• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3703-3709
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• 1999

We propose a new approach to reconstruct the surface shape of an object from a shaded image. We use genetic algorithm instead of gradient descent algorithm which is apt to take to local minima and also proposes genetic representation and suitable genetic operators for manipulating 2-D image. And for more effective execution, we suggest hierarchical process to reconstruct minutely the surface of an object after coarse and global reconstruction. A modified Lambertian illumination model including the distance factor was herein adopted to get more reasonable result and an experiment was performed with synthesized and real images to demonstrate the devised method, of which results show the usefulness of our method.

• Journal of Welding and Joining
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• v.5 no.3
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• pp.1-10
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• 1987

용접과정에 필요한 데이타를 신속하게 얻을 수 잇는 용접데이타 시스템(1)을 개발하였다. 용접데이타 시스템은 철강재료의 용접에 적용할 수 있고 관계형 데이타베이스 시스템을 채택하고 있으며 용접 데이타베이스, dBASE 3 PLUS 및 응용 프로그램으로 구성되어 있다. 용접데이타는 용접법, 모재, 용접재료, 이음부 형상, 용접시공 데이타를 수록하고 있으며, 응용프로그램은 데이타의 신규입력, 수정, 삭제, 검색의 4부분으로 구성되어 있고 사용자의 편의를 위해 I/O format program과 graphic 처리를 위한 BASIC 프로그램이 포함되어 있다. 프린터로의 출력은 현장에서 이용 가능한 PQR의 형태를 취하고 있다.

• Computational Structural Engineering
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• v.11 no.4
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• pp.361-370
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• 1998

본 논문에서는 역전파학습에 의한 신경망기법을 사용하여 구조물의 미지계수를 추정하는 기법을 연구하였다. 대형구조물의 경우 계측 또는 추정하여야 하는 자유도의 수가 많으므로 인하여 구조계수를 추정하는 데에는 많은 어려움이 존재한다. 이러한 어려움을 극복하기 위하여 부구조추정법과 부행렬계수를 사용하여 추정하고자 하는 미지계수의 수를 효율적으로 줄일 수 있도록 하였다. 구조물의 고유주파수 및 모드형상 등의 모드계수를 신경망의 입력자료로 사용하였으며, 추정하고자 하는 부재의 부행렬계수를 신경방의 출력자료로 사용하였다. 입력자료로 사용되는 모드계수에 포함되어 있는 계측오차 및 신호처리오차의 영향을 줄이기 위하여, 신경망의 학습과정에서 노이즈를 첨가하는 기법을 사용하였다. 일반적인 형태의 자켓구조물을 대상으로 수치해석을 수행함으로써 제안기법의 대형구조계에 대한 적용성을 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.460-464
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• 2001

Recently, the use of Robot increase little by little for the purpose of developing a welding quality and productivity in the arc welding part. It is more important to contact the seam for arc welding before moving a welding robot. There are two types of method to contact the seam namely contact and noncontact type largely In this paper, image processing sensor(a kind of non-contact sensor) is concerned to track the seam by using laser diode and CCD camera. A structured laser diode's light illuminated on the weld groove and the reflected shape is introduced by CCD camera. The image board captures this image and software analyzes this image. The robot is moved and welded exactly as acquired image X-Y data is changed with robot's X-Y value. Also, most of seam tracking are considered by changing the program simply in case of the different weld prove of plane surface.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.600-611
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• 1996

Recently, neural network-based speech recognition has been studied to utilize the adaptivity and learnability of neural network models. However, conventional neural network models have difficulty in the co-articulation processing and the boundary detection of similar phonmes of the Korean speech. Also, in case of using one phonotopic map, learning speed may dramatically increase and inaccuracies may be caused because homogeneous learning and recognition method should be applied for heterogenous data. Hence, in this paper, a neural net typewriter has been designed using a hierarchical self-organizing classifier(HSOC), and related algorithms are presented. This HSOC, during its learing stage, distributed phoneme data on hierarchically structured multiple phonotopic maps, using Kohonen's self-organizing feature maps(SOFM). Presented and experimented in this paper were the algorithms for deciding the number of maps, map sizes, the selection of phonemes and their placement per map, an approapriate learning and preprocessing method per map. If maps are divided according to a priorlinguistic knowledge, we would have difficulty in acquiring linguistic knowledge and how to alpply it(e.g., processing extended phonemes). Contrarily, our HSOC has an advantage that multiple phonotopic maps suitable for given input data are self-organizable. The resulting three korean phonotopic maps are optimally labelled and have their own optimal preprocessing schemes, and also confirm to the conventional linguistic knowledge.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.325-335
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• 1996

Visual features are crucial for monitoring the growth state, indexing the drying performance, and grading the quality of oak mushrooms. A computer vision system with neural net information processing technique was utilized to quantize quality factors of a dried oak mushrooms distributed over the cap and gill sides. In this paper, visual feature extraction algorithm were integrated with the neural net processing to deal with various fuzzy patterns of mushroom shapes and to compensate the fault sensitiveness of the crisp criteria and heuristic rules derived from the image processing results. The proposed algorithm improved the segmentation of the skin features of each side, the identification of cap and gill surfaces, the identification of stipe states and removal of the stipe, etc. And the visual characteristics of dried oak mushrooms were analyzed and primary visual features essential to tile quality evaluation were extracted and quantized. In this study, black and white gray images were captured and used for the algorithm development.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.819-826
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• 2002

Cellular neural networks(CNN) are neural networks that have locally connected characteristics and real-time image processing. Locally connected characteristics are suitable for VLSI implementation. It also has applications in such areas as image processing and pattern recognition. In this thesis cellular neural networks are used for feature detection in number recognition at the stage of re-processing. The four or six directional shadow detectors are used in numbers recognition. At the stage of classification, this result of feature detection was simulated by using a multi-layer back Propagation neural network. The experiments indicate that the CNN feature detectors capture good features for number recognition tasks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5769-5777
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• 2015

According to the forming or bending deformation in the press die, the thin plate occurs a work-hardening, the sheet hardening and cam unit's deformation causes incomplete forming during the cam molding process by the reacting spring forces. This study treated the input parameters of the stress and strain as given properties and also used Cam forming pressure considering the sheet hardening in the forming process of the aluminum sheet. The Hyperstudy are operated be linked with the Abaqus of the finite element analysis tool and the shape of Cam were carried out with non-linear shape optimization analysis. As a result removing the deformation of plate, the cam shape were optimized under conditions reduced deformation, having a minimum stress range and the minimum deformation. Therefore, a stress-strain curve and a normal distribution of stress-thickness can be obtained and optimization could be obtained for the shape of the stress and strain on the die plate hardened cam considering the thickness and reaction force of gas spring as iteration process.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.869-873
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• 2007

본 논문은 고속으로 생산되는 제품의 영상을 캡쳐한 후 영상처리 기법 중 에지 추출 알고리즘을 응용하여 조명에 투과된 제품의 에지를 추출 및 필터링 하는 방법으로 결함 검출 시스템을 설계한다. 소형의 임베디드 기기에 패턴 매칭 영상처리 기법을 이용하여 결함을 검출하고 패턴의 비 매칭 정도를 기준점에 따라 정상 또는 불량 판정을 할 수 있는 어플리케이션을 개발하고 탑재하였고, 어플리케이션의 불량 판정 알고리즘으로는 NGC (Normalized GrayScale Corelation) 기법을 사용하였고 검출 판정 결과 적절한 판정값을 입력하는 것으로 기준 패턴과 형상이 다른 대상의 불량을 판정한다.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.123-132
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• 1999

This paper describes a research work of developing computer-aided design of lead frame, semiconductor, with blanking operation which is very precise for progressive working. Approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from pasticity theories, experimental results and the empirical knowledge of field experts. This system has been written in AutoLISP on the AutoCAD using a personal computer and in I-DEAS Drafting Programming Language on the I-DEAS Master Series Drafting with Workstation, HP9000/715(64). Transference of data between AutoCAD and I-DEAS Master Series Drafting is accomplished by DXF(drawing exchange format) and IGES(initial graphics exchange specification) methods. This system is composed of five modules, which are input and shape treatment, production feasibility check, strip-layout, data-conversion and die-layout modules. The process planning and Die design system is designed by considering several factors, such as complexities of blank geometry, punch profiles, and the availability of a press equipment and standard parts. This system provides its efficiecy for strip-layout, and die design for lead frame, semiconductor.