• 한국자동차공학회논문집
• /
• 제17권2호
• /
• pp.49-56
• /
• 2009

In this study, a side collision accident reconstruction using database based on the deformed shape information from the collision test using model cars is suggested. A deformation index and angle index related to the deformed shape is developed to set the database for the collision accident reconstruction algorithm. Two small size RC cars are developed to carry out the side collision test. Several side collision tests according to the velocity and collision angles are performed for establishing the side collision database. A high speed camera with 1000fps is used to capture the motion of the car. A side collision accident reconstruction algorithm is developed and applied to find the collision conditions before the accident occurs. Two collision cases are tested to validate the database and the algorithm. The results obtained by the reconstruction algorithm show good match with original conditions with regard to the velocity and angle.

• Archives of Plastic Surgery
• /
• 제35권5호
• /
• pp.539-544
• /
• 2008

Purpose: There have been limited reports on breast reconstruction after excision of phyllodes tumor. This paper reports four patients who had immediate reconstruction of the breast following excision of phyllodes tumor. Methods: We retrospectively reviewed the medical records of 14 patients from March 2000 to March 2008. Clinical data were analyzed including age, presenting symptoms and signs, type of surgery and metastasis. Results: The mean age was 38.6 years. The mean follow-up period was 40.6 months. Reconstruction was performed with latissimus dorsi musculocutaneous flap in 3 patients and transverse rectus abdominis musculocutaneous flap in 1 patient. Other cases were covered with skin graft or primary repair. 2 local recurrent cases were noted. Conclusion: The breast affected by phyllodes tumor must undergo complete excision. Followed by mastectomy, immediate reconstruction of breast improved cosmetic results, and allowed a wider surgical excision margin of tumor.

• 로봇학회논문지
• /
• 제4권4호
• /
• pp.298-304
• /
• 2009

This paper describes an algorithm that improves 3D reconstruction result using a multi-sensor fusion disparity map. We can project LRF (Laser Range Finder) 3D points onto image pixel coordinatesusing extrinsic calibration matrixes of a camera-LRF (${\Phi}$, ${\Delta}$) and a camera calibration matrix (K). The LRF disparity map can be generated by interpolating projected LRF points. In the stereo reconstruction, we can compensate invalid points caused by repeated pattern and textureless region using the LRF disparity map. The result disparity map of compensation process is the multi-sensor fusion disparity map. We can refine the multi-sensor 3D reconstruction based on stereo vision and LRF using the multi-sensor fusion disparity map. The refinement algorithm of multi-sensor based 3D reconstruction is specified in four subsections dealing with virtual LRF stereo image generation, LRF disparity map generation, multi-sensor fusion disparity map generation, and 3D reconstruction process. It has been tested by synchronized stereo image pair and LRF 3D scan data.

• 대한교통학회지
• /
• 제25권4호
• /
• pp.69-77
• /
• 2007

본 연구에서는 보행자-차량 충돌사고 분석을 위한 국내외 사고재현모형을 비교하였다. 충돌 후 보행자의 전도거리를 종속변수로, 차량의 충돌속도를 독립변수로 하는 모형을 비교하였으며, 수집된 총 432건의 사고 자료 중 신뢰성 있는 전도거리와 충돌속도 자료의 확보가 가능한 49건을 선정하여 절대평균백분위오차를 산출 후 비교하였다. 또한 전도거리에 영향을 새로운 변수의 도출을 위해 차량의 전면부 형상을 조사하고 이를 변수화하여 모형 구축에 반영하였다. 분석결과 차량의 범퍼높이가 다른 변수에 비해 전도거리에 큰 영향을 미치는 것으로 나타났다. 향후 연구에서는 보다 폭넓고 많은 데이터 수집 및 분석을 통하여 신뢰성을 높은 모형개발이 이루어져야 할 것이다.

• 설비공학논문집
• /
• 제11권6호
• /
• pp.749-757
• /
• 1999

Holographic interferornetric tomography can provide reconstruction of instantaneous three dimensional gross flow fields. The technique however confronts ill-posed reconstruction problems in practical applications. Experimental data are usually limited in projection and angular scanning when a field is captured instantaneously or under the obstruction of test models and test section enclosures. An algorithm, based on a series expansion method, has been developed to improve the reconstruction under the ill-posed conditions. A three-dimensional natural convection flow around two interacting isothermal cubes is experimentally investigated. The flow can provide a challenging reconstruction problem and lend itself to accurate numerical solution for comparison. The refractive index fields at two horizontal sections of the thermal plume with and without an opaque object are reconstructed at a limited view angle of 80" The experimental reconstructions are then compared with those from numerical calculation and thermocouple thermometry. It confirms that the technique is applicable to reconstruction of reasonably complex, three-dimensional flow fields.elds.

• Archives of Plastic Surgery
• /
• 제48권1호
• /
• pp.114-120
• /
• 2021

Background The pedicled anterolateral thigh (ALT) flap has become more popular for the reconstruction of soft-tissue defects in neighboring areas. Nonetheless, few studies in the literature have explored the use of this flap for trochanteric ulcer reconstruction. The aim of our study is to present the author's experience of utilizing the ALT flap, with a focus on technical elements regarding the flap design and the tunneling method to maximize the reach of the flap. Methods The medical records of patients who received pedicled ALT flaps for the reconstruction of trochanteric pressure sores were retrospectively reviewed. The patients' demographic data, operative details, and postoperative complications were evaluated. Results Between October 2018 and December 2019, 10 consecutive patients (age range, 13-45 years) underwent 11 pedicled ALT myocutaneous flaps for trochanteric pressure sore reconstruction. Each flap was designed around the most distal cutaneous perforator that was included in the proximal third of the skin paddle. The flaps ranged in size from 11×6 to 14×8 cm. The ALT flap was transposed through a lateral subcutaneous tunnel in five patients, while the open tunnel technique was used in six patients. All flaps survived, and no vascular compromise was observed. Conclusions The pedicled ALT flap is a safe and reliable option for reconstructing trochanteric pressure sores. An appropriate flap design and a good choice of the tunneling method are crucial for successful flap transposition.

• 대한전자공학회논문지
• /
• 제17권1호
• /
• pp.14-22
• /
• 1980

이차원 영상 재구성을 위해서는 Fouler convolution 알고리즘이 주로 사용되고 있다. 이때 사용되는 필터의 설계에는 몇가지 선택의 여지가 있다. 이 논문은 지금까지 제안된 영상 재구성 필터들을 sampling rate와 aliasing과 잡음의 견지에서 이론적으로 비교, 검토하고 이를 토대로 새로운 필터의 설계방법을 제안하였다. 또한 컴퓨터 simulation을 통해 기존의 재구성 필터와 제안된 필터의 이론적인 분석 결과를 확인, 검토하였다.

• 융복합기술연구소 논문집
• /
• 제10권1호
• /
• pp.7-12
• /
• 2020

We describe a efficient surface reconstruction method that reconstructs a 3D manifold polygonal mesh approximately passing through a set of 3D oriented points. Our algorithm includes 3D convex hull, octree data structure, signed distance function (SDF), and marching cubes. The 3D convex hull provides us with a fast computation of SDF, octree structure allows us to compute a minimal distance for SDF, and marching cubes lead to iso-surface generation with SDF. Our approach gives us flexibility in the choice of the resolution of the reconstructed surface, and it also enables to use on low-level PCs with minimal peak memory usage. Experimenting with publicly available scan data shows that we can reconstruct a polygonal mesh from point cloud of sizes varying from 10,000 ~ 1,000,000 in about 1~60 seconds.

• 대한의용생체공학회:의공학회지
• /
• 제15권4호
• /
• pp.413-418
• /
• 1994

In electrical impedance tomography (EIT), we use boundary current and voltage measurements to provide the information about the cross-sectional distribution of electrical impedance or resistivity One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.7T NMR machine. We implemented a resistivity image reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the image reconstruction algorithm and furture direction of the research.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제18권2호
• /
• pp.167-180
• /
• 2014

In this paper we consider a novel reconstruction method in electrical impedance tomography (EIT) and its application for monitoring and detecting a hydrargyrum (mercury) polluted soil near to the surface of underground. We use electrodes placed on the surface of land to collect the data which provides the relations of voltage and current map and to produce a projected image of interior conductivity distribution onto the surface of land. Here the projected image reconstruction method is used to monitor the pollution in soil underneath the ground without any destruction and any digging into a land.