• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.539-539
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• 2000

This paper shows how to implement force reflection for a needle insertion problem. The target is a needle spine biopsy simulator for tumor inspection by needle insertion. Simulated force is calculated from the relationship of volume graphic data and the orientation and Position of the needle, and it is generated using PHANTOM$^{TM}$. To generate realistic force reflection, the directional force of the needle has been generated by tissue model. The other rotational force is generated using a pivot to keep the needle in the initial inserted direction after puncturing the skin. Since the used haptic device has limitation for generating high stiffness and large damping, scale downed model and digital filter are used to stabilize the system.m.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.943-950
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• 2008

A novel nondestructive testing (NDT) system, which is able to detect a crack with high speed and high spatial resolution, is urgently required for inspecting small cracks on express train wheels. This paper proposes a high speed scan type magnetic camera, which uses the multiple amplifying circuits and the crack indicating pulse output system. The linearly integrated Hall sensors are arrayed in parallel, and the Hall voltages from each sensor in the scanning direction are obtained and amplified. High-speed NDT can be achieved by using the exclusive analog-digital converter and micro-processor because the ${\partial}\;V_H/\;{\partial}$ x value, which provides the most important crack information, can be obtained by buffering and calculating. The effectiveness of the novel method was verified by examine using cracks on the wheel specimen model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.164-168
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• 2003

Digital 방사선투과검사 시스템인 1차원 Radiometric scanning system을 개발하여 부식 및 침적물이 있는 배관의 두께평가에 적용하였다. 단일 방사성 동위원소에서 나오는 방사선을 선현으로 접속하여 시험체를 투과시킨 방사선을 BGO 검출기를 사용하여 측정하는 single source - single detector alignment system과 제어 프로그램을 개발하였다. 개발된 시스템의 성능을 GEANT4 프로그램을 사용하여 예측하였다. 그리고, 인공결함을 제작하여 넣은 시편과 두께 변화를 준 시편에 적용하여 실제 성능을 평가하였다. 방사성 동위원소를 이용하여 배관의 부식과 침적물에 의한 두께 변화에 대하여 실시간으로 필름을 사용하지 않고 평가할 수 있음을 확인하였다.

• Korean Journal of Computational Design and Engineering
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• v.16 no.2
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• pp.126-136
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• 2011

The existing approaches to freeform building construction cause many problems. However, recent BIM technique development based on parametric modeling method and improvement of freeform materials manufacturing technology using IT technology encouraged many advanced countries to try experimental projects. Thus, laser scanning technique is in the limelight as a new alternative in the field of freeform building construction and inspection. This study selected a domestic small freeform building and practiced laser scanning and as-planned modeling by using Reverse Engineering. Then each deviation was comparatively analyzed through figures which extracted data by numerically analyzing the newly modeled as-built and Excel spread sheet. Through the process, limits and follow-up research subjects are discussed as well.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.427-433
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• 2008

수치지도는 제작 과정뿐만 아니라 갱신 및 검수 작업도 정확성과 최신성을 유지하기 위해 매우 중요하다. 하지만 항공사진과 현지측량을 통한 기존의 갱신 방법은 짧은 주기로 변하는 현실 세계를 충분히 반영하지 못한다는 한계를 갖고 있어 수치지도의 최신성을 유지하기 위한 효율적인 새로운 갱신 방안이 요구된다. 이를 위해 인터넷건축행정시스템(e-AIS)의 건축도면과 건축물대장정보를 이용하면 신축, 개축, 증축 등이 수시로 일어나는 건물에 대해 수치지도의 갱신을 위한 신속하고 효과적인 대안이 될 수 있다. 본 연구에서는 건축도면에서 추출된 공간 정보와 건축물대장에서 취득된 속성 정보를 이용하여 수치지도의 건물 레이어를 갱신하는 방법을 제시하였다.

• Journal of the Korea Society of Computer and Information
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• v.21 no.9
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• pp.45-49
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• 2016

In this study, an image processing algorithm was developed to increase readability of the images of specific parts of a KTX train acquired by using a mobile digital radiographic testing device in a situation where a running train is stopped. The image processing algorithm was realized by using a Visual C++ development tool. The algorithm developed in this study allows to select an interested region in the acquired images when the interested region is suspected to cause a problem, and applies a thinning process based Sobel operators to the selected region. The experimental results show that the readability of defect parts that are not visible to naked eyes was increased through edge detector. Application of the algorithm developed in this study may help to accurately read non-destructive inspection images.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.525-527
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• 2015

We prepare a catalog of the morphological types of 5840 galaxies within z = 0.01. We determine the morphological types by visual inspection using color images from the Sloan Digital Sky Survey (SDSS) DR7. The majority of the sample galaxies are SDSS spectroscopic target galaxies, but we add ~ 900 galaxies whose redshifts are available in the NASA Extra Galactic Database (NED). The fraction of elliptical and lenticular galaxies is ~ 0.06 while spiral galaxies comprise ~ 30% of the sample with a bar fraction of ~ 0.6. About half of sample are dwarf galaxies of which ~ 35% are dwarf elliptical-like galaxies. There is a strong correlation between the morphological types and luminosities of the galaxies, i.e., high luminosities in the early type galaxies and low luminosity in the late type galaxies. The mean luminosity of dwarf elliptical-like galaxies is similar to that of irregular galaxies.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1320-1325
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• 2006

Railway track supports and guides train and it directly affects ride quality and safety. To maintain track quality, regular maintenance activity is essential but it degrades track usage since maintenance activity occupies the track during the work. To achieve maximum track efficiency, track inspection should be performed at commercial running speed. In this paper, we designed and developed high speed rail profile measurement system using laser light sectioning method with line laser generator, digital camera and DSP based image processing system. The measurement system can supports rail profile measurement at the speed of 300 Km/h that can be applied to KTX.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1686-1687
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• 2007

오늘날 각종 분야에서 널리 사용되고 있는 계측 시스템은 계측 기능을 처리하기 위한 모듈들이 기존의 아날로그 방식에서 디지털 방식으로 급속히 변화하고 있으며, 네트워크, 특히 인터넷과의 연결이 용이하도록 Ethernet 기반의 통신 모듈을 탑재하고 있는 추세이다. 본 논문에서는 Ethernet 기반의 네트워크 기능을 가진 계측 시스템뿐만 아니라 외부와의 통신 인터페이스를 가지고 있는 계측시스템에, 계측 시스템의 측정 오차를 평가할 수 있는 검정 모듈을 탑재함으로써 인터넷을 통해 원격지에서 계측 시스템에 대한 검정을 수행할 수 있는 방법을 제안한다. 제안된 방식을 적용하면 계측 시스템에 대한 검정방식을 오프라인에서 온라인으로 전환할 수 있어, 사용자와 제작자 모두 계측 시스템의 검정에 따른 시간과 물류비용을 절감할 수 있을 뿐만 아니라, 특히, 사용자는 보유한 계측 시스템의 검정 작업을 신속하게 처리할 수 있어 측정에 대한 신뢰성을 상시 확보할 수 있는 장점이 있다.

• Structural Monitoring and Maintenance
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• v.9 no.4
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• pp.373-388
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• 2022

A USW based diagnostic procedure is presented for estimating the depth of surface-breaking cracks. The diagnosis is demonstrated on seven lab-scale SFRC beam specimens, which are subjected to the CMOD controlled three-point bending test to create real bending cracks. Then, the recorded multiple ultrasonic signals are examined with the signal processing techniques, including wavelet transform and two-dimensional Fourier transform, to investigate the relationships between the crack depth and two diagnostic indices, namely the attenuation coefficient and dispersion index (DI). Finally, the reliabilities of these indices for depth estimation are verified with the visually measured crack depths as well as the crack features obtained with a digital image processing algorithm. It is found that the DI outperforms the attenuation coefficient in depth estimation, where this index displays good agreement with the visual inspection for 86% of the inspected specimens.