• Title/Summary/Keyword: 구경

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Analysis of Standard Cost and the Construction Period Applied TBM Excavation Method (TBM 굴착 공법 적용 구경별 표준 공사비 및 공사기간 분석 연구)

  • Park, Hong Tae
    • Journal of the Society of Disaster Information
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    • v.8 no.4
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    • pp.319-327
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    • 2012
  • This research collected work drilling report of TBM method site developed by WRITH company to TBM equipment company in Germany and analyzed work operating productivity. Based the data analyzed TBM operating productivity, This research derived and presented excavation speed(m/day) by TBM diameter (2.6m, 3.0m, 3.5m, 5.0m, 8.0m) and rock. Also, based on the excavation speed(m/day) by TBM diameter, This research estimated a day direct construction cost and total direct construction costs by applying a direct construction cost which spent on per 1m. Based on hard rock 40.0%, soft rock 30.0%, usually rock 20%, weathered rock 10.0%, TBM boring velocity, m per cost, total construction period shall estimate the construction cost and the construction period by the effective use by diameter when future applying TBM method to the basic planning stages and in the preliminary design phase.

An Experimental Study on a Discharge Pressure, Flow Rate and Foam Discharge Concentration through the Nozzle According to the Foam Suction Nipple Diameter (노즐 구경에 따른 포 수용액의 압력과 유량 및 농도 변화에 관한 실험적 연구)

  • Jang, Kyung-Nam;Lee, Maing-Ro;Park, Bong-Rae;Yun, Ki-Jo;Baek, Eun-Sun
    • Fire Science and Engineering
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    • v.29 no.2
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    • pp.84-91
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    • 2015
  • The purpose of this study is to suggest the reasonable model of the caliber in suction nozzle, the pressure of suction nozzle, and the flow rate about foam system of line proportioner type using in the pumpcar. To test this, the experimental study was accomplished on the ground of the standards for the Performance Certification and Product Inspection of Foam Fire-extinguishing Chemical Mixing Machine. Aqueous Film Forming Foam in 3% and pipe type air foam nozzle with line proportioner FE 40 type were used. Test result showed that the pressure of suction nozzle within the limits between 0.25 MPa and 0.35 MPa was appropriate when the caliber in suction nozzle is 4 mm. Also, the pressure of suction nozzle within the limits between 0.45 MPa and 0.60 MPa was appropriate in the higher pressure than 4 mm when the caliber in suction nozzle is 5 mm.

Real-Time 3D Ultrasound Imaging Method Using a Cross Array Based on Synthetic Aperture Focusing: II. Linear Wave Front Transmission Approach (합성구경 기반의 교차어레이를 이용한 실시간 3차원 초음파 영상화 기법 : II. 선형파면 송신 방법)

  • 김강식;송태경
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.403-414
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    • 2004
  • In the accompanying paper, we proposed a real. time volumetric imaging method using a cross array based on receive dynamic focusing and synthetic aperture focusing along lateral and elevational directions, respetively. But synthetic aperture methods using spherical waves are subject to beam spreading with increasing depth due to the wave diffraction phenomenon. Moreover, since the proposed method uses only one element for each transmission, it has a limited transmit power. To overcome these limitations, we propose a new real. time volumetric imaging method using cross arrays based on synthetic aperture technique with linear wave fronts. In the proposed method, linear wave fronts having different angles on the horizontal plane is transmitted successively from all transmit array elements. On receive, by employing the conventional dynamic focusing and synthetic aperture methods along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. Mathematical analysis and computer simulation results show that the proposed method can provide uniform elevational resolution over a large depth of field. Especially, since the new method can construct a volume image with a limited number of transmit receive events using a full transmit aperture, it is suitable for real-time 3D imaging with high transmit power and volume rate.

Rotational Prism Stitching Interferometer for High-resolution Surface Testing (고해상도 표면 측정을 위한 회전 프리즘 정합 간섭계)

  • In-Ung Song;Woo-Sung Kwon;Hagyong Khim;Yun-Woo Lee;Jong Ung Lee;Ho-Soon Yang
    • Korean Journal of Optics and Photonics
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    • v.34 no.3
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    • pp.117-123
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    • 2023
  • The size of an optical surface can significantly affect the performance of an optical system, and high spatial frequency errors have a greater impact. Therefore, it is crucial to measure the surface figure error with high frequency. To address this, a new method called rotational prism stitching interferometer (RPSI) is proposed in this study. The RPSI is a type of stitching interferometer that enhances spatial resolution, but it differs from conventional stitching interferometers in that it does not require the movement of either the mirror tested or the interferometer itself to obtain sub-aperture interferograms. Instead, the RPSI uses a beam expander and a rotating Dove prism to select particular sub-apertures from the entire aperture. These sub-apertures are then stitched together to obtain a full-aperture result proportional to the square of the beam expander's magnification. The RPSI's effectiveness was demonstrated by measuring a 40 mm diameter spherical mirror using a three-magnification beam expander and comparing the results with those obtained from a commercial interferometer. The RPSI achieved surface testing results with nine times higher sampling density than the interferometer alone, with a small difference of approximately 1 nm RMS.

Performance Prediction for Plenoptic Microscopy Under Numerical Aperture Unmatching Conditions (수치 구경 불일치 플렌옵틱 현미경 성능 예측 방안 연구)

  • Ha Neul Yeon;Chan Lee;Seok Gi Han;Jun Ho Lee
    • Korean Journal of Optics and Photonics
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    • v.35 no.1
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    • pp.9-17
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    • 2024
  • A plenoptic optical system for microscopy comprises an objective lens, tube lens, microlens array (MLA), and an image sensor. Numerical aperture (NA) matching between the tube lens and MLA is used for optimal performance. This paper extends performance predictions from NA matching to unmatching cases and introduces a computational technique for plenoptic configurations using optical analysis software. Validation by fabricating and experimenting with two sample systems at 10× and 20× magnifications resulted in predicted spatial resolutions of 12.5 ㎛ and 6.2 ㎛ and depth of field (DOF) values of 530 ㎛ and 88 ㎛, respectively. The simulation showed resolutions of 11.5 ㎛ and 5.8 ㎛, with DOF values of 510 ㎛ and 70 ㎛, while experiments confirmed predictions with resolutions of 11.1 ㎛ and 5.8 ㎛ and DOF values of 470 ㎛ and 70 ㎛. Both formula-based prediction and simulations yielded similar results to experiments that were suitable for system design. However, regarding DOF values, simulations were closer to experimental values in accuracy, recommending reliance on simulation-based predictions before fabrication.

Experimental Study on Performance of Mini -Sprinkler -( 1 ) Sprinkling Flow Rate and Sprinkling Intensity Pattern (미니 스프링클러의 살수 성능실험-(1)살수량과 거리별 살수강도)

  • 서상룡;유수남;성제훈
    • Journal of Bio-Environment Control
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    • v.5 no.2
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    • pp.194-201
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    • 1996
  • A series of experiments to analyse and to compare performance of various types of mini-sprinkler was carried out. Twelve kinds of the sprinkler, which have various sizes of nozzle orifice diameter and structures of spreader, were selected to be tested. Flow (water sprinkling) rate and sprinkling intensity pattern from a sprinkler were measured as a first part of this study, and the results are as follows. Sprinkler flow rate of various sizes of nozzle orifice and applied water pressures could be predicted by Torricelli's theorem. Discharge coefficients of the Torricelli's theorem for the sprinkler nozzle of various sizes were determined by the experiment as 0.90- 0.95, 0.80-0.82 and 0.76-0.79 for 0.8, 1.2 and 1.6 mm of nozzle orifice diameter, respectively. Experiments on sprinkling intensity pattern resulted that nozzle orifice diameter and applied water pressure are major variables for uniformity of the sprinkling intensity. More uniform sprinklering patterns were noted with smaller nozzle orifice diameter of a sprinkler and at lower sprinkling pressure. Besides the variables, structure of spreader of a sprinkler is also an important variable for the uniformity of sprinkling intensity.

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Development of a Coded-aperture Gamma Camera for Monitoring of Radioactive Materials (방사성 물질 감시를 위한 부호화 구경 감마카메라 개발)

  • Cho, Gye-Seong;Shin, Hyung-Joo;Chi, Yong-Ki;Yoon, Jeong-Hyoun
    • Journal of Radiation Protection and Research
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    • v.29 no.4
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    • pp.257-261
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    • 2004
  • A coded-aperture gamma camera was developed to increase the sensitivity of a pin hole camera made with a pixellated CsI(Tl) scintillator and a position-sensitive photomultiplier tube. The modified round-hole uniformly redundant array of pixel size $13{\times}11$ was chosen as a coded mask considering the detector spatial resolution. The performance of the coded-aperture camera was compared with the pin hole camera using various forms of Tc-99m source to see the improvement of signal-to-noise ratio or the improvement of the sensitivity. The image quality is much improved despite of a slight degradation of the spatial resolution. Though the camera and the test were made for low energy case, but the concept of the coded-aperture gamma camera could be effectively used for the radioactive environmental monitoring and other applications.

Aperture Correction using Distance-Dependent Backprojection for SPECT Images (거리 의존적 역투사를 이용한 SPECT 영상 구경보정)

  • Lee, Nam-Yong
    • Journal of Korea Multimedia Society
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    • v.11 no.4
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    • pp.434-442
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    • 2008
  • The parallel beam SPECT acquires projection data by using parallel hole collimators in conjunction with photon detectors. Those projection data of the parallel beam SPECT are, however, contaminated by the distance dependent blurring because of the inaccuracy of the point response function of the collimator that is used to define the range of directions where photons can be detected. Thus an efficient aperture correction is required. In this paper we propose a distance dependent backprojection method to overcome the time limitation of iterative aperture correction methods and the performance limitation of Fourier-Distance Relation based method. The proposed method achieves aperture correction and fast image reconstruction by replacing the distance independent backprojection of the direct image reconstruction with the distance dependent one. We conducted several simulations to compare the performance of the proposed method with that of the conventional Fourier-Distance Relation based method. The simulation result shows that the proposed method outperforms the Fourier-Distance Relation based method in spatial resolution and robustness against noise.

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A Study for Non-paraxial Diffraction Caused by Curved Principal Planes (주요면의 만곡에 따른 비근축 회절에 대한 연구)

  • Lee, Jong Ung
    • Korean Journal of Optics and Photonics
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    • v.23 no.1
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    • pp.1-5
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    • 2012
  • According to the paraxial diffraction theory, diffractions of optical systems which have the same wavelength and numerical aperture are always the same, independent of lateral magnification. But the diffractions for optical systems with different magnifications are varied due to the non-paraxial diffraction effect on the imaging of high NA optics. In this study, the non-paraxial diffraction effect is interpreted as a phenomena caused by curved principal planes. Pupil functions and modulation transfer functions of aplanatic conic mirrors are examined as a function of lateral magnification.