• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.100-108
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• 2004

In reverse engineering, data acquisition methodology can generally be categorized into contacting and non-contacting types. Recently, researches on hybrid or sensor fusion of the two types have been increasing. In addition, efficient construction of a geometric model from the measurement data is required, where considerable amount of user interaction to classify and localize regions of interest is inevitable. Our research focuses on the classification of each bounded region into a pre-defined feature shape fer a hybrid measuring scheme, where the overall procedures are described as fellows. Firstly, the physical model is digitized by a non-contacting laser scanner which rapidly provides cloud-of-points data. Secondly, the overall digitized data are approximated to a z-map model. Each bounding curve of a region of interest (featured area) can be 1.aced out based on our previous research. Then each confined area is systematically classified into one of the pre-defined feature types such as floor, wall, strip or volume, followed by a more accurate measuring step via a contacting probe. Assigned to each feature is a specific digitizing path topology which may reflect its own geometric character. The research can play an important role in minimizing user interaction at the stage of digitizing path planning.

• Spatial Information Research
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• v.8 no.1
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• pp.69-83
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• 2000

Cadastral map is the basic data that prescribe a lot number, the classification of land category, a boundary and ownerships of the parcels. Because the analogue cadastral map is not appropriate for the Parcel Based Land Information System, computerization of cadastral map is needed. When considering other automatic vectorizing softwares, we conclude that they can not satisfy the accuracy needed in cadastral map. Also screen digitizing methods demand lots of time. So we developed semi-automatic vectorizing program that realized almost capacities, such as overlay display which is needed for screen digitizing , window link, vector file generation , and so forth. As comparing screen digitizing method using AutoCAD with our developed program, we could obtain not only almost same accuracy , but also 35 minute reduction in vectorizing.

• Korean Journal of Computational Design and Engineering
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• v.2 no.4
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• pp.253-266
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• 1997

Pencil-curve machining, which is a single-pass ball-end milling along a concave edge on adie surface, is widely employed in die-surface machining. The cutter-path used for pencil-curve machining, which is the trajectory of the “ball-center point” of a ball-endmill sliding along a concave-edge region on the die surface, is called pencil-curve. Presented in the paper is a pencil-curve tracing algorithm in which “concave-type” sharp edges are computed from a “virtually digitized” model of the tool-envelope surface. The resulting “initial” pencil-cures are then refuted by applying a series of fairing operations. illustrative examples and methods for enhancing accuracy are also presented. The proposed pencil-curve tracing algorithm has been successfully implemented in a commercial CAM system specialized in die-machining and in the CAD/CAM system CATIA.

• Journal of Korean Society for Quality Management
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• v.29 no.3
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• pp.66-78
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• 2001

This paper deals with problem of determining process target value under automated visual inspection(AVI) system. Three independent error sources - digitizing error, illumination error, and positional error - which have a close relationship with the performance of the AVI system, are considered. Assuming that digitizing error is uniformly or normally distributed and illumination and positional errors are normally distributed, respectively, the distribution function for the error of measured lengths is derived when the length of a product is measured by the AVI system. Then, Optimal target values under two error models of AVI system are obtained by minimizing the total expected cost function which consists of give away, rework and penalty cost. To validate two process setting models, AVI system for drinks filling process is made up and test results are discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.297-306
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• 1992

Algorithms for implementing one chip binary image processor has been studied. In this paper, image quality improvement algorithms, for the data pre-processed with shading and gamma correction after digitizing the analog signal from CCD or CIS, such as : Improved high quality binarization algorithm is suggested. Error diffusion algorithms for high quality half-tone images is analyzed, Fuzzy Theory based mixed mode algorithm is suggested.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.172-179
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• 2002

In this paper, an efficient reverse engineering method for free-formed surfaces is proposed based on the integration of a repetitive digitizing method and vision system. In recent reverse engineering process, the equi-interval digitization method is being used since the surface information is not known. If more accurate results are required, the number of measuring point should be increased appropriately. Thus, such measuring process tends to result in too dense data including useless information, and cause excessive measuring time. This problem can be improved by applying repetitive digitizing method and image process technique, which is proposed in this paper. The proposed methods are validated through appropriate simulation and experiments.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.544-549
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• 2003

본 논문에서는 Head-up Digitizing / Vectorizing 기술에 주로 사용되는 이진 영상으로부터 사용자의 초기 입력 좌표를 기준점으로 채택한 후 기준점을 중심으로 선형 및 벡터 형상을 추출하는 반자동 선형 추출 기술 개발에 관해 기술한다. 본 기술의 동작 과정을 살펴보면 다음과 같다. 사용자는 이진 영상에서 추출하고자 하는 선형 및 벡터 형상내의 한 좌표를 선택한다. 선택된 좌표는 기준점으로 채택되며, 이 기준점을 중심으로 네 방향으로 영암 값이 0인 픽셀들의 길이 및 orientation이 계산된다. 계산된 orientation을 바탕으로 폭 넓이가 계산되고 초기 좌표가 보정된 후 폭 넓이가 임계값을 만족시키면 동일한 선형물로 간주하여 추출 연산을 반복 수행하고, 폭넓이가 임계값을 벗어나면 새로운 선형물로 간주하고 추출을 중단한다 즉, 채택된 기준값을 중심으로 동일한 명암값의 검색을 진행하여 기준값과 유사한 방향성 및 폭 넓이 정보를 갖는 성분들의 중심 좌표를 선형물 추출 결과값으로 산출하는 기술이다. 본 기술을 통해 수작업으로 진행되던 지도 제작 및 Head-up Digitizing / Vectorizing 기술이 컴퓨터를 이용한 반자동기술로 대체될 수 있으며, 이를 통해 많은 인원과 시간을 소모하여야 했던 좌표 지도제작을 위성 영상을 이용하여 보다 쉽고 저렴한 가격으로 수행할 수 있는 방안을 제시할 수 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.10 no.2
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• pp.49-55
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• 1992

Sampling techniques is very important in digital elevation model. There are scanning and digitizing method of sampling techniques. This study is limited in digitizing method. Continous sampling method use contour lines as same entity and grid method is a direct reading of sample elevation in each grid. Triangulated irregular method is needed to identity topographical lines to sample elevation data. As a results, authors know that continous sampling method has economic in input system and triangulated irregular method has a small memory size.

• Korean Journal of Remote Sensing
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• v.12 no.1
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• pp.17-25
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• 1996

This paper presents a GCP marking technique using scanned maps. Twelve maps with a scale of 1:250, 000 were scanned and stored as raster images. The distortion factors of scanned maps were modelled by polynomials. The coefficients of the polynomials were determined by a least squre fit. This technique does not require a bulky and expensive digitizing table so that it is suitable for a low-cost pre-processing system. The GCP marking using this technique showed a sufficient accuracy for KITSAT1, 2 narrow camera images.

• Korean Journal of Anesthesiology
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• v.71 no.6
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• pp.486-487
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• 2018