• Title/Summary/Keyword: 근거리 측정

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A Study on Near-Field to Far-Field Transformation Using Stratton-Chu Formula (Stratton-Chu 공식을 이용한 측정된 근거리장에서 원거리장으로의 변환에 관한 연구)

  • Lee, Jeong-Seok;Song, Tae-Lim;Du, Jin-Kyoung;Koo, Tae-Wan;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.3
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    • pp.316-323
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    • 2013
  • This paper deals with the near-field to far-field calculation for far-field characteristics of antenna and electromagnetic compatibility(EMC) testing. Since the conventional EMC testing process is inefficient such as measurements of the wide band signals and mega structures, Stratton-Chu formula is used to predict the far-field emission by simple and direct process. The usefulness of Stratton-Chu formula is verified by comparing to the analytic solution of the uniform distribution aperture in free-space. In order to inspect the far-fields and to get the near-field values, full-wave simulation solver is utilized. Through the full-wave simulation about the patch antenna, calculated far-field results from Stratton-Chu formula are proven. The predicted magnitudes of the far-field are in error by less than 6 %.

Vibration Displacements Measurement of Slope Models using Close Range Photogrammetry (근거리 사진측량을 이용한 사면모형 진동 변위 측정)

  • Jung, Sung-Heuk;Lee, Jae-Young;Choi, Suk-Keun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.6
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    • pp.561-568
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    • 2011
  • The purpose of this study is to measure displacements that occurs on a surface and interior of slope model and the shape when the slope is destroyed at vibration experiment of the slope model using close range photogrammetry. The circle targets and sphere targets are installed on a chamber and a slope model, while the earthquake wave are applied in regular time interval. The close range photogrammetric images are acquired in each displacements step until the slope model is destroyed. Those photos are processed by image processing method and the center points of targets are automatically extracted. Furthermore, the three-dimensional coordinates of targets are calculated by image orientation and bundle adjustment processing. As a result, amount of displacement at each level is precisely measured and provided the basic information for assessing the slope stability using three-dimensional measurement of the target movement and slope destruction.

Analysis of far & near distance of lateral phoria by various testing methods (검사 방법에 따른 원·근거리 수평사위의 분석)

  • Hong, Dong-Gyun;Jung, Han-Sub;Park, Sang-An
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.423-430
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    • 2004
  • This Study on three different methods which are Von Graefe test, Maddox Rod test and Howell card test of measuring far and near lateral phoria investigated. It reviewed that 420 subjects aged from 15 to 35 years old. The result were as follows; 1. Using Von Graefe lateral phoria measurement, they were measured 6% for orthophoria, 62% for exophoria, 32% for esophoria at far distance. 2. Using Von Graefe lateral phoria measurement, they were measured 2% for orthophoria, 74% for exophoria, 24% for esophoria at near distance. 3. Using Maddox Rod lateral phoria measurement, they 59% for exophoria, 37% for esophoria at far distance. 4. Using Maddox Rod lateral phoria measurement, they 67% for exophoria, 30% for esophoria at near distance. 5. Using Howell card lateral phoria measurement, they 60% for exophoria, 32% for esophoria at far distance. 6. Using Howell card lateral phoria measurement, they 69% for exophoria, 27% for esophoria at near distance.

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Correlation of Near Stereoacuity and Phoria, and Refractive Error (근거리 입체시와 사위 및 굴절이상의 상관관계)

  • Shim, Hyun-Suk;Kim, Sang-Hyun;Kim, Young-Cheong
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.1
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    • pp.67-73
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    • 2015
  • Purpose: This study was investigated the relationship between the male and female of near stereoacuity and phoria, and was examined the correlations between near stereoacuity and phoria and refractive error. Methods: Adult 83 (male 36, female 47, mean age $21.09{\pm}1.74$(19~29) years old) target was examined after full correction of refractive error. Near stereoacuity was measured by using Titmus-fly Stereotest(Stereo Optical Co., Inc., Chicago, IL, USA), and RANDOT Stereotest (Stereo Optical Co., Inc., Chicago, IL, USA), phoria was measured by using modified torrington method, at distance 40 cm. Results: In near stereoacuity, male was better good than female, and there was no difference between male and female (p>0.05). In near phoria, female was more higher than male, and there was a significant difference between male and female (p<0.05). Near stereoacuity by Titmus-fly test and Randot test result respectively was $262.17{\pm}562.43$ sec (second of arc) $243.08{\pm}68.04$ sec in esophoria, $148.42{\pm}269.54$ sec, $107.40{\pm}263.74$ sec in orthophoria, $113.94{\pm}152.46$ sec, $79.70{\pm}136.83$ sec in exophoria, there was a no difference between three phoria groups (p>0.05), and was a high correlation between phoria and near stereoacity(r=0.68). In addition, near stereoacuity in the refractive error respectively was $80.00{\pm}571.43$ sec, $68.75{\pm}36.82$ sec in myopia, $133.57{\pm}224.15$ sec, $93.14{\pm}214.95$ sec in hyperopia, $511.20{\pm}855.00$ sec, $511.4{\pm}855.60$ sec, there was a significant difference between three phoria groups (p<0.05). when was classfiied near stersoacuity into degree of refractive error, near stersoacuity was best in emmetropia, and was reduced when refractive error was highest in high degree myopia, and hyperopia. Conclusions: Titmus-fly Stereotest and RANDOT Stereotest result, near stereoacuity of adults, when esophoria and high degree refractive error, was reduced, there was a relationship between near stereoacuity with phoria, and refractive error. In this both stereotests if was bad when near stereoacuity can expect a phoria and refractive error.

Development of High-Sensitivity and Entry-Level Radiation Measuring Sensor Module (고감도 보급형 방사선 측정센서 모듈 개발)

  • Oh, Seung-Jin;Lee, Joo-Hyun;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.26 no.3
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    • pp.510-514
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    • 2022
  • In this paper, we propose the development of high-sensitivity low-end radiation measuring sensor module. The proposed measurement sensor module is a scintillator + photomultiplier(SiPM) sensor optimization structure design, amplification and filter and control circuit design for sensor driver, control circuit design including short-distance communication, sensor mechanism design and manufacturing, and GUI development applied to prototypes consists of, etc. The scintillator + photomultiplier(SiPM) sensor optimization structure design is designed by checking the characteristics of the scintillator and the photomultiplier (SiPM) for the sensor structure design. Amplification, filter and control circuit design for sensor driver is designed to process fine scintillation signal generated by radiation with a scintillator using SiPM. Control circuit design including short-distance communication is designed to enable data transmission through MCU design to support short-range wireless communication function and wired communication support. The sensor mechanism design and manufacture is designed so that the glare generated by wrapping a reflective paper (mirroring) on the outside of the plastic scintillator is reflected to increase the efficiency in order to transmit the fine scintillation signal generated from the plastic scintillator to the photomultiplier(SiPM). The GUI development applied to the prototype expresses the date and time at the top according to each screen and allows the measurement unit and time, seconds, alarm level, communication status, battery capacity, etc. to be expressed. In order to evaluate the performance of the proposed system, the results of experiments conducted by an authorized testing institute showed that the radiation dose measurement range was 30 𝜇Sv/h ~ 10 mSv/h, so the results are the same as the highest level among products sold commercially at domestic and foreign. In addition, it was confirmed that the measurement uncertainty of ±7.4% was measured, and normal operation was performed under the international standard ±15%.

Two-Dimensional Short Range FMCW Radar Using Dual Transceiver Modules (2중 송수신 모듈을 이용한 2차원 근거리 FMCW 레이다)

  • Seo, Won-Gu;Kim, Dong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.6
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    • pp.531-538
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    • 2016
  • In this paper, we design and fabricate a short range FMCW radar which detects and tracks a moving target in a two-dimensional domain using dual transceiver modules. For the short range radar, we propose a scheme for alternate extraction of the two-dimensional positions using one-dimensional range information from time division transceiver modules, and successfully apply the scheme to the two-dimensional short range radar. Measured results of the targets at 10 m and 30 m are presented as performance demonstration of each transceiver module. Also the performance of the two-dimensional radar is demonstrated using a two-dimensional target map, which uses the range bin corresponding to the frequency resolution, and the effectiveness of the proposed scheme is validated.

Design of 5.5 GHz Band Oscillator for local wireless Communication system (근거리 무선통신용 5.5 GHz 대역 발진기 설계)

  • 김갑기
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.4
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    • pp.787-792
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    • 2004
  • This paper shows the design, fabrication and performance of oscillator appled to 5.5GHz RF module for local wireless communication system. Super low noise HJ FET of NE3210S01 is used to obtain a good phase noise Performance. The design Parameters for the optimum operating performance are simulated with ADS simulation. The measured out Power is 10 dBm at 5.5GHz, the second harmonic suppression -31 dBc, and the phase noise characteristics -98.83 dBc at 100kHz offset frequency, respectively. This implemented oscillator is available to local wireless Communication system.

Design and Fabrication of 5.5 GHz Band Oscillator for local wireless Communication system (근거리 무선통신용 5.5 GHz 대역 발진기 설계 및 제작)

  • 주성남;박청룡;부종배;이영수;김갑기
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.96-100
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    • 2004
  • This paper shows the design, fabrication and performance of oscillator appled to 5.5GHz RF module for local wireless communication system. Super low noise HJ FET of NE3210S01 is used to obtain a good phase noise Performance. The design Parameters for the optimum operating performance are simulated with ADS simulation. The measured out Power is 10 ㏈m at 5.5GHz, the second harmonic suppression -31 ㏈c, and the phase noise characteristics -98.83 ㏈c at 100KHz offset frequency, respectively. This implemented oscillator is available to local wireless Communication system.

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복사성 잡음원의 좌표탐지

  • 임계재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.1
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    • pp.26-30
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    • 2002
  • 실내 및 근거리에서 이용될 수 있는 무선통신의 보호를 위해, 주변 전자파환경의 상황을 일반적인 CISPR 측정 시스템을 이용하여 복사성 잡음원의 위치와 진폭을 탐지하는 방법과 알고리즘을 소개하고, 여기서 탐지된 잡음원의 위치와 진폭에 대한 탐지 정밀도에 대해 분석함으로써 보다 신뢰성 있는 EMC 설계에 이용할 수 있을 것이다.