• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 봄 학술발표논문집 Vol.31 No.1 (B)
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• pp.715-717
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• 2004

This paper proposes a new reconstruction method of high-resolution facial image from a low-resolution facial image based on a recursive error back-projection of top-down machine learning. A face is represented by a linear combination of prototypes of shape and texture. With the shape and texture information about the pixels in a given low-resolution facial image, we can estimate optimal coefficients for a linear combination of prototypes of shape and those of texture by solving least square minimization. Then high-resolution facial image can be obtained by using the optimal coefficients for linear combination of the high-resolution prototypes, In addition to, a recursive error back-projection is applied to improve the accuracy of synthesized high-resolution facial image. The encouraging results of the proposed method show that our method can be used to improve the performance of the face recognition by applying our method to reconstruct high-resolution facial images from low-resolution one captured at a distance.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.281-286
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• 2005

The goal in facial paralysis treatment is to achieve the normal appearance of the face as well as to reconstruct the natural symmetrical smile. In cases of facial paralysis, a widely accepted procedure is the two stage method, which combines neurovascular free muscle transfer with cross face nerve grafting. Although the results are promising, the two operations of this method, which are about 1 year apart, impose an economic burden on the patients and require a lengthy period before results are obtained. In order to overcome these drawbacks, one stage method, using latissimus dorsi neurovascuular free muscle flap was introduced. Between January 2000 and January 2004, fifteen patients with long standing facial paralysis were treated in the Korea University Anam Hospital. The segmental latissimus dorsi with long nerve and pedicle was transferred to the paralyzed side of the face. The first postoperative movement of the transferred muscle was reported at 8.9 months, faster than that of the two stage method. During the next 24 months, a constant increase in the power of muscle contraction was observed. The fifteen cases were evaluated within an average of 31.7 months following the surgery and satisfactory results including muscle contraction were obtained in eleven of the cases but muscle contraction was not found in three cases.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.427-428
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• 2007

• 대한두경부종양학회지
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• 제1권1호
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• pp.63-74
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• 1985

Although regional and myocutaneous flaps are still the standard in head and neck reconstruction. The capacity to transfer distant tissues by microsurgical technique expands the reconstructive surgeon's ability to restore severe deformities of the head and neck. From 1981 to 1985, thirteen patients with extensive defects of the head and neck after extirpative surgery of tumor have been reconstructed utilizing the technique of microsurgical composite tissue transplantation. In this series of patients, six presented with reconstructions in the different region of the head and neck with review of literatures. The results of case analysis are summarized as follows: 1) Transplantation was successful in twelve among thirteen patients (92%). 2) Seven patients presented with malignancy and six with benign tumor. 3) Frequent sites of reconstruction were face and mandible. 4) Fourteen free composite tissue transplantations for reconstruction of thirteen patients were obtained six different tissue compositions from eight different donor sites. 5) The recipient artery and vein was most often superficial temporal or facial vessels. 6) The average time of operation was ten hours.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1695-1700
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• 2005

In this paper, we propose an optimal thresholding method for the voxel coloring in the reconstruction of a 3D shape. Our purposed method is a new approach to resolve the trade-off error of the threshold value on determining the photo-consistency in the conventional method. Optimal thresholding value is decided to compare the surface voxel of photo-consistency with inside voxel on the optic ray of the center camera. As iterating the process of the voxels, the threshold value is approached to the optimal value for the individual surface voxel. And also, graph cut method is reduced to the surface noise on eliminating neighboring voxel. To verify the proposed algorithm, we simulated in the virtual and real environment. It is advantaged to speed up and accuracy of a 3D face reconstruction by applying the methods of optimal threshold and graph cut as compare with conventional algorithms.

• 산업공학
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• 제12권2호
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• pp.205-209
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• 1999

In reverse engineering area, the reconstruction of surfaces from scanned or digitized data is being developed, but geometric model of existing objects is not available in industries. This paper presents the new approach to the reconstruction of surface technique. A proposed methodology finds base geometry and blends surface between them. Each based geometry is divided by tri-angular patches which are compared with their normal vector for face grouping. Each group is categorized analytical surface such as a part of cylinder, sphere and cone, and plane shapes to represent the based geometry surface. And then, each based geometry surface is implemented to the infinitive surface. Infinitive surface's intersections are trimmed by boundary representation model reconstruction. This method has several benefits such as time efficiency and automatic functional modeling system in reverse engineering. Especially, it can be directly applied 3D fax and 3D copier.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3782-3796
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• 2020

A three-dimensional (3D) reconstruction is an important research area in computer vision. The ability to detect and match features across multiple views of a scene is a critical initial step. The tracking matrix W obtained from a 3D reconstruction can be applied to structure from motion (SFM) algorithms for 3D modeling. We often fail to generate an acceptable number of features when processing face or medical images because such images typically contain large homogeneous regions with minimal variation in intensity. In this study, we seek to locate sufficient matching points not only in general images but also in face and medical images, where it is difficult to determine the feature points. The algorithm is implemented on an adaptive threshold value, a scale invariant feature transform (SIFT), affine SIFT, speeded up robust features (SURF), and affine SURF. By applying the algorithm to face and general images and studying the geometric errors, we can achieve quasi-dense matching points that satisfy well-functioning geometric constraints. We also demonstrate a 3D reconstruction with a respectable performance by applying a column space fitting algorithm, which is an SFM algorithm.

• 한국정보과학회논문지:시스템및이론
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• 제31권10호
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• pp.593-602
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• 2004

정렬되지 않은 3차원 측정점들로부터 이들을 근사하는 표면을 재구성하는 방법을 제안하였다. 제안된 방법은 경계면 축소포장 방식에 의한 표면 재구성 방법(shrink-wrapped boundary face： SWBF) 으로, 측정점으로부터 경계셀과 경계면을 구해 초기 메쉬를 생성하고 이를 연속적으로 축소하는 방식에 의해 표면을 재구성한다. 제안된 방법은 기존의 표면 축소포장 방식의 메쉬 생성 방법의 문제점인 물체의 토폴로지에 대한 제약이 없이 어떠한 형태의 표면 재구성에도 적용이 가능하며, 기존 방법이 축소 단계에서 각 메쉬 정점에 대한 최단거리 측정점을 찾는 전역 탐색을 해야 하는데 비해 지역 탐색만으로 최적의 측정점을 찾을 수 있으므로 처리 시간 측면에서도 우월하다. 실험을 통해 제안된 표면 재구성 알고리즘이 측정점들간의 관계를 알 수 없는 정렬되지 않은 3차원 점들에 대한 표면 재구성에 매우 안정적이고 효과적임을 확인할 수 있었다.

• Archives of Plastic Surgery
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• 제47권3호
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• pp.277-280
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• 2020

Functionally, the lip serves to prevent food and drink from spilling out of the beginning of the gastrointestinal tract, and it is also used for vocalization. In addition, the lip has cosmetic importance as part of the face involved in making expressions, and in many cultures, it is considered to be sexually appealing. The results of lip reconstruction procedures must therefore be both functionally and cosmetically satisfactory. When the orbicularis oris muscle and oral mucosa are excised, functional reconstruction is prioritized. In contrast, if there are no functional problems, cosmetic reconstruction is the main focus. This case involved the reconstruction of a right upper lip defect caused by a dog bite. When the skin defect was covered with a local flap, the right angulus oris shifted medially, so we incorporated a YV flap at the right angulus oris to modify its position and allow for a cosmetically satisfactory result. We believe that this method can be used not only for cases in which asymmetry of the angulus oris is expected to occur at the time of lip reconstruction, but also for cases in which it has already occurred in the initial operation.

• 한국멀티미디어학회논문지
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• 제10권2호
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• pp.179-186
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• 2007

본 논문에서는 Zernike 모멘트를 이용한 새로운 얼굴 검출 기법을 제안한다. 입력 영상을 가변 크기의 영역으로 탐색하면서 Zernike 모멘트를 계산하여 신경망에 의해 얼굴과 비얼굴 영역으로 분류하여 얼굴을 검출한다. 직교 모멘트의 재구성 능력으로 인해, 분류기의 입력 특정은 화소의 수에 비해 감소될 수 있다. 또한, Zernike 모멘트의 크기는 회전에 불변한 특정을 가지므로, 회전된 얼굴 영역을 검출할 수 있다. Yale 데이터베이스의 영상에 대해 적용한 결과, 회전되지 않은 영상에서는 밝기값 정보를 사용하는 기법보다 약간 낮은 성능을 보였지만, 회전된 영상에 대해서는 월등히 높은 성능을 보였다. 국부 조명에 대한 추가적인 보상과 특징이 사용된다면, 강건한 얼굴 인식을 위한 전처리 과정의 핵심 기술로 사용할 수 있을 것이다.