• 동력기계공학회지
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• 제10권1호
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• pp.34-40
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• 2006

The snow melting system by electric heating wires which is adopted in this study is a part of road facilities to keep surface temperature of the road higher than freezing point of water for melting the snow accumulated on it. The system is designed to increase traffic safety and capacity. The electric heating wires are buried under paved road at a certain depth and operated automatically and manually. Design theory, amount of heating, and installation standard vary according to economic situation, weather condition, and installation place where the system applies. It is tried to figure out that the appropriate range of required heat capacity and installation depth and intervals for solving snowdrifts and freezing problems with the minimum electric power consumption. The most important factors to design the system are calculation of heating capacity depending on weather condition and depth and interval of the electric heating wires depending on air condition respectively. The study were performed under the range of the air temperatures($-2^{\circ}C,\;-5^{\circ}C,\;-8^{\circ}C$), the intervals of the electric heating wires(70mm, 100mm, 125mm), and the installation depths(50mm, 70mm, 100mm). The ready made commercial program package was used to verify the experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.35-38
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• 1990

Depths of the vertical cracks in the concrete were determined by the time of flight of the ultrasonic waves. The ultrasonic waves are diffracted at the crack tip, and the arrival time of ultrasonic waves are dependent on the crack depth and speration distance between transmitting and receiving ultrasonic transducers. The vertical cracks with 0.2-2mm width and 10-100mm depth were examined by multi-layered ultrasonic transducers. It was found that the time of flight of ultrasonic waves were proportional to the depth of vertical cracks. The depth of vertical cracks in the range of 20-100mm depth could be determined by the transient time of the diffracted ultrasonic waves

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.706-709
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• 2005

A hybrid focus method with multiple laser slits has been newly proposed and it is based on the integration of DFD and DFF Rough depth information is estimated using DFD equipped with multiple laser slits, and then DFF is applied to only each specific depth range using the depth information resulting from DFD. The proposed hybrid method gives more accurate results than DFD and DFF, and faster measurement than DFF. Its performance has been verified through experiments of calibration blocks with sharp depth discontinuity.

• 한국환경복원기술학회지
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• 제9권1호
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• pp.72-88
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• 2006

The optimal environmental ranges of the establishment phase for the distribution of Zizania latifolia and Typha angustifolia was determined to develop a set of basic data and criteria of planting substrate for the restoration, conservation and management of wetlands. The study was carried at 17 wetlands in the Kyunggi-do and Gyeongsangnam-do region where inland wetlands place intensively in June, 2005. Total 127 quadrats were sets in growing areas of Zizania latifolia and Typha angustifolia. $NO_3-N$, K, Ca, Mg and Na in the water variables and soil texture, LOI (loss on ignition), soil pH and soil conductivity in the soil variables were analyzed. The optimal range of water depth for the distribution of Zizania latifolia was -5~39cm, $NO_3-N$ content of water was <0.01~0.19ppm, K content of water was 0.1~5.9ppm, Ca content of water 0.5~44.9ppm, Mg content of water was 1.2~11.9ppm, Na content of water 3.4~29.9ppm, water conductivity was 48~450${\mu}S$/cm, respectively. The optimal range of LOI for the distribution of Zizania latifolia was 1.7~11.9%, soil conductivity was 25.5~149.9${\mu}S$/cm, respectively. The optimal range of water depth for the distribution of Typha angustifolia was -20~24cm, $NO_3-N$ content of water was <0.01~0.19ppm, K content of water was 0.2~2.9ppm, Ca content of water 0.6~19.9ppm, Mg content of water was 0.2~5.9ppm, Na content of water 3.5~19.9ppm, water conductivity was 96~450${\mu}S$/cm, respectively. The optimal range of LOI for the distribution of Typha angustifolia was 2.4~15.9%, soil conductivity was 17.6~149.9${\mu}S$/cm, respectively. The optimal soil texture were loam, silt loam and sandy loam in both species. The lower water depth (-20~40cm) is appropriate to increase biodiversity in both species dominated community and it is better to maintain water depth of 40~100cm for water purification. Both species appear frequently in the soil with high silt content.

• 보존과학회지
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• 제28권1호
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• pp.87-94
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• 2012

이 연구에서는 해운대 석각을 대상으로 3차원 레이저 스캐닝 시스템을 적용하여 디지털복원 및 표면심도 모델링을 수행하였다. 먼저 석각의 3차원 디지털복원은 광대역 및 정밀 스캐너를 이용하여 점군 데이터를 획득하였고, 정합, 병합, 필터링, 폴리곤 메쉬, 도면화 작업 순으로 진행하였다. 특히 정밀 스캐닝 폴리곤은 광대역 폴리곤에 비해 글자의 필획, 음각깊이 및 선명도 등이 매우 뛰어났다. 표면심도 모델링은 폴리곤 분리, 기준축 설정, 기준점 선정, 등고선도 맵핑 및 폴리곤 병합을 통해 완성하였으며, 사진과 폴리곤 이미지에 비해 글자의 상대적 음각깊이(5~17mm)와 윤곽이 매우 뚜렷하게 나타났다. 광대역 및 정밀 스캐닝을 병합한 디지털복원 기술을 통해 석각의 전체 형태와 미세형상을 신속하고 정확하게 복원하였고, 표면심도 모델링은 육안과 사진으로 불분명했던 부분을 가시적으로 표현해주었다. 앞으로 정기적인 모니터링을 통해 석각의 다양한 손상과 시간에 따른 주변 환경 변화를 수치적으로 분석할 수 있을 것으로 판단된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1597-1600
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• 1997

Most autonomous mobile robots view things only in front of them. As a result they may collide against objects moving from the side or behind. To overcome the problem we have built an Active Omni-directional Range Sensor that can obtain omni-directional depth data by a laser conic plane and a conic mirror. Also we proposed a self-localization algorithm of mobile robot in unknown environment by fusion of Odometer and Active Omn-directional Range Sensor.

• 전자공학회논문지S
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• 제34S권5호
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• pp.66-72
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• 1997

In this paper, we propose a method improving the accuracy of th eregistration coefficients calculated form two range images considering the measurement error. The employed range finder is based on triangulation and the depth measurement error is described with an error covariance matrix, which is based on thesensitivity of the range measurements. Experimental results demonstrate that the registration coefficients obtained with the proposed method are better than the results when the measurment errors are neglected.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.148-149
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• 2005

In this study, among the precision decline main causes of sounding, I suggested the characteristics of sounding data acquired by echo sounder with increasing of turbidity For this, I acquired sounding data by inputting turbidity inducer artificially in artificial water tank. And then achieved regression analysis. Conclusion are as following : Sounding Capabilities can be divided into three ranges according to the turbidity : normal range, critical range and the range where data can not be obtained by an echo sounder

• 한국생산제조학회지
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• 제25권1호
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• pp.83-88
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• 2016

Because of the increasing tool cost for cutting hard-to-cut materials, abrasive water jet (AWJ) milling recently has been regarded as a potential alternative machining method. However, it is difficult to control the depth and width of cut in AWJ milling because they vary depending on many AWJ cutting parameters. On 27 conditions within a limited range of pressure, feed rate, and abrasive flow rate, AWJ cutting was conducted on titanium, and depth profiles were measured with a laser sensor. From the depth profile data, depth and width of cut were acquired at each condition. The relationships between depth and parameters and between width and parameters were derived through regression analysis. The former can provide proper cutting conditions and the latter the proper pick feed necessary to generate a milled surface. It is verified that pressure mostly affects depth, whereas abrasive flow rate mostly affects width.

• 방송공학회논문지
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• 제9권3호
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• pp.185-195
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• 2004

본 논문에서는 정확한 3차원 장면복원을 위한 다중깊이맵 융합기법을 제안한다. 제안한 기법은 수동적 3차원 정보획득 방법인 스테레오 정합기법과 능동적 3차원 정보획득 방법인 깊이정보 카메라로부터 얻어진 다중깊이맵을 융합한다. 전통적인 두 개의 스테레오 영상 간에 변이정보를 추정하는 전통적 스테레오 정합기법은 차폐 영역과 텍스쳐가 적은 영역에서 변이 오차를 많이 발생한다. 또한 깊이정보 카메라를 이용한 깊이맵은 비교적 정확한 깊이정보를 얻을 수 있으나, 잡음이 많이 포함되며, 측정 가능한 깊이의 범위가 제한되어 있다. 따라서 본 논문에서는 이러한 두 기법의 단점을 극복하고, 상호 보완하기 위하여 이 두 기법에 의해 얻어진다. 중깊이맵의 변이 또는 깊이값을 적절하게 선택하기 위한 깊이맵 융합기법을 제안한다. 3-시점 영상으로부터 가운데 시점을 기준으로 좌우 영상에 대해 두 개의 변이맵들을 각각 얻으며, 가운데 시점 카메라에 설치된 깊이정보 카메라로부터 얻어진 깊이맵들 간에 위치와 깊이값을 일치시키기 위한 전처리를 행한 다음. 각 화소 위치의 텍스쳐 정보, 깊이맵 분포 등에 기반하여 적절한 깊이값을 선택한다. 제안한 기법의 컴퓨터 모의실험 결과. 일부 배경 영역에서 깊이맵의 정확도가 개선됨을 볼 수 있었다.