• Title/Summary/Keyword: Three-dimensional measurement system

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A study on analysis of the structure of green space by the types of urban residential areas (도시내 주거지 유형별 녹지구조분석에 관한 연구)

  • 송태갑;김은일
    • Journal of the Korean Institute of Landscape Architecture
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    • v.25 no.3
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    • pp.56-65
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    • 1997
  • This research was conducted to suggest some directions for desirable urban green space planning through 1) establishing a new classification system by examining the existing concept, problems and characteristics of green space and 2) defining the essence of green space environment and finding some analytical and evaluative methods through a clear establishment of functions, indicators of green space. In the research, measurements of the amount of green space was accompanied with measurements of green covered space, green volume, and the structure of greenery within the frame of vision. As result, three-dimensional measurement was possible, three-dimensional measurement was possible, which turned out to be more effective than the existing 2-dimensional measuring method. It is found that the ratio of green covered space is to proportional to the ratio of green volume in this study. Therefore in green space planning process it is desirable to consider the ratio of green volume all together.

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A Study on Developments of Three-dimensional Measurement System for Flow-Structure Interactions using Digital Image Processing (디지털 영상처리기술을 이용한 비접촉식 유체-구조 연동운동3차원 측정시스템 개발에 관한 연구)

  • DOH DEOG-HEE;SANG JI-WOONG;HWANG TAE-GYU;CHO YONG-BEOM;PYEON YONG-BEOM
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.274-278
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    • 2004
  • A simultaneous measurement system that can analyze the flaw-structure interactions has been developed This system consists of four CCD cameras, two for capturing instantaneous flaw fields and two for tracking a solid body. The three-dimensional vector fields around a cylinder are measured while the motion of the cylinder forced by the flow field is measured simultaneously with the constructed system The cylinder is pended in the working fluid of a water channel and the surface of the working fluid is forced sinusoidal to make the cylinder bounced Reynolds number for the mean main stream is about l000. The interaction between the flaw fields and the cylinder motion is examined quantitatively.

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Phase calcuation error analysis of 3D shape measurement system using phase-shifted fringe projection method (위상이동 간섭무늬 투영을 이용한 3차원 형상측정 시스템의 위상계산오차 해석)

  • 류현미;김석성;홍석경;연규황
    • Korean Journal of Optics and Photonics
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    • v.13 no.3
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    • pp.182-188
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    • 2002
  • We have analyzed the phase-calculation-error of a three-dimensional shape measurement system using the projection of phase shifted fringe patterns. In this study, we have dealt various errors; an error caused by the variation of quantization levels, an error caused by the defocus of fringe pattern projected images, an error caused by phase-shifting errors, an error caused by the intensity variation of the background and modulation amplitude of fringe pattern projected images during the projection of multiple patterns, an error caused by the distortion of sinusoidal shape of a fringe pattern. The results will contribute to the design of a three-dimensional shape measurment system and give an important meaning to the calculation and the analysis of the accuracy of a system.

A Study on the Development of a Three-dimensional Measurement System for Flow-Structure Interaction Using Digital Image Processing (디지털영상처리기술을 이용한 비접촉식 유체-구조물 연동운동 3차원 측정시스템 개발에 관한 연구)

  • DOH DEOG-HEE;JO HYO-JAE;SANG JI-WOONG;HWANG TAE-GYU;CHO YONG-BEOM;PYEONTN YONG-BEOM
    • Journal of Ocean Engineering and Technology
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    • v.18 no.4 s.59
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    • pp.1-7
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    • 2004
  • A simultaneous measurement system that can analyze the flow-structure interaction has been developed. This system consists of four CCD cameras, two for capturing instantaneous flow fields and two for tracking a solid body. The three-dimensional vector fields around a cylinder are measured, while the motion of the cylinder forced by the flow field is measured, simultaneously, with the constructed system. The cylinder is suspended in the working fluid of a water channel, and the surface of the working fluid is forced sinusoidally to make the cylinder bounced. Reynolds number for the mean main stream is about 3500. The interaction between the flow fields and the cylinder motion is examined quantitatively.

Two-Dimensional Navigation Error for Geometry of Landmark in Line-Of-Sight Measurement Based Vision Navigation System (시선각 측정기반 비전항법시스템에서 랜드마크의 기하학적 배치에 대한 2차원 항법오차)

  • Kim, Young-Sun;Ji, Hyun-Min;Hwang, Dong-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.3
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    • pp.479-484
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    • 2012
  • Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.

Three-dimensional Flow Structure inside a Plastic Microfluidic Element (미소유체요소 내부유동의 3차원 측정 및 수치해석)

  • Lee Inwon;An Kwang Hyup;Nam Young Sok;Lee In-seop
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.419-422
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    • 2002
  • A three-dimensional inlet flow structure inside a microfluidic element has been investigated using a micro-PIV(particle image velocimetry) measurement as well as a numerical analysis. The present study employs a state-of-art micro-PIV system which consists of epi-fluorescence microscope, 620nm diameter fluorescent seed particles and an 8-bit megapixel CCD camera. For the numerical analysis, a commercial software CFD-ACE+(V6.6) was employed for comparison with experimental data. Fixed pressure boundary condition and a 39900 structured grid system was used for numerical analysis. Velocity vector fields with a resolution of $6.7{\times}6.7{\mu}m$ has been obtained, and the attention has been paid on the effect of varying measurement conditions of particle diameter and particle concentration on the resulting PIV results. In this study, the microfluidic elements were fabricated on plastic chips by means of MEMS processes and a subsequent melding process.

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Development of Holographic Particle Velocimetry System and Its Application to Spray Droplets (홀로그래피 입자속도 측정시스템의 개발과 분무 액적에의 적용)

  • Choo, Y.J.;Kang, B.S.
    • Journal of ILASS-Korea
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    • v.10 no.3
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    • pp.17-28
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    • 2005
  • The Holographic Particle Velocimetry system can be a promising optical tool for the measurements of three dimensional particle velocities. In this study, diffused illumination holographic system to measure the sizes and 3D velocities of moving particles based on automatic image processing was developed. First of all basic optical systems for pulse laser recording, continuous laser reconstruction, and image acquisition, were constructed. To determine the position of particles in the optical axis, new three auto-focusing parameters(AEP), namely, Correlation Coefficient, Sharpness Index, and Depth Intensity were introduced and verified. The developed system was applied to spray droplets to validate the capability of the system. Three dimensional positions of particles viewed from two sides were decided using AFP and then 3D velocities of Particles were extracted by particle tracking algorithm. Comparison of measurement results of sizes and 3D velocities of particles with those obtained by laser instrument, PDPA, showed good consistency of the developed holographic system.

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Approximate and Three-Dimensional Modeling of Brightness Levels in Interior Spaces by Using Artificial Neural Networks

  • Sahin, Mustafa;Oguz, Yuksel;Buyuktumturk, Fuat
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1822-1829
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    • 2015
  • In this study, artificial neural networks were used to determine the intensity of brightness in interior spaces. The illumination elements to illuminate indoor spaces were considered, not individually, but as a system. So, during the planned maintenance periods of an illumination system, after its design and installation, simple brightness level measurements must be taken. For a three-dimensional evaluation of the brightness level in indoor spaces in a speedy and accurate manner, the obtained brightness level measurement results and artificial neural network model were used. Upon estimation of the most suitable brightness level for indoor spaces by using the artificial neutral network model, the energy demands required by the illumination elements decreased. Consequently, in this study, with estimations of brightness levels, the extent to which the artificial neutral networks become successful was observed and more correct results have been obtained in terms of both economy and usage.

Validity and Reliability of an Inertial Measurement Unit-Based 3D Angular Measurement of Shoulder Joint Motion

  • Yoon, Tae-Lim
    • The Journal of Korean Physical Therapy
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    • v.29 no.3
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    • pp.145-151
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    • 2017
  • Purpose: The purpose of this study was to investigate the validity and reliability of the measurement of shoulder joint motions using an inertial measurement unit (IMU). Methods: For this study, 33 participants (32 females and 1 male) were recruited. The subjects were passively positioned with the shoulder placed at specific angles using a goniometer (shoulder flexion $0^{\circ}-170^{\circ}$, abduction $0^{\circ}-170^{\circ}$, external rotation $0^{\circ}-90^{\circ}$, and internal rotation $0^{\circ}-60^{\circ}$ angles). Kinematic data on the shoulder joints were simultaneously obtained using IMU three-dimensional (3D) angular measurement (MyoMotion) and photographic measurement. Test-retest reliability and concurrent validity were examined. Results: The MyoMotion system provided good to very good relative reliability with small standard error of measurement (SEM) and minimal detectable change (MDC) values from all three planes. It also presented acceptable validity, except for some of shoulder flexion, shoulder external rotation, and shoulder abduction. There was a trend for the shoulder joint measurements to be underestimated using the IMU 3D angular measurement system compared to the goniometer and photo methods in all planes. Conclusion: The IMU 3D angular measurement provided a reliable measurement and presented acceptable validity. However, it showed relatively low accuracy in some shoulder positions. Therefore, using the MyoMotion measurement system to assess shoulder joint angles would be recommended only with careful consideration and supervision in all situations.

Development of a Customized Helmet Design System for Patients with Plagiocephaly (사두증 환자를 위한 맞춤형 헬멧 몰드 디자인 시스템 개발)

  • Kang, Yeonghoon;Park, Hyeryeon;Kim, Sungmin
    • Fashion & Textile Research Journal
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    • v.24 no.4
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    • pp.443-450
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    • 2022
  • This study developed a three-dimensional helmet mold design software that can design helmets for treating the infant plagiocephaly (flat head syndrome) using three-dimensional head scan data. For this, the three-dimensional head data of sixth SizeKorea body measurement project as well as the data produced by a head modeling software were used to prepare the head shape data of plagiocephaly patients. A total of 14 landmarks and 10 dimensions of heads required for helmet mold shape design and plagiocephaly diagnosis were automatically measured using an anthropometric analysis software. Using the software developed in this study, plagiocephaly can be diagnosed not only visually by three-dimensional head data visualization but also quantitatively by calculating the medically defined indices such as cranial index, which measures the proportions of the head, and the cranial vault asymmetry index, which measures the asymmetry of the head. The basic shape of the helmet mold was automatically generated based on the head scan data. Additionally, it is possible to fine tune the shape of the mold to reflect individual characteristics by using a free form deformation technique. Finally, the designed helmet mold was converted into the data that can be printed on a three-dimensional printer for generating the actual prototype.