• 한국멀티미디어학회논문지
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• 제7권3호
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• pp.427-437
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• 2004

3차원 모델간의 형상을 비교하는 것은 형상을 기반으로 하는 인식, 검색, 분류 등을 위해 매우 중요하다. 본 논문에서는 모델의 이동, 회전, 스케일 변화에 영향받지 않고, 모델을 구성하는 정점들이 비균일 하고 불완전한 경우에도 강인한 3차원 형상 비교 방법을 제안한다. 먼저 입력 데이터로부터 고유 모드를 이용한 모달 모델을 구성하고 모달 스트레인 에너지를 이용하여 형상 간의 유사성을 비교한다. 제안된 방법은 고유 진동수에 따라 고유 모드들을 순서화 함으로써 형태 변형을 전역적인 것에서부터 지역적인 것으로 체계화한다. 이렇게 체계화된 형상 표현과 모달 스트레인 에너지를 이용함으로써 국부적인 형태에 치우치지 않고 전체적인 형태의 유사성을 평가하였다.

• 정보처리학회논문지B
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• 제18B권1호
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• pp.21-28
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• 2011

얼굴의 3차원 정보는 얼굴 인식이나 얼굴 합성, Human Computer Interaction (HCI) 등 다양한 분야에서 유용하게 이용될 수 있다. 그러나 일반적으로 3차원 정보는 3D 스캐너와 같은 고가의 장비를 이용하여 획득되기 때문에 얼굴의 3차원 정보를 얻기 위해서는 많은 비용이 요구된다. 본 논문에서는 일반적으로 손쉽게 얻을 수 있는 2차원의 얼굴 영상 시퀀스로부터 효과적으로 3차월 얼굴 형태를 추적하고 재구성하기 위한 3차원 Active Appearance Model (3D-AAM) 방법을 제안한다. 얼굴의 3차원 변화 정보를 추정하기 위해 학습 영상은 정면 얼굴 포즈로 다양한 얼굴 표정 변화를 포함한 영상과 표정 변화를 갖지 않으면서 서로 크게 다른 얼굴 포즈를 갖는 영상으로 구성한다. 입력 영상의 3차원 얼굴 변화를 추정하기 위해 먼저 서로 다른 포즈를 갖는 학습 영상으로부터 얼굴의 각 특징점(Land-mark)의 기하학적 변화를 이용하여 깊이 정보를 추정하고 추정된 특징점의 깊이 정보를 입력 영상의 2차원 얼굴 변화에 추가하여 최종적으로 입력 얼굴의 3차원 변화를 추정한다. 본 논문에서 제안된 방법은 얼굴의 다양한 표정 변화와 함께 3차원의 얼굴 포즈 변화를 포함한 실험 영상을 이용하여 기존의 AAM에 비해 효과적이면서 빠르게 입력 얼굴을 추적(Fitting)할 수 있으며 입력 영상의 정확한 3차원 얼굴 형태를 생성할 수 있음을 보였다.

• 전자공학회논문지SC
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• 제49권4호
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• pp.1-9
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• 2012

본 논문은 금속이나 유리와 같이 정반사 특성을 갖는 경면반사체의 3차원 형상 추정을 위한 영상처리에 관한 것으로, 조명계와 CCD 카메라 및 경면반사체로 이루어진 머신비전 시스템의 기하학적 광로분석을 통해 반사체의 형상이 반사광의 광로에 주는 영향을 수식화하고, 이를 반사체의 3차원 형상 추정에 이용하였다. 즉, 공간적으로 분포된 점광원들이 반사체에 정반사되어 취득된 영상에서, 반사체의 형상에 따라 영상에서의 점광원의 상대적 위치가 변화되므로, 이 변화량을 이용하여 3차원 정보를 추정하는 방법을 제시하고, 실험을 통하여 반사체의 3차원 형상의 추정이 가능함을 보인다.

• Journal of information and communication convergence engineering
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• 제19권2호
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• pp.73-78
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• 2021

As interest in beauty has increased, various studies have been conducted, and related companies have considered the anthropometric data handled between humans and interfaces as an important factor. However, owing to the nature of 3D human body scanners used to extract anthropometric data, it is difficult to accurately analyze a user's body shape until a service is provided because the user only scans and extracts data. To solve this problem, the body shape of several users was analyzed, and the collected anthropometric data were obtained using a 3D human body scanner. After processing the extracted data and the anthropometric data, a custom deep learning model was designed, the designed model was learned, and the user's body shape information was predicted to provide a service suitable for the body shape. Through this approach, it is expected that the user's body shape information can be predicted using a 3D human body scanner, based upon which a beauty service can be provide.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.211-215
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• 2006

This paper presents a new structure for the universal motor using soft magnetic composite (SMC). The stator for this new type of motor is made by combination of the SMC pole and the silicon steel yoke. The shape of the 3D SMC pole is designed to minimize ohmic loss and amount of stator coil. To design the pole shape, the 3D analysis in the design procedure is replaced with an equivalent 2D analysis. Finally, the optimal shape is analyzed by 3D FEM and the performance is discussed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.859-861
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• 2003

In order to present a space in details, it is indispensable to acquire 3D shape and texture simultaneously from the same platform. 3D shape is acquired by Laser Scanner as point cloud data, and texture is acquired by CCD sensor. Positioning data is acquired by IMU (Inertial Measurement Unit). All the sensors and equipments are assembled on a hand-trolley. In this research, a method of integrating the 3D shape and texture for automated construction of Digital Surface Model is developed. This Digital Surface Model is applied for efficient feature extraction. More detailed extraction is possible , because 3D Digital Surface Model has both 3D shape and texture information.

• 동력기계공학회지
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• 제18권6호
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• pp.91-98
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• 2014

The purpose of this research is to investigate optimum machining conditions to improve the quality of die using the CAD/CAM system(Power Shape/Power Mill) and 3D printing. Surface roughness is widely used as an index for processing degree of accuracy. The Power Shape was used to model the shape of product. And the model shape is confirmed by 3D printing system(BFB-3000). Also, tool path and NC-codes were generated using Power Mill. Finally, the product was cut using CNC machine(NBS-2025). The cutting time and surface roughness were measured by measuring instrument. And then this process was repeated by changing the conditions to find optimal machining conditions. The surface roughness behavior with regard to specific factors were analyzed. Through this study, the optimal machining condition can be obtained.

• International Journal of Precision Engineering and Manufacturing
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• 제9권4호
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• pp.16-21
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• 2008

The demand for three-dimensional (3D) shape measurements is increasing in a variety of fields, including the manufacture of molds and dies. The most popular technology for 3D shape measurement is the coordinate measuring machine (CMM) with a contact trigger probe. Although a CMM provides a high degree of accuracy, it is inefficient due to its long measuring time. It also has difficulty measuring soft objects that can be deformed by the touch of the contact probe. In addition, a CMM cannot digitize areas that are difficult to reach, and cannot capture very minute details on the surface of complex parts. For these reasons, optical non-contact measurement techniques are receiving more attention since they eliminate most of the problems associated with contact methods. Laser scanning is emerging as one of the more promising non-contact measurement techniques. This paper describes various acquisition considerations for laser scanning, including the accuracy of the 3D scan data, which depends on the charge-coupled device (CCD) gain and noise. The CCD gain and noise of a 3D laser scanner are varied while keeping the other conditions constant, and the measurement results are compared to the dimensions of a standard model. The experimental results show that a considerable time savings and an optimum degree of accuracy are possible by selecting the proper CCD gain and noise.

• 한국CDE학회논문집
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• 제21권3호
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• pp.306-312
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• 2016

In general, the shape of a 3D printed object is not to be changed after the generation. Most changes, for example, contraction of a molten polymer after cooling is thought to be undesirable. 4D printing however tries to make benefit of a shape change after the part is generated. The shape change is required to be controllable in response to an external stimuli. These artifacts from 4D printing are called kinetic components which are defined as structures formed by combining inert materials and smart materials that change under certain stimuli. We propose a design software that can systematically calculate inert links with smart joints to follow the shape of the target design.

• 패션비즈니스
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• 제21권5호
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• pp.136-150
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• 2017

3D printing has grown tremendously as the most noteworthy new technology in the manufacturing industries. In addition, the rapid development of computer science technology with 3D printing has created a new paradigm called Fractal Geometry, or a new form of digital art. This study explores the formative characteristics of 3D printing jewelry based on presentation of fractal geometry by classification of 3D printing jewelry's morphological types that except for producible shape with traditional mold manufacturing methods. The results of the study are as follows. The morphological characteristics of 3D printed jewelry are divided into their constitutive shapes by the repetition of the unit. The organic shape determined by superposition or overlapping, the systematic shape by distortion caused by distortion, and the variation in scaling by scaling. The formative characteristics, which are drawn from a study on the shape expression of 3D printed jewelry design using fractal geometry, consist of continuity, geometrical characteristics, and exaggeration. Continuity creates a new and self-assigned new space through a recursive structure through a cyclic structure that is formed along a single directional basis. The geometry of the geometry forms a three-dimensional and constructive structure comprised of the same size and structure of the same sized unit under the mathematical order of the geometry of Fractal's geometry. Exaggeration demonstrates the informal beauty and the maximization of the shape by expanding the scaling or superposition of a unit, by scaling the scale or he distortion of the units.