• Electronics and Telecommunications Trends
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• v.11 no.3 s.41
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• pp.57-70
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• 1996

본 고에서는 IEEE의 표준안테나 방법과 표준전장 방법의 두 가지 전계강도 측정방법을 고찰하였다. 표준 안테나 방법은 측정될 전계에 의해 표준 수신안테나에 형성된 수신전력 또는 개방전압을 측정하고 측정된 전압과 표준안테나의 치수 및 형태로부터 전계강도를 계산하는 방법이다. 표준 전장 방법은 측정될 전장 및 표준 전장에 의해 안테나에 나타나는 전압을 비교하는 방법이다. 표준전장의 크기는 전송안테나의 치수, 전류분포, 이격거리, 대지효과에 의해 계산된다. 범용적인 전계강도의 보정과 마이크로웨이브 주파수까지 확장된 전계강도 측정방법을 포함한 전계강도 측정절차에 관한 사항이 요약되었다.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.158-165
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• 2016

The purpose of this study was to analyze photoplethysmographic waveforms from pulse oximeter using raw data of red and infrared light and investigate the reference values of parameters (Height, Width50, Maximum slope, Minimum slope, Area) for evaluating pulpal blood flow in maxillary central incisors with normal pulp vitality in children. The study was performed in 30 pediatric patients, aged 7-16 years old, using pulse oximeter (MEKICS Co., Ltd, Korea) combined with a custom-made sensor. The raw data was obtained and recorded by custom-made software and analyzed by LabChart (v.7.3, ADInstruments, Germany) offline. In this study, we analyzed photoplethysmographic waveforms from pulse oximeter applied to maxillary central incisor for assessment of pulpal blood flow and suggested several reference values of young permanent maxillary central incisor with normal pulp. On average, the waveform of red light was higher, stiffer and wider than that of infrared light. Future studies about reference values for other normal teeth and the teeth with impaired pulp vitality are needed.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1583-1587
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• 2007

최근 기상변동에 따른 집중호우와 태풍의 영향으로 풍수해 피해지역 및 재산피해액이 증가하고 있다. 그러나 정확한 수위와 유량의 관계를 측정하여 유출특성을 파악하는 기초적인 연구는 예산상의 문제로 다지점에 대해 지속적으로 이루어 지지 못하고 있는 실정이다. 본 연구의 대상유역인 강원도 삼척인근의 오십천 유역은 지난 2002년 루사, 2003년 매미 등 대형 태풍이 지나갈 때 마다 많은 인명과 재산피해를 발생시킨 유역이다. 그러나 지금까지 정확한 유량측정을 통한 수위-유량 관계곡선이 도출되어 있지 않아 합리적인 이수 및 치수계획 수립과 수공구조물의 설계에 많은 어려움을 겪고 있다. 따라서, 본 연구에서는 오십천 유역에 적합한 정확하고 신뢰성 있는 수위-유량 관계곡선을 개발하여 합리적이고 경제적인 이수 및 치수계획 수립과 각종 수공구조물 설계에 필요한 수문량 결정의 기본 자료를 제공하고자 유속계와 부자를 이용하여 정기적으로 유속을 측정하고 수위-유량 관계곡선을 개발하였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.10-20
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• 2018

The aim of this study was to evaluate the factors affecting the healing of root fracture in immature permanent teeth and the prognosis of root fracture by statistically analyzing the relationship with the pulp and root healing. The radiographs of 51 root-fractured maxillary anterior permanent teeth were collected. In radiograph, locations of root fracture, apical foramen width and width of diastasis between the fragments were measured. The value of the studied parameters were compared by independent t-test and rogistic regression test. In conclusion, there was no difference in the prognosis of pulp healing according to the location of root fracture. However, root healing occurs well as the root fracture is located at the root apex (p < 0.05). Lastly, the smaller the width of diastasis between the fragments after reduction, the better the pulp healing was (p < 0.05).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.690-695
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• 2004

A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3-D data of an object was calculated from the 2dimensional image information obtained by the laser stripe using the laser triangulation. The system can measure the diameter of hole not only in a normal plane but also in an incline plane. We can experiment with magnification that is optimized according to size of object using zoom lens. In this paper, the theoretical formula and calibration of the system were described. The measuring precision of the system was investigated by experiment.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.110-117
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• 1997

Alloy 690 제1열 시제 전열관을 U 굽힘 가공할 시 전열관에 도입된 표면 잔류응력 및 굽힘 단면에서 치수변화 (벽두께, 진원도)를 위치별로 측정하여 평가하였다. 외측호(extrados)의 표면 잔류응력은 $\psi$=0$^{\circ}$에서 축 방향 응력이 -319 MPa (압축)로 가장 높았으며, 내측호(intrados)는 $\psi$=0$^{\circ}$, 160$^{\circ}$ 위치인 천이영역 부관에서 응력 변화가 크게 되는 경향을 보였다 측면(flank)은 인장 잔류응력으로 $\psi$=90$^{\circ}$(apex)에서 최대 190 MPa 로 축방향 응력으로 나타났다. 잔류응력치는 벽두께 보다는 진원도 변화와 일치되어 나타났으며, 시제 전열관의 벽두께 및 진원도는 ASTM의 치수 허용치 내에 포함되는 것으로 평가되었다. 잔류응력 측정은 스트레인 게이지를 이용한 구멍뚫기 방법 (Hole-Drilling Method)을 사용하였다.

• Water for future
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• v.32 no.4
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• pp.44-48
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• 1999

• CDE review
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• v.14 no.2
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• pp.37-41
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.32 no.6
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• pp.543-551
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• 2015

In this study, a novel method for dimension measurement of large-scale moving objects using stereo camera with 2-degree of freedom (2-DOF) mechanism is presented. The proposed method utilizes both the advantages of stereo vision technique and the enlarged visibility range of camera due to 2-DOF rotary mechanism in measuring large-scale moving objects. The measurement system employs a stereo camera combined with a 2-DOF rotary mechanism that allows capturing separate corners of the measured object. The measuring algorithm consists of two main stages. First, three-dimensional (3-D) positions of the corners of the measured object are determined based on stereo vision algorithms. Then, using the rotary angles of the 2-DOF mechanism the dimensions of the measured object are calculated via coordinate transformation. The proposed system can measure the dimensions of moving objects with relatively slow and steady speed. We showed that the proposed system guarantees high measuring accuracy with some experiments.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.331-337
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• 2006

Specimens with fillet-welded lap joints were fabricated from 20 mm, 60 mm, and 82 mm thick steel plates produced by Thermo Mechanical Control Process. The designed sizes of filet welds were betwen 6 mm and 16 m. The welds' axes were parallel with or perpendicular to the direction of loading or a combination of them. Specimens were axialy loaded in tension and the strength of fillet-welded joints were measured. Test results showed that the strengths of filet-welded joints are higher than the nominal strengths calculated for all the cases tested, and also approximately on the same level regardless of plate thickness and fillet weld size. Especially, the specimens with weld size les than that required by Korean design rules showed no visible defects on welds and also no str ength reduction.