• Title/Summary/Keyword: Rotation-based method

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Seismic Design of Mid-to-Low Rise Steel Moment Frames Based on Available Connection Rotation Capacity (접합부 회전능력에 기초한 중/저층 철골모멘트골조의 내진설계)

  • Ahn, Jae Kwon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.19 no.6
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    • pp.715-723
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    • 2007
  • A displacement-based seismic design procedure was proposed for mid-to-low-rise steel moment frames. The proposed method was totally different from the current R-factor approach in that it directly uses available connection rotation capacity as a primary design variable. To this end, the relationship between available connection rotation capacity and seismic response modification (R factor) was established first; this relationship has been a missing link in current ductility-based design practice. A step-by-step displacement-based iterative design procedure was then proposed and verified using inelastic dynamic analysis.

Texture Classification Using Rotation Invariant Local Directional Pattern (Rotation Invariant Local Directional Pattern을 이용한 텍스처 분류 방법)

  • Lee, Tae Hwan;Chae, Ok Sam
    • Convergence Security Journal
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    • v.17 no.3
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    • pp.21-29
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    • 2017
  • Accurate encoding of local patterns is a very important factor in texture classification. However, LBP based methods w idely studied have fundamental problems that are vulnerable to noise. Recently, LDP method using edge response and dire ction information was proposed in facial expression recognition. LDP is more robust to noise than LBP and can accommod ate more information in it's pattern code, but it has drawbacks that it is sensitive to rotation transforms that are critical to texture classification. In this paper, we propose a new local pattern coding method called Rotation Invariant Local Direc tional Pattern, which combines rotation-invariant transform to LDP. To prove the texture classification performance of the proposed method in this paper, texture classification was performed on the widely used UIUC and CUReT datasets. As a result, the proposed RILDP method showed better performance than the existing methods.

Perforator-Based Fasciocutaneous Island Rotation Flap in Treatment of Pressure sore (천공분지에 기저를 둔 도서형 회전 근막 피부 피판을 이용한 압박궤양의 치료)

  • Kim, Ji-Su;Kim, Dong-Hoon;Lee, Dong-Lark;Lim, Jun-Kyu
    • Archives of Reconstructive Microsurgery
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    • v.16 no.1
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    • pp.23-29
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    • 2007
  • The reconstruction of deep soft tissue defect such as pressure sore has difficult problems. Myocutaneous flaps have been used commonly as the best coverage method for pressure sore. But, they have several drawbacks such as sacrifice of functional muscle, high morbidity of the donor sites and bulkiness at the recipient site. The concepts of perforator flap has recently developed and widely used to overcome these disadvantages. Between March 2005 to July 2006, we have treated 9 patients who had pressure sore using perforator based fasciocutaneous island rotation flap. Preoperative unidirectional Doppler was used in all cases. Mean number of perforator vessels was 3.8 and flap sizes were from $7{\times}5\;cm$ to $14{\times}13\;cm$. Rotation angles of flap were from 90 degree to 180 degree. In all cases, donor sites were closed primarily. All flap survived completely and postoperative complications were wound dehiscence in 1 case, wound infection in 3 cases. The mean postoperative follow up period was 15.7 months and recurrence was not reported. We could decrease donor site morbidity and cover wound sites easily by using flap rotation and get robust blood supply without sacrifice of functional muscle. Fasciocutaneous perforator island rotation flap would be very useful for various pressure sore treatment.

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New Template Based Face Recognition Using Log-polar Mapping and Affine Transformation (로그폴라 사상과 어파인 변환을 이용한 새로운 템플릿 기반 얼굴 인식)

  • Kim, Mun-Gab;Choi, Il;Chien, Sung-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.2
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    • pp.1-10
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    • 2002
  • This paper presents the new template based human face recognition methods to improve the recognition performance against scale and in-plane rotation variations of face images. To enhance the recognition performance, the templates are generated by linear or nonlinear operation on multiple images including different scales and rotations of faces. As the invariant features to allow for scale and rotation variations of face images, we adopt the affine transformation, the log-polar mapping, and the log-polar image based FFT. The proposed recognition methods are evaluated in terms of the recognition rate and the processing time. Experimental results show that the proposed template based methods lead to higher recognition rate than the single image based one. The affine transformation based face recognition method shows marginally higher recognition rate than those of the log-polar mapping based method and the log-polar image based FFT, while, in the aspect of processing time, the log-polar mapping based method is the fastest one.

Prediction of Cross Flow Fan Flow Using an Unstructured Finite Volume Method (비정렬 유한 체적법을 이용한 횡류홴 유동장 해석)

  • Kang, Dong-Jin;Bae, Sang-Su
    • The KSFM Journal of Fluid Machinery
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    • v.8 no.3 s.30
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    • pp.7-15
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    • 2005
  • A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate aye carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

A Study on CRM(Center of Rotation Method) based on MST(Minimum Spanning Tree) Matching Algorithm for Fingerprint Recognition

  • Kwon, Hyoung-Ki;Lee, Jun-Ho;Ryu, Young-Kee
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.55.5-55
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    • 2001
  • The MST (Minimum Spanning Tree) matching algorithm had been used for searching the part accord points extracted from the gray level fingerprint image. The method, however, had some limitations. To obtain the relationship between enrolled and inputted fingerprint, the MST was used to generate the tree graph that represent the unique graph for given fingerprint data. From the graph, the accord points are estimated. However, the shape of the graph highly depends on the positions of the minutiae. If there are some pseudo minutiae caused by noise, the shape of the graph will be different In this paper, to overcome the limitations of the MST, we proposed CRM (Center of Rotation Method) algorithm that found the true part accord points. The proposed method is based on the assumption ...

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Prediction of Cross Flow Fan Flow Using an Unstructured Finite Volume Method (비정렬 유한 체적법을 이용한 횡류 홴 유동장 해석)

  • Kang Dong-Jin;Bae Sang-Su
    • The KSFM Journal of Fluid Machinery
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    • v.9 no.4 s.37
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    • pp.27-35
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    • 2006
  • A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate are carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

Corner Inspection of Autoclave-cured L-shaped Composite Structure using Pulse-echo Rotation Scanning Scheme based on Laser Ultrasonic (레이저 초음파 기반 반사식 회전 검사 기법을 이용한 오토클레이브 가공 L 형 복합재 구조물의 모서리 검사)

  • Lee, Young-Jun;Lee, Jung-Ryul;Hong, Sung-Jin
    • Composites Research
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    • v.31 no.5
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    • pp.246-250
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    • 2018
  • In this paper, laser ultrasonic rotation scanning method was proposed to inspect and visualize defects in corner section of curved composite structure. L-shaped composite specimen with defects in its corner section were inspected using laser ultrasonic rotation scanning method. L-shaped specimens had artificial defects at three different depths to simulate delamination damage. All artificial defects were detected clearly in different time-of-flight according to their depths. Inspection result showed that the proposed method is suitable to inspect round corner section of curved composite structure without any special tools.

Reliability and Validity of Measurement Using Smartphone-Based Goniometer of Tibial External Rotation Angle in Standing Knee Flexion

  • Jeon, In-Cheol;Kwon, Oh-Yun;Weon, Jong-Hyuck;Ha, Sung-Min;Kim, Si-Hyun
    • Physical Therapy Korea
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    • v.20 no.2
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    • pp.60-68
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    • 2013
  • The purpose of this study was to assess the intra-rater test-retest reliability of tibial external rotation angle measurement using a smartphone-based photographic goniometer, DrGoniometer (DrG) compared to a three-dimensional motion analysis system (Vicon). The current study showed an interchangeable method using DrG to measure the tibial external rotation angle in standing knee flexion at $90^{\circ}$. Twelve healthy subjects participated in this study. A rest session was conducted 30 minutes later for within-day reliability and five days later for between-day intra-rater test-retest reliability. To assess the validity of the measurement using DrG, we used a three dimensional motion analysis system as a gold standard to measure the angle of tibial external rotation. Intra-class correlation coefficient (ICC) and the standard error of measurement (SEM) values were used to determine the within- and between- day intra-rater test-retest reliability of using DrG and a three dimensional motion analysis system. To assess validity, Pearson correlation coefficients were used for two measurement techniques. The measurement for tibial external rotation had high intra-rater test-retest reliability of within-day (ICC=.88) and between-day (ICC=.83) reliability using DrG and of within-day (ICC=.93) and between-day (ICC=.77) reliability using a three-dimentional motion analysis system. Tibial external rotation angle measurement using DrG was highly correlated with those of the three-dimensional motion analysis system (r=.86). These results represented that the tibial external rotation angle measurement using DrG showed acceptable reliability and validity compared with the use of three-dimensional motion analysis system.

Development of Color 3D Scanner Using Laser Structured-light Imaging Method

  • Ko, Youngjun;Yi, Sooyeong
    • Current Optics and Photonics
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    • v.2 no.6
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    • pp.554-562
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    • 2018
  • This study presents a color 3D scanner based on the laser structured-light imaging method that can simultaneously acquire 3D shape data and color of a target object using a single camera. The 3D data acquisition of the scanner is based on the structured-light imaging method, and the color data is obtained from a natural color image. Because both the laser image and the color image are acquired by the same camera, it is efficient to obtain the 3D data and the color data of a pixel by avoiding the complicated correspondence algorithm. In addition to the 3D data, the color data is helpful for enhancing the realism of an object model. The proposed scanner consists of two line lasers, a color camera, and a rotation table. The line lasers are deployed at either side of the camera to eliminate shadow areas of a target object. This study addresses the calibration methods for the parameters of the camera, the plane equations covered by the line lasers, and the center of the rotation table. Experimental results demonstrate the performance in terms of accurate color and 3D data acquisition in this study.