• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.119-132
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• 1998

Much information on the terrain and the space has been depicted to maps of various form according to the map scale and the application. In Korea the base map system was made by only one projection method(Transvers Mercator projection). This is the reason to study this paper, because I think singular map projection method can't satisfy the various map scales and application. In this paper Meridian Are Length, Parallel Are Length of ellipsoid and the area of ellipsoidal surface-the length, the width and area of the map scale 1/5,000, 1/25,000, 1/5,000, 1/1,000, will be calculated and transformed to the plane length and area by Transvers Mercartor projection and Polyhedrical projection. The projection distortion which came into existence on this occasion was compared and analyzed by this Paper. And Properties on TM and Polyhedrical projection were understood. Lastly this paper intended to present suitable map projections according to the map scales and the purpose of use.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.699-704
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• 2006

본 논문은 회전 및 천이불변 이미지 텍스처 검색의 새로운 방식을 소개한다. 주파수 영역의 극좌표계에서 동일한 공간 주파수에서 각도 방향으로 투영을 하는 각도 투영법을 제안하며, 제안된 각도 투영법을 이용하여 주파수 영역에서 푸리에 계수이 합과 표준편차를 특징벡터로 이용한다. 각도 투영법을 쉽게 구현하기 위해 극좌표계에서 라돈변환이 수행된다. 실험 시 MPEG-7 데이터를 이용하였으며 그 결과는 여러 텍스처 이미지를 검색하는데 있어서 특징을 잘 구별해 내는 결과를 보여준다. 또한 제안된 회전 및 천이불변 특징 추출 알고리듬은 등방성 텍스처나 국부적인 방향성을 보이는 텍스처 영상 검색에도 효율적인 검색률을 보인다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.337-343
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• 1998

In Korea, map coordinates has been confused in use since the map projection system has been complicated by using two different methods i.e., Gauss conformal double projection and Gauss-Kruger projection which are com-plicated in using through history. So, we have to understand the two projections' characteristics and differences. In this study, we would find out a fact that the maximum difference occurred in longitude and latitude is about 15cm at the Korean peninsular. This shift is accepted as proper in GIS and cartographic application but should be considered carefully in converting of the geodetic control point coordinates.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.321-331
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• 2011

The present work is aimed to analyze the creep characteristics of a turbojet engine turbine blade using the theta projection method. The theta projection method has been widely used due to its advantages and flexibility. For the creep characteristic analysis of the turbine blade, tests are performed considering the operating conditions and the non-linear material properties. Results from the creep test are fitted using the four theta model. The predicted proprieties using the four theta model are compared with the prediction model and creep test results. To obtain an optimum value of the four theta parameters in non-linear square method, a number of computing processes in the non-linear least square method were carried out to obtain full creep curves. Results using the theta model has more than 0.95 value of $R^2$. The results between the experimental values and predicted four theta model has about 90.0% accuracy. The theta projection method can be utilized for a design purpose to predict the creep behavior.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.2
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• pp.101-107
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• 1985

The coordinates of triangulation stations which has been used in Korea, were computed by means of the Gauss Conformal Double Projection in the 1910's. This projection has been considered as a problem in respect of accuracy, because the farther a station is from the origin, the larger the computational error becomes. In this paper, the Gauss Conformal Double Projection is compared with the T.M(Transverse Metcator) Projection which is widely used in many countries. In T.M projection method more accurate ground coordinates are obtained. This paper has an objective to improve the accuracy of public surveying by using the method presented in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1485-1492
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• 2015

This paper proposes a double frequency method using FTP(Fourier Transform Profilometry) in fringe projection techniques for 3D measurement systems. In fringe projection techniques, fringe pattern images are projected and captured, and then object is measured by analysing phase. PMP(Phase Measuring Profilometry) for analysing phase provides high-resolution and is robust to object's reflection and background intensities. However, the measurement range is narrow due to 2π ambiguity. In order to overcome this problem, a double frequency method is often used. This method can widen the range of measurement while maintaining the high-resolution, but the measurement time is taken about twice due to grab 2 times number of images. The proposed double frequency method using FTP requires an additional image for resolving 2π ambiguity. The proposed method effectively reduces the measurement time while maintaining the same accuracy.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.27-33
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• 2006

This paper presents a new approach to translation and rotation invariant feature extraction for image texture retrieval. For the rotation invariant feature extraction, we invent angular projection along angular frequency in Polar coordinate system. The translation and rotation invariant feature vector for representing texture images is constructed by the averaged magnitude and the standard deviations of the magnitude of the Fourier transform spectrum obtained by the proposed angular projection. In order to easily implement the angular projection, the Radon transform is employed to obtain the Fourier transform spectrum of images in the Polar coordinate system. Then, angular projection is applied to extract the feature vector. We present our experimental results to show the robustness against the image rotation and the discriminatory capability for different texture images using MPEG-7 data set. Our Experiment result shows that the proposed rotation and translation invariant feature vector is effective in retrieval performance for the texture images with homogeneity, isotropy and local directionality.

• Journal of the Korea Computer Graphics Society
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• v.27 no.4
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• pp.11-24
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• 2021

In this paper, we propose an artificial neural network framework that can represent the foam effects expressed in liquid simulation in detail without noise. The position and advection of foam particles are calculated using the existing screen projection method, and the noise problem that appears in this process is solved through an proposed artificial neural network. The important thing in the screen projection approach is the projection map, but noise occurs in the projection map in the process of projecting momentum into the discretized screen space, and we efficiently solve this problem by using an artificial neural network-based denoising network. When the foam generating area is selected through the projection map, 2D is inversely transformed into 3D space to generate foam particles. We solve the existing denoising network problem in which small-scaled foam particles disappear. In addition, by integrating the proposed algorithm with the screen-space projection framework, all the advantages of this approach can be accommodated. As a result, it shows through various experiments whether it is possible to stably represent not only the clean foam effects but also the foam particles lost due to the denoising process.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.299-309
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• 1998

The national coordinate system is an essential component for a geographic/land information system, since it provides the spatial reference for expressing position information. The national mapping of Korea has been based on 3-different meridians on the Gauss-Schreiber projection in year 1910s, later this was changed to the Gauss-Kruger projection. Existing map coordinate systems maintaining the national land survey project on 1910s, have some structural shortcomings of unknown computational procedures and projection methods. In this paper, the problems of the map coordinates usage and of longitudes origin shift(10.405") and their solutions are investigated. Also, this study discusses the issues involved in choosing coordinate system for digital mapping and their applications as a basis for spatial data management. The foreign country's coordinate systems are reviewed and the elements to realize a new unified grid coordinate system is proposed. The Transverse Mercator projection with a central meridian of $127^\circ\;30'$, scale factor 0.9996, and GRS80 ellipsoid, is selected in Korean peninsula.sula.

• Journal of KIISE:Software and Applications
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• v.31 no.4
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• pp.498-504
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• 2004

This paper presents a new text classifier based on a feature projection technique. In feature projections, training documents are represented as the projections on each feature. A classification process is based on individual feature projections. The final classification is determined by the sum from the individual classification of each feature. In our experiments, the proposed classifier showed high performance. Especially, it have fast execution speed and robustness with noisy data in comparison with k-NN and SVM, which are among the state-of-art text classifiers. Since the algorithm of the proposed classifier is very simple, its implementation and training process can be done very simply. Therefore, it can be a useful classifier in text classification tasks which need fast execution speed, robustness, and high performance.