• Title/Summary/Keyword: linear primitives

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A Linear Window Operator Based Upon the Algorithm Decomposition (알고리즘 분해방법을 이용한 Linear Window Operator의 구현)

  • 정재길
    • The Journal of Information Technology
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    • v.5 no.1
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    • pp.133-142
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    • 2002
  • This paper presents an efficient implementation of the linear window operator. I derived computational primitives based upon a block state space representation. The computational primitive can be implemented as a data path for a programmable processor, which can be used for the efficient implementation of a linear window operator. A multiprocessor architecture is presented for the realtime processing of a linear window operator. The architecture is designed based upon the data partitioning technique. Performance analysis for the various block size is provided.

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Imitation Learning of Bimanual Manipulation Skills Considering Both Position and Force Trajectory (힘과 위치를 동시에 고려한 양팔 물체 조작 솜씨의 모방학습)

  • Kwon, Woo Young;Ha, Daegeun;Suh, Il Hong
    • The Journal of Korea Robotics Society
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    • v.8 no.1
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    • pp.20-28
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    • 2013
  • Large workspace and strong grasping force are required when a robot manipulates big and/or heavy objects. In that situation, bimanual manipulation is more useful than unimanual manipulation. However, the control of both hands to manipulate an object requires a more complex model compared to unimanual manipulation. Learning by human demonstration is a useful technique for a robot to learn a model. In this paper, we propose an imitation learning method of bimanual object manipulation by human demonstrations. For robust imitation of bimanual object manipulation, movement trajectories of two hands are encoded as a movement trajectory of the object and a force trajectory to grasp the object. The movement trajectory of the object is modeled by using the framework of dynamic movement primitives, which represent demonstrated movements with a set of goal-directed dynamic equations. The force trajectory to grasp an object is also modeled as a dynamic equation with an adjustable force term. These equations have an adjustable force term, where locally weighted regression and multiple linear regression methods are employed, to imitate complex non-linear movements of human demonstrations. In order to show the effectiveness our proposed method, a movement skill of pick-and-place in simulation environment is shown.

Algorithms for Multi-sensor and Multi-primitive Photogrammetric Triangulation

  • Shin, Sung-Woong;Habib, Ayman F.;Ghanma, Mwafag;Kim, Chang-Jae;Kim, Eui-Myoung
    • ETRI Journal
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    • v.29 no.4
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    • pp.411-420
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    • 2007
  • The steady evolution of mapping technology is leading to an increasing availability of multi-sensory geo-spatial datasets, such as data acquired by single-head frame cameras, multi-head frame cameras, line cameras, and light detection and ranging systems, at a reasonable cost. The complementary nature of the data collected by these systems makes their integration to obtain a complete description of the object space. However, such integration is only possible after accurate co-registration of the collected data to a common reference frame. The registration can be carried out reliably through a triangulation procedure which considers the characteristics of the involved data. This paper introduces algorithms for a multi-primitive and multi-sensory triangulation environment, which is geared towards taking advantage of the complementary characteristics of spatial data available from the above mentioned sensors. The triangulation procedure ensures the alignment of involved data to a common reference frame. The devised methodologies are tested and proven efficient through experiments using real multi-sensory data.

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Photogrammetric Georeferencing Using LIDAR Linear and Areal Features

  • HABIB Ayman;GHANMA Mwafag;MITISHITA Edson
    • Korean Journal of Geomatics
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    • v.5 no.1
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    • pp.7-19
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    • 2005
  • Photogrammetric mapping procedures have gone through major developments due to significant improvements in its underlying technologies. The availability of GPS/INS systems greatly assist in direct geo-referencing of the acquired imagery. Still, photogrammetric datasets taken without the aid of positioning and navigation systems need control information for the purpose of surface reconstruction. Point features were, and still are, the primary source of control for the photogrammetric triangulation although other higher-order features are available and can be used. LIDAR systems supply dense geometric surface information in the form of three dimensional coordinates with respect to certain reference system. Considering the accuracy improvement of LIDAR systems in the recent years, LIDAR data is considered a viable supply of photogrammetric control. To exploit LIDAR data, new challenges are poised concerning the representation and reference system by which both the photogrammetric and LIDAR datasets are described. In this paper, registration methodologies will be devised for the purpose of integrating the LIDAR data into the photogrammetric triangulation. Such registration methodologies have to deal with three issues: registration primitives, transformation parameters, and similarity measures. Two methodologies will be introduced that utilize straight-line and areal features derived from both datasets as the registration primitives. The first methodology directly incorporates the LIDAR lines as control information in the photogrammetric triangulation, while in the second methodology, LIDAR patches are used to produce and align the photogrammetric model. Also, camera self-calibration experiments were conducted on simulated and real data to test the feasibility of using LIDAR patches for this purpose.

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REGISTRATION OF IKONOS-2 GEO-LEVEL SATELLITE IMAGERY USING ALS DATA;BY USING LINEAR FEATURES AS REGISTRATION PRIMITIVES

  • Lee, Jae-Bin;Song, Woo-Seok;Lee, Chang-No;Yu, Ki-Yun;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.14-17
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    • 2007
  • To make use of surveying data obtained from different sensors and different techniques in a common reference frame, it is a pre-requite step to register them in a common coordinate system. For this purpose, we have developed a methodology to register IKONOS-2 Satellite Imagery using ALS data. To achieve this, conjugate features from these data should be extracted in advance. In the study, linear features are chosen as conjugate features because they can be accurately extracted from man-made structures in urban area, and more easily than point features from ALS data. Then, observation equations are established from similarity measurements of the extracted features. During the process, considering the characteristics of systematic errors in IKONOS-2 satellite imagery, the transformation function were selected and used. In addition, we also analyzed how the number of linear features and their spatial distribution used as control features affect the accuracy of registration. Finally, the results were evaluated statistically and the results clearly demonstrated that the proposed algorithms are appropriate to register these data.

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A Study on Assembly Part Recognition Using Part-Based Superquadric Model (부품 기반한 수퍼쿼드릭 모델을 이용한 기계부품 인식에 관한 연구)

  • 이선호;홍현기;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.4B
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    • pp.734-742
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    • 2000
  • This paper presents a new volumetric approach to 3D object recognition by using PBSM (part-based superquadric model). The assembly part object can be constructed with the set of volumetric primitives and the relationships between them. We describe volumetric characteristics of the model object with superquadric parameters. In addition, our model base has the relationships between volumetric primitives as well as the surface information : the surface type, the junction type between neighboring surfaces. These surface properties and relationships between parts are effectively used in recognition process. Our integrated method is robust to recognition of the identity, position, and orientation of randomly oriented assembly parts. Furthermore, we can reduce the effects of self-occlusion and non-linear shape changes according to viewpoint. In this paper, we show that our integrated method is robust to recognition of the identity, position, and orientation of randomly oriented assembly parts through experimental results.

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Volume Reconstruction by Cellboundary Representation for Medical Volume Visualization (의료영상 가시화를 위한 셀 경계 방식 체적 재구성 방법)

  • Choi, Young-Kyu;Lee, Ee-Taek
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.3
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    • pp.235-244
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    • 2000
  • This paper addresses a new method for constructing surface representation of 3D structures from a sequence of tomographic cross-sectional images, Firstly, we propose cell-boundary representation by transforming the cuberille space into cell space. A cell-boundary representation consists of a set of boundary cells with their 1-voxel configurations, and can compactly describe binary volumetric data. Secondly, to produce external surface from the cell-boundary representation, we define 19 modeling primitives (MP) including volumetric, planar and linear groups. Surface polygons are created from those modeling primitives using a simple table look-up operation. Comparing with previous method such as Marching Cube or PVP algorithm, our method is robust and does not make any crack in resulting surface model. Hardware implementation is expected to be easy because our algorithm is simple(scan-line), efficient and guarantees data locality in computation time.

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An Application of Screw Motions for Mechanical Assemblies (기계부품들의 조립 및 해체과정 설계를 위한 스크류이론의 응용)

  • 김재정
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.1
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    • pp.60-67
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    • 1997
  • CAD systems offer a variety of techniques for designing and rendering models of static 3D objects and even of mechanisms, but relatively few tools exist for interactively specifying arbitrary movements of rigid bodies through space. Such tools are essential, not only for artistic animation, but also, for planning and demonstrating assembly and disassembly procedure of manufactured products. A rigid body motion is a continuous mapping from the time domain to a set of positions. To relieve the designers from the burden of specifying this mapping in abstract mathematical terms, combinations of simple rigid motion primitives, such as linear translations or constant axis rotations, are often used. These simple motions are planar and thus ill-suited for approximating arbitrary motions in 3D-space. Instead, we propose the screw motion primitive, a special combination of linear translations and constant axis rotations, which has a simple geometric representation that can be automatically and unambiguously computed from the starting and ending positions of the moving body. Although, any two positions may be interpolated by an infinity of motions, we chose the screw motion for its relative generality and its computational advantages. The paper covers original algorithms for computing the screw motions from interpolated positions and envelopes of swept regions to predict collisions.

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A Study on a Power Transmission Line Mobile Robot for Bundled Conductor Navigation

  • Seok, Kwang-Ho;Kim, Yoon Sang
    • International journal of advanced smart convergence
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    • v.8 no.2
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    • pp.155-161
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    • 2019
  • We introduces a mobile robot that can navigate on a power transmission line arranged in bundled conductors. The designs of the proposed robot are performed for navigation on bundled conductors, and the navigation method for bundled conductors and obstacle avoidance are presented. The robot consists of 13 degrees of freedom (DOF) with a symmetrical structure for the left and right parts, including the four wheel joints. The navigation method is designed using a combination of three motion primitives such as linear motion of counterbalancing box, linear motion of robot arm, and rotational motion of wheel part. To examine the performance of the proposed robot, navigation simulations are conducted using $ADAMS^{TM}$. The robot navigations were simulated on obstacle environments that consisted of two- and four-conductor bundles. Based on the simulation results, the performance of the proposed robot was reviewed through the analysis of the trajectories of end-effectors. We confirmed that the proposed robot was capable of achieving optimal navigation on bundled conductors that included obstacles.