• 제목/요약/키워드: Global Mapping

검색결과 356건 처리시간 0.034초

DGPS/IMU-based Photogrammetry in China

  • Yingcheng, Li;Xueyou, Li;Jicheng, Zhao;Xunping, Gong;Tang, Liang
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1215-1220
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    • 2003
  • People's Republic of China is one of the most rapidly developing countries in the world today. There is a great demand on highly actual and accurate spatial information of the whole country, especially of West China which becomes the focus of development of the Chinese government right now and in the next years, but where still not enough topographic maps are available. This raises great challenges to the surveying and mapping community in China. Facing the new challenges the Chinese Academy of Surveying and Mapping (CASM) started its pioneer work early 2002 to explore new techniques and technologies available today toward increasing the map productivity. With import of a CCNS/AEROcontrol system in November 2002 the first DGPS/IMU-based photogrammetric project in China was successfully accomplished jointly by CASM and the Germany-based companies IGI and Techedge. Two photogrammetric blocks of 1:4,000 and 1:20,000 photo scale, respectively, were flown in Anyang, China. Direct georeferencing and integrated sensor orientation were conducted. Results achieved were proven by using ground check points and compared with those of aerial triangulation. Orthophotos generated based on direct georeferencing shows the high efficiency and quality, and thus proved the promise of the new technology. Furthermore several DGPS/IMU-based photogammetric projects was accomplished one by one and a big project of more than 100,000 km2 in the Inner Mongolia will be started in August 2003. The paper presents experiences with DGPS/IMU-based photogrammetry in China. Results achieved in concrete projects are shown and evaluated. Politic and technical specialties in China are discussed. Conclusions outline the potential of DGPS/IMU-based photogrammetric production in China.

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다이나믹 레인지 최적화를 통한 영상 화질 개선 알고리즘 (Image Enhancement Algorithm using Dynamic Range Optimization)

  • 송기선;김민섭;강문기
    • 전자공학회논문지
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    • 제53권6호
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    • pp.101-109
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    • 2016
  • 카메라 센서는 사람의 눈에 비해 제한적인 다이나믹 레인지를 갖기 때문에 영상 획득 시 실제 보이는 것과 다른 모습의 영상을 획득하게 된다. 이러한 문제를 영상 처리를 통해 해결하고자 톤 맵핑 함수를 이용한 방법들과 사람의 눈을 모델링한 레티넥스 이론 기반의 방법들이 연구되었다. 하지만 이러한 방법들은 후광 효과가 발생하거나 영상 개선 시 전역 또는 국부 콘트라스트 향상이 제한적이라는 단점이 있다. 제안하는 방법에서는 영상의 광원 정보를 레티넥스 이론을 활용하여 추정한 후 이를 영상의 품질 향상을 위해 다이나믹 레인지를 최적화시키는데 이용한다. 이 과정에서 후광 효과가 발생하는 것을 방지하기 위해 유사 밝기 영역에서만 평탄화가 이루어지고 밝기 차가 나는 영역은 밝기 차를 유지하도록 한다. 또한 톤 맵핑 함수 적용 시 하나의 화소가 아닌 주변 영역 정보와 추정된 광원 정보를 모두 고려하여 전역 및 국부 콘트라스트가 동시에 향상되는 알고리즘을 제안한다. 실험 결과들을 통해 제안하는 방법이 기존 방법에 비해 국부 콘트라스트 수치가 약 0.4 향상 되었고, 시각적인 면에서도 콘트라스트 향상과 함께 암부와 명부를 동시에 효과적으로 표현한 것을 확인 할 수 있다.

한국화 모티브를 활용한 어패럴용 텍스타일 CAD 디자인 (Textile Design with CAD for Apparel Employing Motives from Korean Traditional Paintings)

  • 김칠순;조용주
    • 한국의상디자인학회지
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    • 제10권3호
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    • pp.101-110
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    • 2008
  • We believe distinguishable product development to be competitive against foreign products, and realize the need to expand domestic business worldwide. In order to be competitive, we should produce fashion items that meets global taste, and at the same time contain exclusive Korean culture and emotional beauty. This article examines and creates unique textile design with the touch of Korean art. Desigus have been proceeded under the following three themes: 'Strong Ego,' 'Gorgeous Days' and 'Song Eternal Seeking Love' using Primavision Computer-aided Design ("CAD"). We have put our interestes in Korean traditional paintings called Hangukhwa. Suitable design motives had been selected and modified from the four gracious plants (bamboos, peonies etc.), and paintings of birds and flowers. Primavision, a CAD software, had been used to manipulate those desigus, and to add instant changes in color, scale, and layout. We had modified Korean traditional motives to make modem image, and had arranged layouts which can be suitable for half-drop repeat and square repeat. The use of color is essential in pattern design. Thus, we explored coloring ways for each design to meet the trends, and the final mapping had been conducted in western style of dresses. We have tried to mix Korean image of textile designs with Western clothing style, expressing hybrid in the mapping process. With global movements, we need to develop products with Korean traditional exotic taste to attract foreign consumers. Therefore, we selected symbolic motives from Korean paintings to express deep spiritual significance. We developed textile design and processed mapping on selected western designer's dress, employing current trend colors and making crossover coordination. We realized Korean painting would be an excellent source for exclusive fabric design, and tried to create a modernized design which maintains Korean ethnical identities.

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Accuracy Analysis of Image Orientation Technique and Direct Georeferencing Technique

  • Bae Sang-Keun;Kim Byung-Guk
    • Spatial Information Research
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    • 제13권4호
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    • pp.373-380
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    • 2005
  • 모바일매핑시스템은 차량에 GPS(Global Positioning System), IMU(Inertial Measurement Unit), CCD 등을 탑재하고 대상에 관한 위치 및 영상 정보를 취득하는 효율적인 시스템이다. 모바일매핑시스템은 현재 도로 시설물 관리, 지도 갱신 등 다양한 분야에 활용되고 있으며 앞으로 그 활용도가 더욱 증가할 것으로 보인다. 항공사진측량과 같은 기존의 일반적인 사진측량의 경우, 영상 외부표정요소를 구하기 위해서는 지상기준점이 필요하다. 이러한 기준점들은 자료취득 전후에 현장측량을 통해 좌표가 결정되는데 일반적으로 많은 비용과 시간이 소요되고, 사실 영상을 취득할 도로를 따라 필요한 만큼 충분히 많은 기준점을 설치한다는 것도 거의 불가능하다. 하지만 모바일매핑 시스텔의 경우 GPS/INS를 이용해 영상촬영당시의 카메라의 위치 및 자세, 즉 외부표정요소를 직접적으로 구할 수 있어 시간과 비용 면에서 훨씬 효율적이다. 즉 외부표정요소를 결정하기 위해 영상표정기법은 지상기준점이 필요한 반면, 직접위치참조기법은 GPS/INS를 이용해 직접 외부표정요소를 구할 수 있다. 본 논문에서는 영상표정 기법과 직접위치참조기법에서 산출되는 영상외부표정요소를 이용해 지상점의 위치정확도에 대해 비교 분석해 보았다.

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A copula based bias correction method of climate data

  • Gyamfi Kwame Adutwum;Eun-Sung Chung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.160-160
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    • 2023
  • Generally, Global Climate Models (GCM) cannot be used directly due to their inherent error arising from over or under-estimation of climate variables compared to the observed data. Several bias correction methods have been devised to solve this problem. Most of the traditional bias correction methods are one dimensional as they bias correct the climate variables separately. One such method is the Quantile Mapping method which builds a transfer function based on the statistical differences between the GCM and observed variables. Laux et al. introduced a copula-based method that bias corrects simulated climate data by employing not one but two different climate variables simultaneously and essentially extends the traditional one dimensional method into two dimensions. but it has some limitations. This study uses objective functions to address specifically, the limitations of Laux's methods on the Quantile Mapping method. The objective functions used were the observed rank correlation function, the observed moment function and the observed likelihood function. To illustrate the performance of this method, it is applied to ten GCMs for 20 stations in South Korea. The marginal distributions used were the Weibull, Gamma, Lognormal, Logistic and the Gumbel distributions. The tested copula family include most Archimedean copula families. Five performance metrics are used to evaluate the efficiency of this method, the Mean Square Error, Root Mean Square Error, Kolmogorov-Smirnov test, Percent Bias, Nash-Sutcliffe Efficiency and the Kullback Leibler Divergence. The results showed a significant improvement of Laux's method especially when maximizing the observed rank correlation function and when maximizing a combination of the observed rank correlation and observed moments functions for all GCMs in the validation period.

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ELLIPTIC BIRKHOFF'S BILLIARDS WITH $C^2$-GENERIC GLOBAL PERTURBATIONS

  • Kim, Gwang-Il
    • 대한수학회보
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    • 제36권1호
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    • pp.147-159
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    • 1999
  • Tabanov investigated the global symmetric perturbation of the integrable billiard mapping in the ellipse [3]. He showed the nonintegrability of the Birkhoff billiard in the perturbed domain by proving that the principal separatrices splitting angle is not zero.In this paper, using the exact separatrix map of an one-degree-of freedom Hamiltoniam system with time periodic perturbation, we show the existence the stochastic layer including the uniformly hyperbolic invariant set which implies the nonintegrability near the separatrices of a Birkhoff's billiard in the domain bounded by $C^2$ convex simple curve constructed by the generic global perturbation of the ellipse.

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Mapping World History in Korea

  • HWANGBO, Yeongjo
    • Asian review of World Histories
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    • 제3권2호
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    • pp.235-253
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    • 2015
  • It has been about twenty years since world history in a new sense was introduced to Korean academia. At first, it was the educators who showed a lot of interest in world history. But, before long, world/global history came to exert an important influence on history research and teaching in Korea. Even though certain unfavorable conditions still exist, the need for world/global history is growing and a number of academic institutes and scholars are putting in a great deal of effort to advance it in Korea. Here, we examine the changing meanings of world history on the basis of the history of concepts and provide a general idea of its introduction and diffusion in historiography and history education in Korea.

Visual SLAM을 통해 획득한 공간 지도의 완성도 평가 시스템 (An Evaluation System to Determine the Completeness of a Space Map Obtained by Visual SLAM)

  • 김한솔;감제원;황성수
    • 한국멀티미디어학회논문지
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    • 제22권4호
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    • pp.417-423
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    • 2019
  • This paper presents an evaluation system to determine the completeness of a space map obtained by a visual SLAM(Simultaneous Localization And Mapping) algorithm. The proposed system consists of three parts. First, the proposed system detects the occurrence of loop closing to confirm that users acquired the information from all directions. Thereafter, the acquired map is divided with regular intervals and is verified whether each area has enough map points to successfully estimate users' position. Finally, to check the effectiveness of each map point, the system checks whether the map points are identifiable even at the location where there is a large distance difference from the acquisition position. Experimental results show that space maps whose completeness is proven by the proposed system has higher stability and accuracy in terms of position estimation than other maps that are not proven.

Comparison of Convolutional Neural Network Models for Image Super Resolution

  • Jian, Chen;Yu, Songhyun;Jeong, Jechang
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2018년도 하계학술대회
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    • pp.63-66
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    • 2018
  • Recently, a convolutional neural network (CNN) models at single image super-resolution have been very successful. Residual learning improves training stability and network performance in CNN. In this paper, we compare four convolutional neural network models for super-resolution (SR) to learn nonlinear mapping from low-resolution (LR) input image to high-resolution (HR) target image. Four models include general CNN model, global residual learning CNN model, local residual learning CNN model, and the CNN model with global and local residual learning. Experiment results show that the results are greatly affected by how skip connections are connected at the basic CNN network, and network trained with only global residual learning generates highest performance among four models at objective and subjective evaluations.

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Evaluation of SPECT Analysis in Patients with Transient Global Amnesia

  • Choe, Bo-Young;Kim, Euy-Neyng;Chung, Yong-An;Sohn, Hyung-Sun;Kim, Sung-Hoon;Chung, Soo-Kyo;Lee, Hyoung-Koo;Suh, Tae-Suk
    • 한국자기공명학회논문지
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    • 제6권1호
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    • pp.45-53
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    • 2002
  • Objectives: This study investigated alterations in regional cerebral blood flow (rCBF) in patients with transient global amnesia (TGA) using statistical parametric mapping 99 (SPM99). Methods: Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 8 patients with TGA who have ongoing symptoms and 17 age matched controls. The relative rCBF maps in patients with TGA and controls were compared. Results: In patients with TGA, significant decreased rCBF was found along the L superior temporal extending to L parietal region of the brain and L thalamus. There were areas of increased rCBF in the R temporal, R frontal region and R thalamus. Conclusion: We could demonstrate decreased perfusion in left cerebral hemisphere and increased perfusion in right cerebral hemisphere in patients with TGA using SPM99. The imbalanced change of rCBF between bilateral cerebral hemisphere in patients with TGA might suggest that imbalanced neuronal activity between the bilateral hemispheres may have strong relationship to the pathogenesis of the TGA. For quantitative SPECT analysis in TGA patients, we recommend SPM99 rather than the ROI method because of its definitive advantages.

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