• Title/Summary/Keyword: Field of view

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Ultra Precision Machining Technology Development of Subminiature Optics of Proximity and Wide Field of View (초정밀 가공기를 이용한 근접초소형 광시야각 광학계 기술 개발)

  • Kim, M.S.;Yang, S.C.;Kim, H.S.;Kim, G.H.
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.4
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    • pp.96-101
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    • 2008
  • Due to improve form accuracy and surface roughness of a aspheric lens core that is made of Ni, the study is carried out on localization about a Subminiature Optics of Proximity and Wide Field of View. The required form accuracy P-V $0.2{\mu}m$ and surface roughness is Ra 10 nm. The design of experiment(DOE) is adopted to find a optimal cutting conditions which are spindle speed, depth of cut, feedrate. Finally, the effects of this study are replacing importation and strengthening competitiveness through the localization of the Subminiature Optics of Proximity and Wide Field of View.

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A Novel Visual Servoing Approach For Keeping Feature Points Within The Field-of-View (특징점이 Field of View를 벗어나지 않는 새로운 Visual Servoing 기법)

  • Park, Do-Hwan;Yeom, Joon-Hyung;Park, Noh-Yong;Ha, In-Joong
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.322-324
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    • 2007
  • In this paper, an eye-in-hand visual servoing strategy for keeping feature points within the FOV(field-of-view) is proposed. We first specify the FOV constraint which must be satisfied to keep the feature points within the FOV. It is expressed as the inequality relationship between (i) the LOS(jine-of-sight) angles of the center of the feature points from the optical axis of the camera and (ii) the distance between the object and the camera. We then design a nonlinear feedback controller which decouples linearly the translational and rotational control loops. Finally, we show that appropriate choice of the controller gains assures to satisfy the FOV constraint. The main advantage of our approach over the previous ones is that the trajectory of the camera is smooth and circular-like. Furthermore, ours can be applied to the large camera displacement problem.

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Voxel-wise UV parameterization and view-dependent texture synthesis for immersive rendering of truncated signed distance field scene model

  • Kim, Soowoong;Kang, Jungwon
    • ETRI Journal
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    • v.44 no.1
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    • pp.51-61
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    • 2022
  • In this paper, we introduced a novel voxel-wise UV parameterization and view-dependent texture synthesis for the immersive rendering of a truncated signed distance field (TSDF) scene model. The proposed UV parameterization delegates a precomputed UV map to each voxel using the UV map lookup table and consequently, enabling efficient and high-quality texture mapping without a complex process. By leveraging the convenient UV parameterization, our view-dependent texture synthesis method extracts a set of local texture maps for each voxel from the multiview color images and separates them into a single view-independent diffuse map and a set of weight coefficients for an orthogonal specular map basis. Furthermore, the view-dependent specular maps for an arbitrary view are estimated by combining the specular weights of each source view using the location of the arbitrary and source viewpoints to generate the view-dependent textures for arbitrary views. The experimental results demonstrate that the proposed method effectively synthesizes texture for an arbitrary view, thereby enabling the visualization of view-dependent effects, such as specularity and mirror reflection.

MCNP-polimi simulation for the compressed-sensing based reconstruction in a coded-aperture imaging CAI extended to partially-coded field-of-view

  • Jeong, Manhee;Kim, Geehyun
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.199-207
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    • 2021
  • This paper deals with accurate image reconstruction of gamma camera using a coded-aperture mask based on pixel-type CsI(Tl) scintillator coupled with silicon photomultipliers (SiPMs) array. Coded-aperture imaging (CAI) system typically has a smaller effective viewing angle than Compton camera. Thus, if the position of the gamma source to be searched is out of the fully-coded field-of-view (FCFOV) region of the CAI system, artifacts can be generated when the image is reconstructed by using the conventional cross-correlation (CC) method. In this work, we propose an effective method for more accurate reconstruction in CAI considering the source distribution of partially-coded field-of-view (PCFOV) in the reconstruction in attempt to overcome this drawback. We employed an iterative algorithm based on compressed-sensing (CS) and compared the reconstruction quality with that of the CC algorithm. Both algorithms were implemented and performed a systematic Monte Carlo simulation to demonstrate the possiblilty of the proposed method. The reconstructed image qualities were quantitatively evaluated in sense of the root mean square error (RMSE) and the peak signal-to-noise ratio (PSNR). Our simulation results indicate that the proposed method provides more accurate location information of the simulated gamma source than the CC-based method.

Tolerance Analysis and Compensation Method Using Zernike Polynomial Coefficients of Omni-directional and Fisheye Varifocal Lens

  • Kim, Jin Woo;Ryu, Jae Myung;Kim, Young-Joo
    • Journal of the Optical Society of Korea
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    • v.18 no.6
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    • pp.720-731
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    • 2014
  • There are many kinds of optical systems to widen a field of view. Fisheye lenses with view angles of 180 degrees and omni-directional systems with the view angles of 360 degrees are recognized as proper systems to widen a field of view. In this study, we proposed a new optical system to overcome drawbacks of conventional omni-directional systems such as a limited field of view in the central area and difficulties in manufacturing. Thus we can eliminate the undesirable reflection components of the omni-directional system and solve the primary drawback of the conventional system. Finally, tolerance analysis using Zernike polynomial coefficients was performed to confirm the productivity of the new optical system. Furthermore, we established a method of optical axis alignment and compensation schemes for the proposed optical system as a result of tolerance analysis. In a sensitivity calculation, we investigated performance degradation due to manufacturing error using Code V(R) macro function. Consequently, we suggested compensation schemes using a lens group decentering. This paper gives a good guidance for the optical design and tolerance analysis including the compensation method in the extremely wide angle system.

A MAGNETOHYDRODYNAMIC MODEL FOCUSED ON THE CONFIGURATION OF MAGNETIC FIELD RESPONSIBLE FOR A SOLAR PENUMBRAL MICROJET

  • Magara, Tetsuya
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.49.2-49.2
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    • 2010
  • In order to understand the configuration of magnetic field producing a solar penumbral microjet that was recently discovered by Hinode, we performed a magnetohydrodynamic simulation reproducing a dynamic process of how that configuration is formed in a modeled solar penumbral region. A horizontal magnetic flux tube representing a penumbral filament is placed in a stratified atmosphere containing the background magnetic field that is directed in a relatively vertical direction. Between the flux tube and the background field there forms the intermediate region in which the magnetic field has a transitional configuration, and the simulation shows that in the intermediate region magnetic reconnection occurs to produce a clear jet- like structure as suggested by observations. The result that a continuous distribution of magnetic field in three-dimensional space gives birth to the intermediate region producing a jet presents a new view about the mechanism of a penumbral microjet, compared to a simplistic view that two field lines, one of which represents a penumbral filament and the other the background field, interact together to produce a jet. We also discuss the role of the intermediate region in protecting the structure of a penumbral filament subject to microjets.

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The Greenery Evaluation Study from View of Inhabitant in Case of Arpartment House Complexes Encircled by the Fields near Seoul in Korea (전원고립형 공동주택단지의 녹지에 대한 거주자평가에 관한 연구)

  • Kim, Yung-Min;Jang, Han-Seub;Kim, Ick-Hwan
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2004.11a
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    • pp.183-188
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    • 2004
  • In the suburbs near the capital area in Korea, many apartment house complexes are dotted that encircled by field. These apartment house complexes encircled by field, have not park and are abutting on the field, unlike large scale new town. This study is aimed to clear the characteristic of field around these apartment house complexes, consists in development the suburbs near the capital area. As a method of study we conducted greenery evaluation from view of Inhabitant by questionnaire survey. We concluded as follows: inhabitants attach importance to the nature around apartment house complex when move into that; inhabitants are satisfied and feel nature about the field; inhabitants tend to take field as a sight; inhabitants need low-rise development for harmony with field.

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Implementation for Modbus/RTU Protocol Using LabVIEW (LabVIEW를 이용한 Modbus/RTU 프로토콜 구현)

  • Jeong, Tae-il;Lee, Tae-oh;Kim, Gwan-hyung;Kim, Hyun-soo;Lee, Hyung-ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.1054-1057
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    • 2015
  • Real time processing is important in the industrial field. In this paper, we implement for Modbus/RTU(Remote Terminal Unit) protocol using LabVIEW based on serial communication. In other to obtain the experimental data from torque sense and voltage/current meter, Modbus/RTU protocol is implemented by LabVIEW tool. Mechanical loss can be calculated by torque, RPM, voltage, and current. Source code consist of panel and block diagram. We confirmed these source code can be applied in industrial field.

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Fast MR Imaging Technique by Using Locally-Linear Gradient Field (부분적인 경사자계를 이용한 고속 자기공명 영상촬영기법)

  • 양윤정;이종권
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.93-98
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    • 1996
  • The purpose of this paper is to propose a new localized imaging method of reduced imaging time luting a locally-linear gradient. Since most fast MR(Magnetic Resonance) imaging methods need the whole $\kappa$-space(Spatial frequency space) data corresponding to the whole imaging area, there are limitstions in reducing the minimum imaging time. The imaging method proposed in this paper uses a specially-made gradient coil generating a local ramp-shape field and uniform field outside of the imaging areal Conventional imaging sequences can be used without any RF/gradient pulse sequence modifiestions except the change in the number of encoding steps and the field of view.

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Study on Distortion and Field of View of Contents in VR HMD

  • Son, Hojun;Jeon, Hyoung joon;Kwon, Soonchul
    • International journal of advanced smart convergence
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    • v.6 no.1
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    • pp.18-25
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    • 2017
  • Recently, VR HMD (virtual reality head mounted display) has been utilized for virtual training, entertainment, vision therapy, and optometry. In particular, virtual reality contents are increasingly used for vision therapy and optometry. Accordingly, high-quality virtual reality contents such as a natural vision of life is required. Therefore, it is necessary to study the content production according to the optical characteristics of the VR HMD. The purpose of this paper is to suggest a proper FOV (field of view) of contents according to the distortion rate. We produced virtual reality contents and obtained distorted images by virtual camera. The distortion rate is calculated by using the distorted image. It is proved that the optimal FOV of the VR content with the minimum distortion is $90{\sim}100^{\circ}$. The results of this study are expected to be applied to the production of high quality contents.