• Title/Summary/Keyword: Shape finding

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A Study on the Relationship between Flexural Beam Shape and Transport Characteristics for the Ultrasonic Transport Systems (초음파 이송 시스템에서 Flexural Beam의 형태 변화와 물체 이송과의 관계에 대한 연구)

  • 정상화;신병수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.25-29
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    • 2003
  • In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phase-difference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified and the system performance for practical use is evaluated.

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Transport Characteristics according to Flexural Beam Shape for the Ultrasonic Transport Systems (초음파 물체 이송시스템에서 Flexural Beam 의 형태 변화에 따른 이송특성에 관한 연구)

  • Shin, Byung-Su;Jeong, Sang-Hwa;Cha, Kyung-Rae
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1608-1613
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    • 2003
  • In the semiconductor and the optical industry, a new transport system which can replace the conventional sliding system is required. These systems are driven by the magnetic field and the conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problems. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phasedifference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified. In addition, the system performance for practical use is evaluated.

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A Study on Motion Characteristics of the Ultrasonic Transporting System according to the change of Flexural Beam Shape (Flexural Beam의 형태 변화에 따른 초음파 이송시스템의 동작특성에 관한 연구)

  • 정상화;신병수;차경래
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.696-699
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    • 2003
  • In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. There systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phase-difference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified and the system performance for practical use is evaluated.

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A Study of Shape Finding of Equally Stressed Surface for Membrane Structures by Dynamic Relaxation Method (동적이완법에 의한 막구조의 등장력곡면 형태해석에 관한 연구)

  • 한상을;이경수
    • Computational Structural Engineering
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    • v.11 no.4
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    • pp.321-330
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    • 1998
  • 막구조의 초기형상을 결정하기 위하여 막요소의 기하학적 비선형을 고려한 평형방정식을 유도하고, 등장력곡면(equally stressed surface)을 결정하기 위한 알고리즘을 정식화한다. 막구조는 대변형에 의한 기하학적 비선형성을 포함하고, 막구조의 특성상 초기장력에 의한 초기변형을 고려해야 하므로, 본 논문에서는 막구조와 같은 인장구조물의 비선형 수치해석을 수행하기 위한 해석기법으로써, 동적이완법(Dynamic Relaxation Method)에 대한 해석알고리즘을 적용하고, 이 방법에 의해 수행한 해석결과를 검토함으로써 막구조 해석에 적용 가능한 수치해석기법을 제시하고, 수치해석에 대한 예를 통해 본 해석법의 타당성을 검증한다.

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A Study on Hand Region Detection for Kinect-Based Hand Shape Recognition (Kinect 기반 손 모양 인식을 위한 손 영역 검출에 관한 연구)

  • Park, Hanhoon;Choi, Junyeong;Park, Jong-Il;Moon, Kwang-Seok
    • Journal of Broadcast Engineering
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    • v.18 no.3
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    • pp.393-400
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    • 2013
  • Hand shape recognition is a fundamental technique for implementing natural human-computer interaction. In this paper, we discuss a method for effectively detecting a hand region in Kinect-based hand shape recognition. Since Kinect is a camera that can capture color images and infrared images (or depth images) together, both images can be exploited for the process of detecting a hand region. That is, a hand region can be detected by finding pixels having skin colors or by finding pixels having a specific depth. Therefore, after analyzing the performance of each, we need a method of properly combining both to clearly extract the silhouette of hand region. This is because the hand shape recognition rate depends on the fineness of detected silhouette. Finally, through comparison of hand shape recognition rates resulted from different hand region detection methods in general environments, we propose a high-performance hand region detection method.

Active shape exploration of an unknown object by using robot hand (로봇손을 이용한 미지 물체의 능동적 형상탐사에 관한 연구)

  • 김진호;오상록;최혁렬
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.768-771
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    • 1997
  • Geometric probing addresses the problem of determining geometric aspects of a structure from the mathematics and results of a physical measuring device such as a probe. This paper presents a new algorithm to recognize the shape of an unknown object by using a robot hand with a force and torque sensor. The new algorithm is called S.E.P.(Shape Exploration Procedure) which finds the global shape of an unknown object. The proposed method is composed of three major parts, finding contact informations such as contact point, calculation of shape information such as curvature, and expression of global shape from these informations. Comparing with the conventional approaches, the advantages of the proposed method are explained and verified by conducting experiments with a 3-dof SCARA robot.

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A Study on the Shape Analysis of the Truss Structures under the Prescribed Displacement Mode (변위제약모드를 갖는 트러스구조물의 형태해석에 관한 연구)

  • 문창훈;김진기;최옥훈;한상을
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.262-269
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    • 1997
  • The purpose of this study is to survey the shape finding of the plane truss structures under the prescribed displacement mode by the shape analysis. The shape analysis is peformed by the existence condition of a solution and Moore-Penrose generalized inverse matrix, and the prescribed displacement mode is the homologous deformation of structures. The shape analysis of structures is a kind of inverse problem and become the problem of a nonlinear equation. Newton-Raphson method is used to improve the accuracy of approximated solution. To prove the accuracy and the effectiveness of this method, four different shape examples are analyzed.

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Reasonably completed state assessment of the self-anchored hybrid cable-stayed suspension bridge: An analytical algorithm

  • Kai Wang;Wen-ming Zhang;Jie Chen;Zhe-hong Zhang
    • Structural Engineering and Mechanics
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    • v.90 no.2
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    • pp.159-175
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    • 2024
  • In order to solve the problem of calculating the reasonable completed bridge state of a self-anchored hybrid cable-stayed suspension bridge (SA-HCSB), this paper proposes an analytical method. This method simplifies the main beam into a continuous beam with multi-point rigid supports and solves the support reaction forces. According to the segmented catenary theory, it simultaneously solves the horizontal forces of the main span main cables and the stay cables and iteratively calculates the equilibrium force system on the main beam in the collaborative system bridge state while completing the shape finding of the main span main cable and stay cables. Then, the horizontal forces of the side span main cables and stay cables are obtained based on the balance of horizontal forces on the bridge towers, and the shape finding of the side spans are completed according to the segmented catenary theory. Next, the difference between the support reaction forces of the continuous beam with multiple rigid supports obtained from the initial and final iterations is used to calculate the load of ballast on the side span main beam. Finally, the axial forces and strains of each segment of the main beam and bridge tower are obtained based on the loads applied by the main cable and stay cables on the main beam and bridge tower, thereby obtaining analytical data for the bridge in the reasonable completed state. In this paper, the rationality and effectiveness of this analytical method are verified through a case study of a SA-HCSB with a main span of 720m in finite element analysis. At the same time, it is also verified that the equilibrium force of the main beam under the reasonably completed bridge state can be obtained through iterative calculation. The analytical algorithm in this paper has clear physical significance, strong applicability, and high accuracy of calculation results, enriching the shape-finding method of this bridge type.

Study on the Minimization of Shape Parameters by Reverse Design of an Axial Turbine Blade (축류형 터빈 익형의 역설계에 의한 최소 형상변수에 관한 연구)

  • Cho, Soo-Yong;Oh, Koon-Sup;Yoon, Eui-Soo;Choi, Bum-Seog
    • The KSFM Journal of Fluid Machinery
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    • v.3 no.4 s.9
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    • pp.30-37
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    • 2000
  • Several reverse design methods are developed and applied to the suction or pressure surface for finding design values of blade geometry for a given axial turbine blade. Re-designed blade profiles using shape parameters are compared with measured blade data. Essential shape parameters for blade design are induced by the procedure of reverse design for best fitting. Characteristics of shape parameters are evaluated through the system design method and restriction conditions of structural stability or aerodynamic flow loss. Some of shape parameters i.e blade radius or exit blade angle etc., are classified to weakly adjustable shape parameters, otherwise strongly adjustable shape parameters which would be applied for controlling blade shape. Average deviation values between the measured data and re-designed blade using shape parameters are calculated for each design method. Comparing with the average deviation for a given blade geometry, minimum shape parameters required to design a blade geometry are obtained.

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Fast Shape Matching Algorithm Based on the Improved Douglas-Peucker Algorithm (개량 Douglas-Peucker 알고리즘 기반 고속 Shape Matching 알고리즘)

  • Sim, Myoung-Sup;Kwak, Ju-Hyun;Lee, Chang-Hoon
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.10
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    • pp.497-502
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    • 2016
  • Shape Contexts Recognition(SCR) is a technology recognizing shapes such as figures and objects, greatly supporting technologies such as character recognition, motion recognition, facial recognition, and situational recognition. However, generally SCR makes histograms for all contours and maps the extracted contours one to one to compare Shape A and B, which leads to slow progress speed. Thus, this paper has made simple yet more effective algorithm with optimized contour, finding the outlines according to shape figures and using the improved Douglas-Peucker algorithm and Harris corner detector. With this improved method, progress speed is recognized as faster.