• Journal of Advanced Marine Engineering and Technology
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• v.32 no.1
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• pp.184-191
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• 2008

In order for a mobile robot to move under unknown or uncertain environment, it must have an environmental information. In collecting environmental information, the mobile robot can use various sensors. In case of using ultrasonic sensors to collect an environmental information, it is able to comprise a low-cost environmental recognition system compared with using other sensors such as vision and laser range-finder. This paper proposes a map building algorithm which can collect environmental information using ultrasonic sensors. And also this paper suggests a traveling algorithm using environmental information which leads to the map building algorithm. In order to accomplish the proposed traveling algorithm, this paper additionally discusses a position revision algorithm.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.22-27
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• 2009

Retinopathy of prematurity (ROP) is a major cause of blindness that affects premature infants. With advances in neonatology, ROP is likely to emerge as the most serious problem of vision loss in children even in developed countries; such a situation could be called the third epidemic of ROP. However, controversy and uncertainty still surround favorable outcomes of ROP. For successfully controlling ROP, timely and accurate screening is crucial because early treatment leads to favorable outcomes. Standard guidelines, including ROP classification, have provided satisfactory instructions for the screening and treatment of ROP. To improve the structural and functional outcomes of ROP, optimizing the timing of surgical interventions including cryotherapy, laser-photocoagulation, encircling, and vitrectomy is essential; these interventions can prevent the sequelae of ROP. It is essential for the neonatologist and the ophthalmologist to cooperate extensively for the successful treatment of ROP.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.82-87
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• 1998

Laser printer, faximile and copy machine are a few examples of OA(office automation) system. In such a system, the reflecting mirror has been employed for transmitting a target image to optical device. Therefore, to develope a good quality of optical system, the quality control of optical mirror was required. In recent years, considerable efforts have been directed toward the development of automated optical glass inspection system because the inspection is eye-fatigue and monotonous job for humans to perform. In this paper, we propose a inspection system applying algorithm of image processing for detecting defects of optical glass such as pinhole, scratch. From the experiments, the proposed inspection system shows reliable results.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.824-828
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• 2007

With increasing interest in the reduction of cost for operation and maintenance of overhead catenary system, various methods of condition monitoring have been developed and used in with high-speed analysis and advanced image processing techniques. This study utilizes a high-speed camera as inspecting system to measure the wear, stagger, hight and arc extinguishing test of overhead catenary system. All measuring image were captured by a high speed CMOS camera with PCI express output, which can acquire up to 1000 frames per second with the resolution 1024 × 1280 pixels. Line type laser source with a power equal to 300 mW and the National Instrument LabVIEW (8.0) based on vision acquisition software have been used in application programming interface for image acquisition, display, and storage. The proposed high-speed camera system is finally applied to measure the overhead catenary system showing promising on-field applications

• 한국가시화정보학회:학술대회논문집
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• 2001.12a
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• pp.6-13
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• 2001

A new GA-3D-PTV technique has been constructed to measure an impinging jet. The measurement system consists of three CCD cameras, Ar-ion laser, an image grabber and a host computer. GA (Genetic Algorithm) was used based on one-to-one correspondences in order to take advantage of the combinatorial optimization in tracking the pairs of the whole particles of the two images having a time interval. Two fitness functions were introduced in order to enhance the correspondences of the particles. One was based on a concept of the continuum theory and the other one was based on a minimum distance error. The constructed GA-3D-PTV system was applied in success to the measurement of flow characteristics of the impinging jet.

• International Journal of CAD/CAM
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• v.9 no.1
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• pp.31-36
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• 2010

3D point data acquired from laser scan or stereo vision can be quite noisy. A preprocessing step is often needed before a surface reconstruction algorithm can be applied. In this paper, we propose a nonparametric approach for noisy point data preprocessing. In particular, we proposed an anisotropic kernel based nonparametric density estimation method for outlier removal, and a hill-climbing line search approach for projecting data points onto the real surface boundary. Our approach is simple, robust and efficient. We demonstrate our method on both real and synthetic point datasets.

• Korean Journal of Computational Design and Engineering
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• v.14 no.1
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• pp.10-17
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• 2009

Surface detection and parameter estimation in point cloud is a relevant subject in CAD/CAM, reverse engineering, computer vision, coordinate metrology and digital factory. In this paper we present a software for a fully automatic surface detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting, which work interactively. Our newly developed algorithms for orthogonal distance fitting(ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. We demonstrate the performance of the software on a variety of point clouds generated by laser radar, computer tomography, and stripe-projection method.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1483-1487
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• 2006

In electric railway, image monitoring using high speed camera provides reliable, timely information of wear and geometry status, important in taking decisions for overhead contact wire maintenance. The contribution of this research is the development of a simple real-time monitoring system for use in measurement subsystem of contact wire and geometry of overhead contact wire in electric railway. The system has been consists of a high speed CMOS camera with resolution $1024{\times}1280$ pixels, line type laser source and PC-based image acquisition system with PCI Express slot. Vision acquisition software have been used in application programming interface for image acquisition, display, and storage with a frequency of sampling of 500 acquisitions per second.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.207-210
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• 2006

자동차 추돌 방지용 레이더는 도로 사정이나 기후에 따른 운전자의 인지 및 판단이 불가능한 상황에서도 차량 간의 추돌을 예방할 수 있는 시스템이다. 현재까지 연구 개발된 차량용 레이더는 초음파나 밀리미터 웨이브 등을 이용하므로 가격이나 크기 등에서 경쟁력을 갖추지 못하고 있는 실정이다. 따라서 본 논문에서는 적외선 레이저 다이오드를 매트릭스 형태로 배열한 다중 파장 구조 방식을 제안하였다. 이는 악천후에서의 탐지 능력을 개선시킬 수 있다. 또한 의사 잡음 수열의 상관 특성을 이용하여 인접 차량의 레이저 신호에 의한 간섭 영향을 최소화시킬 수 있기 때문에 차세대 ITS 기술 선점 및 산업 경쟁력을 확보 등의 효과를 기대할 수 있다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2465-2467
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• 2003

최근 광섬유와 일반 통신 선로 사이의 인터페이스인 레이저 펌프(laser pump)와 같은 광 부품의 수요가 늘어나고 있다. 그러나 대부분의 광 부품 조립은 수작업으로 이루어지고 있기 때문에 한명의 전문가가 하루에 조립할 수 있는 광 부품의 수는 많지 않다. 따라서 이러한 광 부품의 대량생산을 위해서는 광 부픔 제작 과정의 자동화가 이루어져야 한다. 본 논문에서는 980nm 레이저 펌프 조립 과정에서 광섬유 끝단 렌즈의 각도 조절을 자동화하기 위한 비젼 기반의 앵글 튜닝 알고리듬을 제안한다. 제안된 알고리듬은 입력된 영상으로부터 광섬유 끝단 렌즈의 하단 영역의 넓이를 이용하여 광섬유의 각도를 측정하고, 광섬유를 회전시키면서 변화하는 각도 값을 이용하여 광섬유를 원하는 각도로 튜닝 한다.