• 대한조선학회논문집
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• 제40권6호
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• pp.58-68
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• 2003

Despite the availability of 3D CAD systems, the designers in shipyards still use 2D CAD systems because of the need to produce drawings rapidly and a shortage of labor. The design information of ship structure contained in 2D drawings is represented by symbols that are well known among designers in shipyard. The shapes of symbols are recognized by analysis of experienced and knowledgeable designers. We propose a method for automatic recognition of 2D symbols and extraction of design information from the midship drawings. The shape and rationale of 20 symbols used in ship design have been analyzed, and symbols have been classified according to the analysis. Based on the classified symbols, the developed system recognizes the symbols expressed in 2D drawings. The meaningless geometric shape is translated into the design information including designer's intents. The extracted design data can be applied to the downstream design process in shipyards, and the 3D ship model can be automatically created.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.171-171
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• 2012

In this study, we fabricated the high-brightness AlGaInP-based red light emitting diodes (LED)s using by direct printing technique and inductive coupled plasma (ICP) reactive ion etching (RIE). In general, surface roughening was fabricated by wet etching process to improve the light extraction efficiency of AlGaInP-based red LED. However, a structure of the surface roughening, which was fabricated by wet etching, was tiled cone-shape after wet etching process due to crystal structure of AlGaInP materials, which was used as top-layer of red LED. This tilted cone-shape of surface roughening can improve the light extraction of LED, but it caused a loss of the light extraction efficiency of LED. So, in this study, we fabricated perfectly cone shaped pattern using direct printing and dry etching process to maximize the light extraction efficiency of LED. Both submicron pattern and micron pattern was formed on the surface of red LED to compare the enhancement effect of light extraction efficiency of LEDs according to the diameter of sapphire patterns.After patterning process using direct printing and ICP-RIE proceeded on the red LED, light output was enhanced up to 10 % than that of red LED with wet etched structure. This enhancement of light extraction of red LED was maintained after packaging process. And as a result of analyze of current-voltage characteristic, there is no electrical degradation of LED.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.61-65
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• 2016

Facial feature detection is a fundamental function in the field of computer vision such as security, bio-metrics, 3D modeling, and face recognition. There are many algorithms for the function, active shape model is one of the most popular local texture models. This paper addresses issues related to face detection, and implements an efficient extraction algorithm for extracting the facial feature points to use on iOS platform. In this paper, we extend the original ASM algorithm to improve its performance by four modifications. First, to detect a face and to initialize the shape model, we apply a face detection API provided from iOS CoreImage framework. Second, we construct a weighted local structure model for landmarks to utilize the edge points of the face contour. Third, we build a modified model definition and fitting more landmarks than the classical ASM. And last, we extend and build two-dimensional profile model for detecting faces within input images. The proposed algorithm is evaluated on experimental test set containing over 500 face images, and found to successfully extract facial feature points, clearly outperforming the original ASM.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.81-86
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• 1987

An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.

• 한국CDE학회논문집
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• 제15권1호
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• pp.33-42
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• 2010

In this study, new medial surface calculation methods using Voronoi diagrams are investigated for the point samples extracted on closed surface models. The medial surface is defined by the closure of all points having more than one closest point on the shape boundary. It is a one of essential geometric information in 3D and can be used in many areas such as 3D shape analysis, dimension reduction, freeform shape deformation, image processing, computer vision, FEM analysis, etc. In industrial parts, the idealized solid parts and shell shapes including sharp edges and vertices are frequently used. Other medial surface extraction methods using Voronoi diagram have inherent separation and branch problems, so that they are not appropriate to the sharp edged objects and have difficulties to be applied to industrial parts. In addition, the branched surfaces on sharp edges in shell shapes should be eliminated to obtain representative medial shapes. In order to avoid separation and branch problems, the new approach by analyzing the shapes and specially sampling on surfaces has been developed.

• 한국정보처리학회논문지
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• 제6권10호
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• pp.2809-2815
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• 1999

Level set, and active contour(snakes) models are extensively used for image segmentation or shape extraction in computer vision. Snakes utilize the energy minimization concepts, and level set is based on the curve evolution in order to extract contours from image data. In general, these two models have their own drawbacks. For instance, snake acts pooly unless it is placed close to the wanted shape boundary, and it has difficult problem when image has multiple objects to be extracted. But, level set method is free of initial curve position problem, and has ability to handle topology of multiple objects. Nevertheless, level set method requires much more calculation time compared to snake model. In this paper, we use good points of two described models and also apply multi resolution algorithm in order to speed up the process without decreasing the performance of the shape extraction.

• 대한원격탐사학회지
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• 제25권2호
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• pp.145-154
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• 2009

고해상도 위성영상이 갖는 공간 객체의 복잡성과 다양성에 의해 기존 중 저해상도 영상에서 사용하던 분류 방식을 고해상도 영상에 그대로 적용하기에는 한계가 있다. 이러한 문제를 극복하기 위하여 영상의 공간적인 특성을 추가적으로 추출하여 분광정보와 결합하여 분류를 수행하는 방식의 연구가 진행되고 있다. 본 연구의 목적은 고해상도 영상의 분류정확도를 개선하기 위하여 새로운 공간 개체(spatial feature)인 SSI(Shape-Size Index)를 제안하는데 있다. SSI feature는 영역 확장(Region Growing) 기반의 영상 분할(Image Segmentation)을 수행한 후, 세그먼트 내에 공간 속성값을 할당하여 공간정보를 추출한다. 추출된 공간정보를 고해상도 영상의 다중분광 밴드와 결합하여 Support Vector Machine(SVM)을 이용한 분류를 수행하였다. SSI를 구성하는데 필요한 두 매개변수인 분할변수와 가중치변수의 최적값을 얻기 위해서 고해상도 위성영상인 KOMFSAT-2와 QuickBird-2에 반복적으로 적용하였다. 결과적으로 고해상도 영상의 공간특성을 표현하는데 적합한 매개변수를 통하여 도출된 SSI와 고해상도 분광 밴드를 결합하여 분류를 수행한 결과가 분광밴드만을 이용하여 분류를 수행한 결과에 비해 높은 분류정확도를 도출함을 확인하였다.

• 한국지능시스템학회논문지
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• 제19권6호
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• pp.834-839
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• 2009

지능로봇시스템과 같은 HCI 환경에서 사람의 감정을 인식하기 위한 매개정보인 얼굴영상 기반 정서특징 검출문제는 관련분야의 매우 중요한 이슈이다. 본 논문에서는 보편화된 시스템 기반에서 임의의 사용자에 대한 정서 인식을 수행하기 위해 사람의 얼굴에서 나타나는 최적의 정서특징을 가장 효율적으로 추출하기 위한 연구로서 본 연구실에서 기존에 제안한 FACS와 AAM을 이용한 Bayesian Network 기반 얼굴표정 인식 시스템을 보완한 Advanced AAM을 기반 얼굴영상 정서 특징을 검출 시스템에 대한 연구를 진행하였다. 이를 수행하기 위하여 정규화된 이미지에서의 Statistical Shape Analysis로서 Advanced AAM과 얼굴 표정 분석 시스템인 FACS를 이용하여, 임의의 사용자에 대한 자동적인 정서특징 검출이 가능하도록 연구를 진행하였다.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.39-44
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• 2022

The light extraction technology for improving the light efficiency of OLEDs is the core technology for extracting the light inside the OLEDs to the outside. This study demonstrates a simple method to generate random nanostructures (RNSs) containing high refractive index nanoparticles to improve light extraction and viewing angle characteristics. A simple dry low-temperature process makes the nanostructured scattering layer on the polymer resin widely used in the industry. The scattering layer has the shape of randomly distributed nanorods. To control optical properties, we focused on changing the shape and density of RNSs and adjusting the concentration of high refractive index nanoparticles. As a result, the film of the present invention exhibits a perpendicular transmittance of 85% at a wavelength of 550 nm. This film was used as a scattering layer to reduce substrate mode loss and improve EL efficiency in OLEDs.

• Current Optics and Photonics
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• 제7권4호
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• pp.387-397
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• 2023

Tooth surface shape error is an important parameter in gear accuracy evaluation. When tooth surface shape error is measured by laser interferometry, the gear interferogram is highly distorted and the gray level distribution is not uniform. Therefore, it is important for gear interferometry to extract the foreground region from the gear interference fringe image directly and accurately. This paper presents an approach for foreground extraction in gear interference images by leveraging the sinusoidal variation characteristics shown by the interference fringes. A gray level mask with an adaptive threshold is established to capture the relevant features, while a local variance evaluation function is employed to analyze the fluctuation state of the interference image and derive a repair mask. By combining these masks, the foreground region is directly extracted. Comparative evaluations using qualitative and quantitative assessment methods are performed to compare the proposed algorithm with both reference results and traditional approaches. The experimental findings reveal a remarkable degree of matching between the algorithm and the reference results. As a result, this method shows great potential for widespread application in the foreground extraction of gear interference images.