• 대한기계학회논문집B
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• 제27권6호
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• pp.736-743
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• 2003

A process of 3-D particle image velocimetry, called here, as '3-D stereo PIV' was developed for the measurement of an illuminated slied section field of 3-D complex flows. The present method includes modeling of camera by a calibrator based on the homogeneous coordinate system, transfromation of the oblique-angled image to the right-angled image, identification of 2-D velocity vectors by 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterior, and finally 3-D animation as the post processing. An experimental system was also used for the application of the proposed method. Three analog CCD cameras and an Argon-Ion Laser(300mW) for illumination were adopted to capture the wake flow behind a bluff obstacle.

• Journal of Welding and Joining
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• 제17권3호
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• pp.71-78
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• 1999

The welded metal bellows is commonly manufactured by welding pairs of washer-shaped discs of thin sheet metal stamped from strip stock in thickness from 0.025 to 0.254 mm. The discs, or diaphragms, are formed with mating circumferential corrugations. In this study, the diaphragms were welded by using a CW Nd: YAG laser to form metal bellows. The bellows was fixed on a jig and compressed axially, while Cu-rings were installed between belows edges for intimate contact of edges. The difference between the inner diameter of bellows and jig shaft causes an eccentricity, while the tolerance between motor shaft and jig shaft causes a wobble type motion. A vision sensor which is based on the optical triangulation was used for seam tracking. An image processing algorithm which can distinguish the image by bellows edge from that by Cu-ring was developed. The geometric relationship which describes the eccentricity and wobble type motion was modeled. The seam tracking using the image processing algorithm and the geometric modeling was performed successfully.

• 복식문화연구
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• 제17권2호
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• pp.283-295
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• 2009

This research covers the ways in which typography, which has been expressed in a diverse range of fields and changed communication functions from the era of reading to the era of feeling according to the change in the times and social demands, has been represented in modem fashion, along with examining its inherent aesthetic characteristics. I reviewed the general information of typography's fundamental notions and functions through documented records, and analyzed the inherent aesthetic characteristics by examining the typographical patterns shown in modem fashion based on art works in domestic and international collections after 2000. The result of this research is that typography in modem fashion has been used for improving brand image, expressing social slogans, expressing images, linguistic function for playful expression and the interdependent relationships of modeling functions. Typography in modem fashion has always been diversely expressed harmoniously with linguistic and modeling functions. Through this, the aesthetic characteristics were firstly parodies through direct sentences addressing political and social ideologies, economic gaps, environmental issues and anti-war protests. Secondly, by using brand logos, typography was used as a commercial means like brand-image transfer and separation through customization of other brands. Thirdly, the aesthetic and artistic value of fashion were expressed after being used as experimental visual components like image, motive and patterns which are all elements of fashion design. Fourthly, by distortion and transformation of characters or childish decorations, along with the harmonization of words, cathartic humor was provided for the calloused senses of modern people.

• 패션비즈니스
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• 제8권6호
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• pp.68-77
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• 2004

Hollow filament yarns provide better warmth to the touch, lighter in weight, increased opacity, and subtle luster compared to the regular synthetic filament yarns. However, luster properties of textile fibers or fabrics are often difficult to characterize, partly due to the fineness of the surface texture, the anisotropic nature of the weave structure, the complexity of the fiber array comprising a yarn, and the fiber structure itself. In this study, the fabric surface luster image was analyzed using image analysis methods after image acquisition. The hollow filament fiber was modeled using a three-dimensional modeling software. It was then ray-traced for comparing the virtual luster images of the hollow fiber and the regular fiber models based on shading models including photon mapping. The luster object size of the actual hollow filament fabric was smaller than that of the regular filament fabric. The shape of the luster object of the hollow filament fabric was dual peak type while that of the regular filament was single.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2002년도 추계학술대회 논문집
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• pp.19-22
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• 2002

A process of 3-D particle image velocimetry, called here, as '3-D stereo PIV' was developed for the measurement of a section field of 3-D complex flows. The present method includes modeling of camera by a calibrator based on the homogeneous coordinate system, transfromation of oblique-angled image to transformed image, identification of 2-D velocity vectors by 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system and finally 3-D animation as the post processing. In principle, as two frame images only are necessary for the single instantaneous analysis of a section field of 3-D flow, more effective vectors are obtainable contrary to the previous multi-frame vector algorithm. An experimental system was also used for the application of the proposed method. Three analog CCD cameras and an Argon-Ion Laser(300mW) for illumination were adopted to capture the wake flow behind a bluff obstacle.

• Human Ecology Research
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• 제58권2호
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• pp.163-176
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• 2020

Longitudinal studies have shown mixed findings on the association between body image dissatisfaction and self-esteem among adolescents. This study examined the longitudinal, reciprocal influences between body image dissatisfaction and self-esteem among Korean pre- and early adolescents by using nationally representative longitudinal panel data from the Korean Youth Panel Study (KYPS). Analyses based on 2,230 participants indicated that girls' body image dissatisfaction was significantly higher than boys'. The trajectory of body image dissatisfaction increased sharply during pre- and early adolescence, but stabilized afterwards for both boys and girls. Self-esteem deteriorated rapidly initially, but began to recover as adolescent girls and boys matured. Structural equation modeling showed that reciprocal influences between body image dissatisfaction and self-esteem were detected for boys. Body image dissatisfaction among girls predicted self-esteem during the entire period, while the opposite direction from self-esteem to body image dissatisfaction emerged two years later. The present study found that, during pre- and early adolescence, body image dissatisfaction and self-esteem develop in a circular fashion by forming a vicious cycle. Implications for the development of intervention and prevention programs are discussed in consideration of age and gender.

• 대한원격탐사학회지
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• 제37권6_1호
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• pp.1527-1543
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• 2021

본 논문에서는 포인트 클라우드 데이터를 기반으로 자동으로 군집형 솔리드 건물 모델을 생성하는 기술을 다양한 데이터에 적용, 실험을 수행하여 적용 가능성과 효용성을 탐색한다. 또한 자동 건물 모델링 기술의 한계로 인해 부족한 모델의 품질을 향상시키기 위하여 건물의 형상 편집 및 텍스처 조정 기술을 개발, 실험을 통해 결과를 확인하였다. 자동 건물 모델 생성 기술의 적용 가능성 탐색을 위하여 무인항공기 영상 기반으로 생성된 포인트 클라우드와 LiDAR(Light Detection and Ranging) 자료를 사용해 실험하였으며, 자동으로 생성된 건물 모델에 건물 형상 편집 및 텍스처 조정 기술을 적용하여 모델의 품질의 향상 실험을 수행하였다. 이를 통해 포인트 클라우드 데이터 기반의 자동 군집형 솔리드 건물 모델링 기술의 적용 가능성과 모델의 품질 향상기술의 효용성을 확인하였다. 개발된 기술은 기존의 건물 모델링 기술과 비교하여 처리시간의 비용이 크게 감소하며, 잦은 모델 갱신이 필요한 지역에 대한 관리 측면에서도 강점이 있을 것으로 기대된다.

• 대한원격탐사학회지
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• 제22권3호
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• pp.221-228
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• 2006

In this study, an integrated 3D modeling and rendering system dealing with 3D urban landscape features such as terrain, building, road and user-defined geometric ones was designed and implemented using $OPENGL\;{|}\;ES$ (Embedded System) API for mobile devices of PDA. In this system, the authoring functions are composed of several parts handling urban landscape features: vertex-based geometry modeling, editing and manipulating 3D landscape objects, generating geometrically complex type features with attributes for 3D objects, and texture mapping of complex types using image library. It is a kind of feature-based system, linked with 3D geo-based spatial feature attributes. As for the rendering process, some functions are provided: optimizing of integrated multiple 3D landscape objects, and rendering of texture-mapped 3D landscape objects. By the active-synchronized process among desktop system, OPENGL-based 3D visualization system, and mobile system, it is possible to transfer and disseminate 3D feature models through both systems. In this mobile 3D urban processing system, the main graphical user interface and core components is implemented under EVC 4.0 MFC and tested at PDA running on windows mobile and Pocket Pc. It is expected that the mobile 3D geo-spatial information systems supporting registration, modeling, and rendering functions can be effectively utilized for real time 3D urban planning and 3D mobile mapping on the site.

• 로봇학회논문지
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• 제19권2호
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• pp.188-195
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• 2024

This paper proposes a photorealistic real-time dense 3D mapping system that utilizes a neural network-based image enhancement method and mesh-based map representation. Due to the characteristics of the underwater environment, where problems such as hazing and low contrast occur, it is hard to apply conventional simultaneous localization and mapping (SLAM) methods. At the same time, the behavior of Autonomous Underwater Vehicle (AUV) is computationally constrained. In this paper, we utilize a neural network-based image enhancement method to improve pose estimation and mapping quality and apply a sliding window-based mesh expansion method to enable lightweight, fast, and photorealistic mapping. To validate our results, we utilize real-world and indoor synthetic datasets. We performed qualitative validation with the real-world dataset and quantitative validation by modeling images from the indoor synthetic dataset as underwater scenes.

• 대한전자공학회논문지SP
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• 제43권6호
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• pp.46-56
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• 2006

본 논문에서는 라이팅 환경을 구성하고 있는 광원과 물체의 광학적인 특성을 모델링하여 특정 위치의 관찰자의 시야에 들어오는 3차원 영상을 추정하는 알고리즘을 제안한다. 이전의 논문에서 제안했던 기법을 개선하고, 실제의 자동차 리어램프를 실험에 적용하여 추정한 빛자극과 측정된 빛자극을 비교하여 검증하였다. 랜더링 알고리즘으로는 컴퓨터 그래픽에서 많이 사용되고 있는 광선추적기법을 이용하고, 정확한 실사영상(realistic image)을 재현하기 위하여 물체의 물리적 특성을 반영하는 분광분포를 고려하였다. 물체의 빛 표면반사 및 투과특성과 광원의 빛방출 기하특성을 모델링하여 시점으로 들어오는 빛에너지 추정의 정확도를 개선하였다. 또한 추정된 빛에너지를 인간시각이 느끼는 동일한 색자극으로 디스플레이에 표시할 수 있도록 모니터특성화기법을 적용하여 실사영상에 근접한 영상을 재현하였다.