• Title/Summary/Keyword: shape error

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An Error Examination of 3D Face Automatic Recognition (3차원 안면자동인식기의 형상복원 오차검사)

  • Suk, Jae-Hwa;Cho, Kyung-Rae;Cho, Yong-Beum;Yoo, Jung-Hee;Kwak, Chang-Kyu;Lee, Soo-Kyung;Kho, Byung-Hee;Kim, Jong-Won;Kim, Kyu-Kon;Lee, Eui-Ju
    • Journal of Sasang Constitutional Medicine
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    • v.18 no.2
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    • pp.41-49
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    • 2006
  • 1. Objectives The Face is an important standard for the classification of Sasang Contitutions. We are developing 3D Face Automatic Recognition Apparatus to analyse the facial characteristics. So We should examine a shape demobilization error of 3D Face Automatic Recognition Apparatus. 2. Methods We compared facial shape data be demobilized by 3D Face Automatic Recognition Apparatus with facial shape data that be demobilized by 3D laser scanner. The subject was two korean men. And We analysed the average error and the maximum error of two data. In this process, We used one datum point(the peak of nose) and two datum line(vertical section and horizontal section). 3. Results and Conclusions In each this comparison, the average error of vertical section was 1.962574mm and 2.703814mm. and the maximum error of vertical section was 16.968249mm and 18.61464mm. the average error of horizontal section was 4.173203mm and 21.487479mm. and the maximum error of horizontal section was 3.571210mm and 17.13255mm. Also We complemented this apparatus a little and We reexamined a shape demobilization error of 3D Face Automatic Recognition Apparatus again. Accuracy of a shape demobilization was improved a little. From now on We complement accuracy of a shape demobilization in 3D Face Recognition Apparatus.

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Optimization of Motion Control System on the Machine Tool (공작기계의 이송계 제어 시스템의 최적화)

  • 박인준;곽경남;백형래
    • Proceedings of the KIPE Conference
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    • 1997.07a
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    • pp.336-340
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    • 1997
  • This paper is a study about motor technic of motion and feedforward control in order to shape cutting control on the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control, shape error generated by the position command delay is minimized by using the acceleration/deceleration time constant after the interpolation. The study was verified to optimization of motion control on experiments of a vertical machining center of the machine tool.

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A Pollution Adaptive Mesh Generation Algorithm Using Singular Shape Functions (특이 형상함수를 이용한 Pollution 적응 요소생성 알고리즘)

  • 유형선;장준환;편수범
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.110-118
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    • 2001
  • In many areas of finite element analysis, elements with special properties are required to achieve maximal accuracy. As examples, we may mention infinite elements for the representation of spatial domain that extend to special and singular elements for modeling point and line singularities engendered by geomeric features such as reentrant corners and cracks. In this paper, we study on modified shape function representing singular properties and algorigthm for the pollution adaptive mesh generation. We will also show that the modified shape function reduces pollution error and local error.

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Form Error Prediction in Side Wall Milling Considering Tool Deflection (측벽 엔드밀 가공에서 공구 변형을 고려한 형상 오차 예측)

  • 류시형;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.6
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    • pp.43-51
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    • 2004
  • A method for form error prediction in side wall machining with a flat end mill is suggested. Form error is predicted directly from the tool deflection without surface generation by cutting edge locus with time simulation. Developed model can predict the surface form error about three hundred times faster than the previous method. Cutting forces and tool deflection are calculated considering tool geometry, tool setting error and machine tool stiffness. The characteristics and the difference of generated surface shape in up milling and down milling are discussed. The usefulness of the presented method is verified from a set of experiments under various cutting conditions generally used in die and mold manufacturing. This study contributes to real time surface shape estimation and cutting process planning for the improvement of form accuracy.

System Developement for STL Error Correction and Shape Modification (STL의 오류수정 및 형상수정 시스템의 개발)

  • Chae, Hee-Chang
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.3 s.96
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    • pp.53-61
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    • 1999
  • STL has several errors such as orientation error, hole error, and acute triangle error on being translated from CAD software. These errors should be corrected before using in Rapid Prototyping. So the software is necessary to correct errors. In this study, STL Editor which is a system for STL error correction and shape modification is developed and contains following characteristics. 1.Apply the triangle based data st겨cture. 2.Use the graphic user interface for easy work. 3.Use the Diet method to reduce data size. 4.Use the Delaunay triangulation method to enhance the quality of STL. 5.Modify the STL errors manually.

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Shape Monitoring of Composite Cantilever Beam by Using Fiber Bragg Grating Sensors (광섬유 브래그 격자 센서를 이용한 복합재 외팔보의 형상 모니터링)

  • Lee, Kun-Ho;Kim, Dae-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.7
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    • pp.833-839
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    • 2013
  • In this study, an experiment was performed to monitor the two-dimensional shape of a cantilever composite structure using fiber Bragg grating (FBG) sensors. To monitor the shape of a composite structure, a deflection equation developed by NASA was applied and a composite beam attached to three FBG sensors was used. In the experiment, the shape of the composite beam was successfully estimated and an error was evaluated by comparing a real deflection. The error increased with real deflection; therefore, it was compensated by using the linear relationship between the error and the real deflection. After compensating the error, the measured deflection shows good agreement with the real deflection. Finally, the experiment shows that the FBG sensor and the deflection equation are suitable for monitoring the deflection curve of the beam structure with compensation of the error.

A Study on the Characteristics of Software Reliability Model Using Exponential-Exponential Life Distribution (수명분포가 지수화-지수분포를 따르는 소프트웨어 신뢰모형 특성에 관한 연구)

  • Kim, Hee Cheul;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.27 no.3
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    • pp.69-75
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    • 2020
  • In this paper, we applied the shape parameters of the exponentialized exponential life distribution widely used in the field of software reliability, and compared the reliability properties of the software using the non-homogeneous Poisson process in finite failure. In addition, the average value function is also a non-decreasing form. In the case of the larger the shape parameter, the smaller the estimated error in predicting the predicted value in comparison with the true value, so it can be regarded as an efficient model in terms of relative accuracy. Also, in the larger the shape parameter, the larger the estimated value of the coefficient of determination, which can be regarded as an efficient model in terms of suitability. So. the larger the shape parameter model can be regarded as an efficient model in terms of goodness-of-fit. In the form of the reliability function, it gradually appears as a non-increasing pattern and the higher the shape parameter, the lower it is as the mission time elapses. Through this study, software operators can use the pattern of mean square error, mean value, and hazard function as a basic guideline for exploring software failures.

Study on Estimating the Shape of a Ship by Integrating Radar Images

  • Ishiwata, Junya;Fujisaka, Takahiko;Imazu, Hayama
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.10a
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    • pp.71-78
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    • 2006
  • The image of an object obtained by the radar is not corresponding to its true shape, because the image of an object observed by the radar is receiving an influence such as multiple-reflections and expanded in bearing because of the beam width of a radar. In addition, a radio wave does not hit the entire surface of an object. Therefore, the image of the front side of a ship facing a radar antenna corresponds to its true shape. In this paper, a method to estimate a ship's shape by means of the integration of the front parts of images obtained from radars is proposed. In addition, a matter, which is observation error of each radar, in using multi-radars, and the process included in the proposed method for solving the matter, are described. As a result of the experiment, the accuracy of about 3 degrees in ship's heading and about 14 meters in length and about 9 meters in beam was obtained.

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Recursive Error-Component Correcting Method for 3D Shape Reconstruction (3차원 형상 복원을 위한 재귀적 오차 성분 보정 방법)

  • Koh, Sung-shik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.10
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    • pp.1923-1928
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    • 2017
  • This paper is a study on error correction for three-dimensional shape reconstruction based on factorization method. The existing error correction method based on factorization has a limitation of correction because it is optimized globally. Thus in this paper, we propose our new method which can find and correct the only major error influence factor toward three-dimensional reconstructed shape instead of global approach. We define the error-influenced factor in two-dimensional re-projection deviation space and directly control the error components. In addition, it is possible to improve the error correcting performance by recursively applying the above process. This approach has an advantage under noise because it controls the major error components without depending on any geometric information. The performance evaluation of the proposed algorithm is verified by simulation with synthetic and real image sequence to demonstrate noise robustness.

A Study of Seam Tracking and Error Compensation for Plasma Arc Welding of Corrugation Panel

  • Yang, Joo-Woong;Park, Young-Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2701-2706
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    • 2003
  • This paper describes weld seam tracking and error compensation methods of automatic plasma arc welding system designed for the corrugation panel that consists of a linear section and a curved section with various curvatures. Realizing automatic welding system, we are faced with two problems. One is a precise seam tracking and the other is an arc length control. Due to the complexity of the panel shape, it is difficult to find a seam and operate a torch manually in the welding process. So, laser vision sensor for seam tracking is equipped for sensing the seam position and controlling the height of a torch automatically. To attain more precise measurement of an arc length, we measure the 3D shape of the panel and analyze error factors according to the various panel states and caused errors are predicted through the welding process. Using that result, compensation algorithm is added to that of arc length control and real time error compensation is achieved. The result shows that these two methods work effectively.

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