• Title/Summary/Keyword: line reconstruction

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Three Dimensional Building Construction Based on LIDAR Data (LIDAR 자료기반의 3차원 건물정보 구축)

  • Yoo, Hwan-Hee;Kim, Kyung-Whan;Kim, Seong-Sam
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.3 s.37
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    • pp.13-22
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    • 2006
  • Realistic 3D building construction in urban area has become an important issue because of increasing demand of 3D geo-spatial information in many application. Contrary to the conventional 3D building model construction approach using aerial images and high-resolution satellite imagery, it has been researched widely in building reconstruction using high-accuracy aerial LIDAR data in the latest. This paper presents a method for 3D building construction through building outlines extraction by LoG operator's Zero-crossing and line generation and refinement by Douglas-Peucker algorithm.

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Design of Robust Adaptive Fuzzy Controller for Uncertain Nonlinear System Using Estimation of Bounding Constans and Dynamic Fuzzy Rule Insertion (유계상수 추정과 동적인 퍼지 규칙 삽입을 이용한 비선형 계통에 대한 강인한 적응 퍼지 제어기 설계)

  • Park, Jang-Hyun;Park, Gwi-Tae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.1
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    • pp.14-21
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    • 2001
  • This paper proposes an indirect adaptive fuzzy controller for general SISO nonlinear systems. In indirect adaptive fuzzy control, based on the proved approximation capability of fuzzy systems, they are used to capture the unknown nonlinearities of the plant. Until now, most of the papers in the field of controller design for nonlinear system considers the affine system using fuzzy systems which have fixed grid-rule structure. We proposes a dynamic fuzzy rule insertion scheme where fuzzy rule-base grows as time goes on. With this method, the dynamic order of the controller reduces dramatically and an appropriate number of fuzzy rules are found on-line. No a priori information on bounding constants of uncertainties including reconstruction errors and optimal fuzzy parameters is needed. The control law and the update laws for fuzzy rule structure and estimates of fuzzy parameters and bounding constants are determined so that the Lyapunov stability of the whole closed-loop system is guaranteed.

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Terrain Reconstruction from Contour Lines (등고선을 이용한 지형 재구성)

  • Kim, Sung-Soo;Lee, Seong-Ho;Lee, Jong-Hun;Yang, Young-Kyu
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.10a
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    • pp.641-644
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    • 2001
  • 기존의 종이지도를 수치지도 처리과정으로 얻어진 등고선(contour line) 데이터는 원격탐사(Remote Sensing)와 지리정보시스템(GIS)의 응용분야에서 주로 사용되어지는 데이터이다. 이러한 등고선은 해당 지역의 DTM(Digital Terrain Model) 데이터 생성을 위해 보간(interpolation)하여 생성하는 데 연구가 집중되어 왔다. 본 논문에서는 DEM(Digital Elevation Model)으로부터 얻어진 등고선 데이터를 이용하여 사용자에게 3 차원으로 가시화 해 줄 수 있는 기법을 소개한다. 등고선 추출을 위한 방법으로는 기존의 소개되어진 Marching Square 알고리즘을 적용하였고, 지역적인 최고점(local minimum)과 최소점(maximum)을 구하기 위해 등고선을 열린 등고선(open contour)과 닫힌 등고선(closed contour)으로 분류하게 된다. 지역적 최고, 최소점을 찾기 위한 탐색공간을 줄이기 위해 닫힌 등고선만을 대상으로 등고선 트리를 생성하였으며, 생성된 트리의 리프노드에 대해서 최고, 최소점에 대한 근사(approximation)를 수행하게 된다. 이렇게 구해진 근사된 정점들과 등고선 데이터를 입력으로 하여 제한된 딜로니 삼각분할(Constrained Delaunay Triangulation)을 수행함으로써, 3 차원 지형을 재구성할 수 있다. 실험에서 USGS 로부터 획득한 지형 데이터를 이용하여 속도 측정을 하였다. 결과적으로 저장공간 측면에서 적은 량의 데이터를 가지면서 등고선을 표현할 수 있는 3 차원 지형을 렌더링 할 수 있음을 알 수 있다.

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Study of Stripe Pattern Appeared in Apparel Design - Focusing on Western Women's Fashion after 20th Centuries - (의상(衣裳) 디자인의 줄무늬(Stripe Pattern) 연구(硏究) - 20세기(世紀) 이후(以後) 서양(西洋) 여성(女性) 패션을 중심(中心)으로 -)

  • Kim, Ju-Eun;Cho, Kyu-Hwa
    • Journal of Fashion Business
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    • v.6 no.4
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    • pp.99-112
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    • 2002
  • The purpose of this study is to find out various types of stripes pattern and to review its' design expression by analysing stripe pattern and visual effect appeared in western women's fashion after 20th centuries. As regards the visual effect of stripe pattern, on the basis of the stripe pattern's direction laid out, we made an investigation of it by classfying it into verticality, horizontality, slant line and mixture of them according to its' gap and thickness. Here are the 4 features of the stripe pattern appeared in modern fashions. The first, graphic variation based on diverse variation and reconstruction and combination between other motives is being onthe rise as a new expression. The second, colorful stripes of Missoni can be exanpled as the trend of diversification of color. The third, as regards the trend of mismatch in pattern, coordination through mismatch can produce experimental and post-modern image. The fourth, as for the expression of draping effect, we find that stripe pattern can maximaze visual effect through draping by inducing visual stimulus, as well as can express human body in a beautiful manner.

Being a front-line dentist during the Covid-19 pandemic: a literature review

  • Fallahi, Hamid Reza;Keyhan, Seied Omid;Zandian, Dana;Kim, Seong-Gon;Cheshmi, Behzad
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.12.1-12.9
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    • 2020
  • Coronavirus is an enveloped virus with positive-sense single-stranded RNA. Coronavirus infection in humans mainly affects the upper respiratory tract and to a lesser extent the gastrointestinal tract. Clinical symptoms of coronavirus infections can range from relatively mild (similar to the common cold) to severe (bronchitis, pneumonia, and renal involvement). The disease caused by the 2019 novel coronavirus (2019-nCoV) was called Covid-19 by the World Health Organization in February 2020. Face-to-face communication and consistent exposure to body fluids such as blood and saliva predispose dental care workers at serious risk for 2019-nCoV infection. As demonstrated by the recent coronavirus outbreak, information is not enough. During dental practice, blood and saliva can be scattered. Accordingly, dental practice can be a potential risk for dental staff, and there is a high risk of cross-infection. This article addresses all information collected to date on the virus, in accordance with the guidelines of international health care institutions, and provides a comprehensive protocol for managing possible exposure to patients or those suspected of having coronavirus.

Development of Underwater Laser Scanner with Efficient and Flexible Installation for Unmanned Underwater Vehicle (무인잠수정을 위한 효과적이고 유연한 설치 성능을 지닌 수중 레이저스캐너 개발)

  • Lee, Yeongjun;Lee, Yoongeon;Chae, Junbo;Choi, Hyun-Taek;Yeu, Tae-Kyeong
    • Journal of Ocean Engineering and Technology
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    • v.32 no.6
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    • pp.511-517
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    • 2018
  • This paper proposes a vision-based underwater laser scanner with separate structures for an underwater camera and a line laser projector. Because the two devices can be adaptively placed regardless of the features of the unmanned underwater vehicle (UUV), the scanner has significant advantages in relation to its availability and flexibility. Position calibration between the underwater camera and laser projector guarantees a 3D measuring performance with high accuracy. To verify the proposed underwater laser scanner, a test-bed system was manufactured, which consisted of the laser projector, camera, Pan&Tilt, and Attitude and Heading Reference System (AHRS). A camera-laser calibration test and simple 3D reconstruction test were performed in a water tank and the experimental results are reported.

A new conjugate gradient method for dynamic load identification of airfoil structure with randomness

  • Lin J. Wang;Jia H. Li;You X. Xie
    • Structural Engineering and Mechanics
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    • v.88 no.4
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    • pp.301-309
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    • 2023
  • In this paper, a new modified conjugate gradient (MCG) method is presented which is based on a new gradient regularizer, and this method is used to identify the dynamic load on airfoil structure without and with considering random structure parameters. First of all, the newly proposed algorithm is proved to be efficient and convergent through the rigorous mathematics theory and the numerical results of determinate dynamic load identification. Secondly, using the perturbation method, we transform uncertain inverse problem about force reconstruction into determinate load identification problem. Lastly, the statistical characteristics of identified load are evaluated by statistical methods. Especially, this newly proposed approach has successfully solved determinate and uncertain inverse problems about dynamic load identification. Numerical simulations validate that the newly developed method in this paper is feasible and stable in solving load identification problems without and with considering random structure parameters. Additionally, it also shows that most of the observation error of the proposed algorithm in solving dynamic load identification of deterministic and random structure is respectively within 11.13%, 20%.

Correction of Upper Lip Depression Using Conchal Cartilage Graft in Unilateral Cleft Lip Deformity (일측구순열변형에서 이갑개연골이식술을 이용한 상구순 함몰의 교정)

  • Han, Ki-Hwan;Yun, Sang-Ho;Yeo, Hyun-Jung;Kim, Jun-Hyung;Son, Dae-Gu
    • Archives of Plastic Surgery
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    • v.38 no.4
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    • pp.383-390
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    • 2011
  • Purpose: To correct the upper lip depression after the correction of unilateral cleft lip, autologous grafts such as bone, dermal, fascial grafts and fat injections or alloplastic implants are used. Transplanted bones, dermis and fascia have a tendency to be absorbed and have donor morbidity. Fat injections are absorbed inconsistently and alloplastic implants have problems such as foreign body reactions, protrusions and infections. Authors corrected the upper lip depression using conchal cartilage graft in unilateral cleft lip deformity and the results was analysed with photos. Methods: 26-unilateral cleft lip and 2-microform cleft lip cases, totally 28 cases were performed. Their mean age was 21.89 years. The male and female cases were 12 and 16, respectively. Under anesthesia (general: 18 cases and local: 10 cases), cavum conchae (n=8), cymba conchae (n=16) and whole conchae (n=4) were harvested. Transversely cut the margin of the obtained cartilage, we cut out the most bent portion and put a partial-thickness incision on concave surface in cases of excessive convexity. Then, we performed the onlay graft of the conchal cartilage via scar revision site in unilateral cleft lip and via the reconstruction site of the cupid bow in microform cleft lip. The augmentation of the upper lip was evaluated with photos. Adapting the baseline connecting between the both cheilions as a horizontal standard line, we measured the highest point among the tangents between the upper lip and nose (point a), the lowest point (point c), the middle point between a and c (point b) and the vertical line from the alare (point d) to the horizontal standard line. To assess the postoperative symmetry, we compared cleft side upper lip contour index (%) A,B,C,D=(a,b,c,d)-ch ${\times}$ 100/(ch-ch) and non-cleft side upper lip contour index (%) A',B',C',D'= (a',b',c',d')-ch ${\times}$ 100 / (ch-ch).h) Results: After the surgery, no complication was found except in one case which double layers graft performed in the cleft lip deformity, the lateral portion was protruded. The upper lip contour index, the difference of A and A' were-0.83%, and thus the mild depression was persisted. Difference of B and B', C and C', D and D' were 0.83%, 1.07%, 0.90%. There were statistically significant difference, and thus the depression of upper lip were improved generally. Conclusion: Authors performed the onlay graft of the conchal cartilage in unilateral cleft lip deformity and found that the depression of the upper lip was well corrected except the uppermost part when photogrammetrically analyzed.

Development of the 3D Rail Profile Reconstruction Method Improving the Measurement Accuracy of Railway Abrasion (레일 마모도의 측정 정밀도 향상을 위한 3차원 레일 프로파일 재구성 기법 개발)

  • Ahn, Sung-Hyuk;Kim, Man-Cheol
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.533-539
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    • 2010
  • The The contactless railway abrasion measurement system have to satisfy two conditions to increase the measurement accuracy as follows. The laser region projected on the rail have to be extracted without the geometrical distortion. The mapping of the acquired laser region data on the rail profile have to be matched with the cross section of rail, exactly. But, the conventional railway abrasion measurement system is required the post image processing with a camera model and a perspective transform for the exact mapping between the cross section of rail and the coordinate data extracted from a line laser region or the raw image obtained from a camera because the image captured from the camera has an oblique viewpoint. So, the measured rail profile data had limits to the measurement accuracy because of a discontinuity point. In this Paper, we propose the 3D rail profile reconstruction method to increase the accuracy of the railway abrasion measurement system applying the modified camera model and perspective transform to the image obtained from the bidirectional rail.

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Recovery of Lithospheric Magnetic Component in the Satellite Magnetometer Observations of East Asia (인공위성 자력계에서 관측된 동아시아 암권의 지자기이상)

  • Kim, Jeong-Woo
    • Geophysics and Geophysical Exploration
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    • v.5 no.3
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    • pp.157-168
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    • 2002
  • Improved procedures were implemented in the production of the lithospheric magnetic anomaly map from Magsat satellite magnetometer data of East Asia between $90^{\circ}E-150^{\circ}E$ and $10^{\circ}S-50^{\circ}N$. Procedures included more effective selection of the do·it and dawn tracks, ring current correction, and separation of core field and external field effects. External field reductions included an ionospheric correction and pass-by-pass correlation analysis. Track-line noise effects were reduced by spectral reconstruction of the dusk and dawn data sets. The total field magnetic anomalies were differentially-reduced-to-the-pole to minimize distortion s between satellite magnetic anomalies and their geological sources caused by corefield variations over the study area. Aeromagnetic anomalies were correlated with Magsat magnetic anomalies at the satellite altitude to test the lithospheric veracity of anomalies in these two data sets. The aeromagnetic anomalies were low-pass filtered to eliminate high frequency components that may not be shown at the satellite altitude. Although the two maps have a low CC of 0.243, there are many features that are directly correlated (peak-to-peak and trough-to-trough). The low CC between the two maps was generated by the combination of directly- and inversely-correlative anomaly features between them. It is very difficult to discriminate directly, inversely, and nully correlative features in these two anomaly maps because features are complicatedly correlated due to the depth and superposition of the anomaly sources. In general, the lithospheric magnetic components were recovered successfully from satellite magnetometer observations and correlated well with aeromagnetic anomalies in the study area.