였다. 제안된 방법은 다양한 데이터를 이용하여 실험하였고 본 연구의 속성값 기반 로지스틱 회귀분석 방법은 기존의 로지스틱 회귀분석보다 우수한 학습 능력을 보임을 알 수 있었다.

Smoke Detection System Research using Fully Connected Method based on Adaboost

  • Lee, Yeunghak;Kim, Taesun;Shim, Jaechang
    • Journal of Multimedia Information System
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    • 제4권2호
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    • pp.79-82
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    • 2017
  • Smoke and fire have different shapes and colours. This article suggests a fully connected system which is used two features using Adaboost algorithm for constructing a strong classifier as linear combination. We calculate the local histogram feature by gradient and bin, local binary pattern value, and projection vectors for each cell. According to the histogram magnitude, this paper applied adapted weighting value to improve the recognition rate. To preserve the local region and shape feature which has edge intensity, this paper processed the normalization sequence. For the extracted features, this paper Adaboost algorithm which makes strong classification to classify the objects. Our smoke detection system based on the proposed approach leads to higher detection accuracy than other system.

Object Cataloging Using Heterogeneous Local Features for Image Retrieval

  • Islam, Mohammad Khairul;Jahan, Farah;Baek, Joong Hwan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권11호
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    • pp.4534-4555
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    • 2015
  • We propose a robust object cataloging method using multiple locally distinct heterogeneous features for aiding image retrieval. Due to challenges such as variations in object size, orientation, illumination etc. object recognition is extraordinarily challenging problem. In these circumstances, we adapt local interest point detection method which locates prototypical local components in object imageries. In each local component, we exploit heterogeneous features such as gradient-weighted orientation histogram, sum of wavelet responses, histograms using different color spaces etc. and combine these features together to describe each component divergently. A global signature is formed by adapting the concept of bag of feature model which counts frequencies of its local components with respect to words in a dictionary. The proposed method demonstrates its excellence in classifying objects in various complex backgrounds. Our proposed local feature shows classification accuracy of 98% while SURF,SIFT, BRISK and FREAK get 81%, 88%, 84% and 87% respectively.

Lipophilic Acyclic Polyether Dicarboxylic Acid 에 의한 액체막을 통한 금속이온의 이동 (Transport of Metal Ions Across Bulk Liquid Membrane by Lipophilic Acyclic Polyether Dicarboxylic Acids)

  • 조문환;조성호;이인종
    • 대한화학회지
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    • 제38권2호
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    • pp.129-135
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    • 1994
  • Acyclic polyether dicarboxylic acid는 액체막계에서 금속이온의 운반체로 연구되었다. 수소이온이 이온화될 수 있는 리간드는 금속이온의 이동에 수소이온이 반대방향으로 이동된다. 이와 같은 리간드는 pH를 변화시키면 효과적으로 금속이온을 분리할 수 있고 농축시킬 수도 있다. 금속이온의 이동은 source phase의 염기의 농도와 receiving phase의 산의 농도를 증가시키면 증가된다. Acyclic polyether dicarboxylic acids를 운반체로 사용한 경쟁이동반응에서 칼슘이온을 선택적으로 분리할 가능성이 있다.

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러프 집합 이론을 이용한 3차원 물체 특징 추출 (3D Feature Detection using Rough Set Theory)

  • 정영준;전효병;심귀보
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 G
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    • pp.2222-2224
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    • 1998
  • This paper presents a 3D feature extraction method using rough set theory. Using the stereo cameras, we obtain the raw images and then perform several processes including gradient computation and image matching process. Decision rule constructed via rough set theory determines whether a ceratin point in the image is 3D edge or not. We propose a method finding rules for 3D edge extraction using rough set.

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Support Vector Machine을 이용한 유해 이미지 분류 (Adult Image Filtering using Support Vector Mchine)

  • 송철환;유성준
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (C)
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    • pp.218-221
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    • 2006
  • 본 논문은 인터넷의 대표적인 문제점중의 하나인 Adult Image 분류 연구에 대해 기술한다. 특히 우리는 이러한 Adult Image를 분류하기 위한 Data Set을 5가지 타입으로 구성한다. 이러한 각 Image에 대해 Color, Gradient, Edge Direction 특성의 Feature들을 추출하고 이를 Histogram으로 구성한다. 이렇게 구성된 Histogram을 Support Vector Machine에 적용하여 Adult Image를 분류한다. 그 결과, 우리는 8250개의 Test Set에 대하여 Recall(96.53%), Precision(97.33%), False Positive(2.96%), F-Measure(96.93%)의 성능 결과를 보여준다.

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생체 인식을 위한 홍채 영상에서의 3차원 특징 추출 (Three dimensional feature extraction of iris images for biometrics)

  • 김석민;김재한
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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    • pp.309-312
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    • 2003
  • 기존 홍채 인식 시스템의 접안식 영상 획득상 불편한 사항을 해결하고 인식의 정확도를 높이기 위해서는 원격으로 영상을 획득할 수 있어야 하며, 홍채의 경계선을 정확하게 검출할 수 있어야 한다. 또한 기존 홍채 영역 검출 방법의 문제점인 홍채를 원으로 가정하는 방식을 개선할 필요성이 있다. 따라서 본 논문에서는 조명에 의한 glint 정보와 intensity gradient를 이용하여 홍채의 경계를 산출하였으며, 아울러 스테레오스코픽 카메라를 이용하여 홍채 경계의 3차원 좌표를 획득함으로써, 카메라를 기준으로 하는 홍채의 주시각을 찾아 홍채의 원형 변환에 활용하도록 하였다.

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Comparative Study of GDPA and Hough Transformation for Automatic Linear Feature Extraction

  • Ryu, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.238-240
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    • 2003
  • As remote sensing is weighty in GIS updating, it is indispensable to get spatial information quickly and exactly. In this study, we have designed and implemented the program by two algorithms of GDPA (Gradient Direction Profile Analysis) and Hough transformation to extract linear features automatically from high-resolution imagery. We applied the software to embody both algorithms to KOMPSAT-EOC, IKONOS, and Landsat-ETM and made a comparative study of results.

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Lane Detection Algorithm for Night-time Digital Image Based on Distribution Feature of Boundary Pixels

  • You, Feng;Zhang, Ronghui;Zhong, Lingshu;Wang, Haiwei;Xu, Jianmin
    • Journal of the Optical Society of Korea
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    • 제17권2호
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    • pp.188-199
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    • 2013
  • This paper presents a novel algorithm for nighttime detection of the lane markers painted on a road at night. First of all, the proposed algorithm uses neighborhood average filtering, 8-directional Sobel operator and thresholding segmentation based on OTSU's to handle raw lane images taken from a digital CCD camera. Secondly, combining intensity map and gradient map, we analyze the distribution features of pixels on boundaries of lanes in the nighttime and construct 4 feature sets for these points, which are helpful to supply with sufficient data related to lane boundaries to detect lane markers much more robustly. Then, the searching method in multiple directions- horizontal, vertical and diagonal directions, is conducted to eliminate the noise points on lane boundaries. Adapted Hough transformation is utilized to obtain the feature parameters related to the lane edge. The proposed algorithm can not only significantly improve detection performance for the lane marker, but it requires less computational power. Finally, the algorithm is proved to be reliable and robust in lane detection in a nighttime scenario.

CAD Scheme To Detect Brain Tumour In MR Images using Active Contour Models and Tree Classifiers

  • Helen, R.;Kamaraj, N.
    • Journal of Electrical Engineering and Technology
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    • 제10권2호
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    • pp.670-675
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    • 2015
  • Medical imaging is one of the most powerful tools for gaining information about internal organs and tissues. It is a challenging task to develop sophisticated image analysis methods in order to improve the accuracy of diagnosis. The objective of this paper is to develop a Computer Aided Diagnostics (CAD) scheme for Brain Tumour detection from Magnetic Resonance Image (MRI) using active contour models and to investigate with several approaches for improving CAD performances. The problem in clinical medicine is the automatic detection of brain Tumours with maximum accuracy and in less time. This work involves the following steps: i) Segmentation performed by Fuzzy Clustering with Level Set Method (FCMLSM) and performance is compared with snake models based on Balloon force and Gradient Vector Force (GVF), Distance Regularized Level Set Method (DRLSE). ii) Feature extraction done by Shape and Texture based features. iii) Brain Tumour detection performed by various tree classifiers. Based on investigation FCMLSM is well suited segmentation method and Random Forest is the most optimum classifier for this problem. This method gives accuracy of 97% and with minimum classification error. The time taken to detect Tumour is approximately 2 mins for an examination (30 slices).