• Title/Summary/Keyword: Projection method

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A Method for Identification of Harmful Video Images Using a 2-Dimensional Projection Map

  • Kim, Chang-Geun;Kim, Soung-Gyun;Kim, Hyun-Ju
    • Journal of information and communication convergence engineering
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    • v.11 no.1
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    • pp.62-68
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    • 2013
  • This paper proposes a method for identification of harmful video images based on the degree of harmfulness in the video content. To extract harmful candidate frames from the video effectively, we used a video color extraction method applying a projection map. The procedure for identifying the harmful video has five steps, first, extract the I-frames from the video and map them onto projection map. Next, calculate the similarity and select the potentially harmful, then identify the harmful images by comparing the similarity measurement value. The method estimates similarity between the extracted frames and normative images using the critical value of the projection map. Based on our experimental test, we propose how the harmful candidate frames are extracted and compared with normative images. The various experimental data proved that the image identification method based on the 2-dimensional projection map is superior to using the color histogram technique in harmful image detection performance.

Accuracy Improvement of Output in Projection Stereolithography by Optimizing Projection Resolution (전사방식 광조형 시스템의 해상도 최적화를 통한 출력물의 정밀도 향상)

  • Kim, Yeong-Heum;Kim, Kyu-Eon;Lee, Chibum
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.6
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    • pp.710-717
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    • 2015
  • Projection stereolithography is an additive manufacturing method that uses beam projection to cure the photo-reactive resin used. The light source of a cross-section layer-form illuminates photo-curable resin for building a three-dimensional (3D) model. This method has high accuracy and a fast molding speed because the processing unit is a face instead of a dot. This study describes a Scalable Projection Stereolithography 3D Printing System for improving the accuracy of the stereolithography. In a conventional projection 3D printer, when printing a small sized model, many pixels are not used in the projection or curing. The proposed system solves this problem through an optical adjustment, and keeps using the original image as possible as filling the whole projection area. The experimental verification shows that the proposed system can maintain the highest level of precision regardless of the output size.

Fast Computation of Projection Image Based on the Repeated Patterns of Intersection between Ray and Voxel (Ray와 Voxel 교차 길이 반복성 기반 고속 Projection 영상 생성 기법)

  • Lee, Hyunjeong;Kim, Jeongtae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.6
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    • pp.942-948
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    • 2017
  • Ray-tracing based method for computing projection image calculates the exact amounts of the intersection between voxels and a ray. Among several different implementations of the ray tracing based methods, Siddon's method is the earliest one. Later faster implementation such as Jacobs's method, Zhao's method, were investigated. To our knowledge, Zhao's method is the fastest one among these. We improve the speed of the Zhao's method by predicting the number of the same intersection length between voxel and a ray. In our experiment, the proposed method showed significantly faster computation speed than Zhao's method.

Pose Identification Using Isometric Projection

  • Islam, Ihtesham-Ul;Kim, In-Taek
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.979-980
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    • 2008
  • In this paper we use the Isometric Projection, a linear subspace method, for manifold representation of the pose-varying-faces. Isometric Projection method for pose identification is evaluated on view varying faces and is compared with other global and local linear subspace methods.

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A SIMPLE METHOD FOR OBTAINING PROJECTION MATRIX USING ALGEBRAIC PROPERTIES

  • Hasik, Sun-Woo
    • Journal of applied mathematics & informatics
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    • v.8 no.2
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    • pp.651-658
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    • 2001
  • The projection matrix plays an important role in the linear model theory. In this paper we derive an algebraic relationship between the projection matrices of submatrices of the design matrix. Using this relationship we can easily obtain the projection matrices of any submatrices of the design matrix. Also we show that every projection matrix can be obtained as a linear combination of Kronecker products of identity matrices and matrices with all elements equal to 1.

Pupil Detection using Hybrid Projection Function and Rank Order Filter (Hybrid Projection 함수와 Rank Order 필터를 이용한 눈동자 검출)

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.27-34
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    • 2014
  • In this paper, we propose a pupil detection method using hybrid projection function and rank order filter. To reduce error to detect eyebrows as pupil, eyebrows are detected using hybrid projection function in face region and eye region is set to not include the eyebrows. In the eye region, potential pupil candidates are detected using rank order filter and then the positions of pupil candidates are corrected. The pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using template matching, we select a pair with the smallest similarity measure as final two pupils. The experiments have been performed for 700 images of the BioID face database. The pupil detection rate is 92.4% and the proposed method improves about 21.5% over the existing method..

On Linear Discriminant Procedures Based On Projection Pursuit Method

  • Hwang, Chang-Ha;Kim, Dae-Hak
    • Journal of the Korean Data and Information Science Society
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    • v.5 no.1
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    • pp.1-10
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    • 1994
  • Projection pursuit(PP) is a computer-intensive method which seeks out interesting linear projections of multivariate data onto a lower dimension space by machine. By working with lower dimensional projections, projection pursuit avoids the sparseness of high dimensional data. We show through simulation that two projection pursuit discriminant mothods proposed by Chen(1989) and Huber(1985) do not improve very much the error rate than the existing methods and compare several classification procedures.

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ON STUDY OF f-APPROXIMATION PROBLEMS AND σ-INVOLUTORY VARIATIONAL INEQUALITY PROBLEMS

  • Mitra, Siddharth;Das, Prasanta Kumar
    • Nonlinear Functional Analysis and Applications
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    • v.27 no.2
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    • pp.223-232
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    • 2022
  • The purpose of the paper is to define f-projection operator to develop the f-projection method. The existence of a variational inequality problem is studied using fixed point theorem which establishes the existence of f-projection method. The concept of ρ-projective operator and σ-involutory operator are defined with suitable examples. The relation in between ρ-projective operator and σ-involutory operator are shown. The concept of σ-involutory variational inequality problem is defined and its existence theorem is also established.

3-D Profile Measurement System of Live Human Faces for the '93 Taejon Expo Kumdori Robot Scupltor (93 대전엑스포 꿈돌이 조각가로보트의 인물형상 측정시스템)

  • 김승우;박현구;김문상
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.3
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    • pp.670-679
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    • 1995
  • This paper presents the 3-D profile measurement system of live human faces, which was developed specially for 'KUMDORI sculptor robot' of the '93 Taejon Exposition. '93 Taejon EXPO. The basic principle for measurement adopts the slit beam projection which is a method of measuring 3-D surface profiles using geometric optics between the slit beam and the CCD camera. Since the slit beam projection consumes long measuring time, it is unfit to measure the 3-D profiles of living objects as human. Therefore, the projection type slit beam method which consumes short measuring time is newly suggested. And an algorithm to reconstruct the 3-D profile from the deformed images using finite approximated calibration is suggested and practically implemented. The projection type slit beam method was applied to spectators in a period of '93 Taejon EXPO. The measurement results show that the technique is suitable for 3-D face profile measurement on a living body.

Economic Dispatch of Thermal Units of a GENCO Using the Gradient Projection Method (경사 투영법을 이용한 발전사업자의 경제급전)

  • 정정원
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.9
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    • pp.550-556
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    • 2003
  • Price-based unit commitment is one of bidding strategies which a Genco may take in a practical manner. For that purpose, it is required for a Genco to decide output levels of its generators at each trade period. In this paper, an economic dispatch of thermal units is proposed considering the quantity of reserve contracts. A gradient projection algorithm is adopted as an optimization tool. A direct form of a projection matrix without any calculation of matrix inverse and multiplications is induced. Besides, it is proved that there is no need to check one of the two optimality conditions in the gradient projection method, which also requires matrix inverse and multiplications.