• Title/Summary/Keyword: (affine) development

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GENERALIZED AFFINE DEVELOPMENTS

  • Park, Joon-Sik
    • Journal of the Chungcheong Mathematical Society
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    • v.28 no.1
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    • pp.65-72
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    • 2015
  • The (affine) development of a smooth curve in a smooth manifold M with respect to an arbitrarily given affine connection in the bundle of affine frames over M is well known (cf. S.Kobayashi and K.Nomizu, Foundations of Differential Geometry, Vol.1). In this paper, we get the generalized affine development of a smooth curve $x_t$ ($t{\in}[0,1]$) in M into the affine tangent space at $x_0$ (${\in}M$) with respect to a given generalized affine connection in the bundle of affine frames over M.

New Parametric Affine Modeling and Control for Skid-to-Turn Missiles (STT(Skid-to-Turn)미사일의 매개변수화 어파인 모델링 및 제어)

  • Chwa, Dong-Kyoung;Park, Jin-Young;Kim, Jinho;Song, Chan-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.8
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    • pp.727-731
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    • 2000
  • This paper presents a new practical autopilot design approach to acceleration control for tail-controlled STT(Skid-to-Turn) missiles. The approach is novel in that the proposed parametric affine missile model adopts acceleration as th controlled output and considers the couplings between the forces as well as the moments and control fin deflections. The aerodynamic coefficients in the proposed model are expressed in a closed form with fittable parameters over the whole operating range. The parameters are fitted from aerodynamic coefficient look-up tables by the function approximation technique which is based on the combination of local parametric models through curve fitting using the corresponding influence functions. In this paper in order to employ the results of parametric affine modeling in the autopilot controller design we derived a parametric affine missile model and designed a feedback linearizing controller for the obtained model. Stability analysis for the overall closed loop sys-tem is provided considering the uncertainties arising from approximation errors. the validity of the proposed modeling and control approach is demonstrated through simulations for an STT missile.

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Geocoding of Low Altitude UAV Imagery using Affine Transformation Model (부등각사상변환을 이용한 저고도 UAV 영상의 지형보정)

  • Kim, Seong-Sam;Jung, Jae-Hoon;Kim, Eui-Myoung;Yoo, Hwan-Hee;Sohn, Hong-Gyoo
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.4
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    • pp.79-87
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    • 2008
  • There has been a strong demand for low altitude UAV development in rapid mapping not only to acquire high resolution image with much more low cost and weather independent, compared to satellite surveying or traditional aerial surveying, but also to meet many needs of the aerial photogrammetry. Especially, efficient geocoding of UAV imagery is the key issue. Contrary to high UAV potential for civilian applications, the technology development in photogrammetry for example direct georeferencing is in the early stage and it requires further research and additional technical development. In this study, two approaches are supposed for automatic geocoding of UAV still images by simple affine transformation and block adjustment of affine transformation using minimal ground control points and also evaluated the applicability and quality of geometric model compared to geocoded images generated by commercial S/W.

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Molecular phylogenetic relationships within the PSP producing marine dinoflagellate, genus Alexandrium

  • Kim, Choong-jae;Kim, Sook-Yang;Kim, Kui-Young;Kang, Young-Sil;Kim, Hak-Gyoon;Kim, Chang-Hoon
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2003.10a
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    • pp.136-137
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    • 2003
  • The marine dinoflagellate genus Alexandrium has been recognized as the most representative toxic phytoplankton on account of production of paralytic shellfish poisoning (PSP) throughout the world. PSP producers, generally A, tamarense and A. catenella, within the genus Alexandrium have caused high level intoxicauon of fisheries products and even death of human. In addition, more recent increasing of geographical range of this deleterious species has given rise to alarming tension. The study presented here aimed construction of the molecular phylogenetic relationships through sequences-determination from 16 morphotypic species (containing newly sequenced 3 morphotypic species, A. tamiyavainchii, A. fraterculus and A. pseudogonyaulax) in LSU rDNA D1-D2 and 12 morphotypic species (containing newly sequenced 6 - morphotypic species, A. catenella, A. tamiyavanichii, A. fraterculus, A. affine, A. insuetum and A. pseudogonyaulax) in SSU rDNA region, and the sequences were subjected to comparative-analysis in respect to regional population using functionally expressed rDNA genus and pseudogenes. And we discussed on genetic differentiation between A. tamarense and A. catenella together with putative PSP divegence of the genus Alexandrium. The results of phylogenetic analysis showed the robust monophyletic 14 distinct classes of A. tamarense, A. excavatum, A. catenella, Tasmanian A. tamarense, A. affine (and/or A. concavum), Thai A. tamarense, A. tamiyavanichii, A. fraterculus, A. margalefii, A. andersonii, A. ostenfeldii, A. minutum (and/or A. lusitanicum), A. insuetum, and A, pseudogonyaulx clade. A. fraterculus and A. tamiyavanichii were sister relationship and they were positioned independently between A, affine cluster and those of A. margalefi, A. andersonii, A. ostenfeldii, A. minutum and A. insuetum. A. pseudogonyaulax appeared to be an ancestral taxon among Alexandrium.

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Image Registration Improvement Based-on FFT Techniques with the Affine Transform Estimation

  • Wisetphanichkij, Sompong;Pasomkusolsil, Sanchaiya;Dejhan, Kobchai;Cheevasuvit, Fusak;Mitatha, Somsak;Sra-Ium, Napat;Vorrawat, Vinai;Pienvijarnpong, Chanchai
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.260-262
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    • 2003
  • New Image registration techniques are developed for determining geometric distortions between two images of the same scene. First, the properties of the Fourier transform of a two dimensional function under the affine transformation are given. As a result, techniques for the estimation of the coefficients of the distortion model using the spectral frequency information are developed. Image registration can be achieved by applying the fast Fourier transform (FFT) technique for cross correlation of misregistered imagery to determine spatial distances. The correlation results may be rather broad, making detection of the peak difficult, what can be suppressed by enhancing cross-correlation technique. Yield greatly improves the delectability and high precision of image misregistration.

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A study on the development of the fin-tube heat exchanger pollution ratio evaluation algorithm using Image Processing and Affine Transformation (영상처리 및 어파인변환을 이용한 핀튜브 열교환기 오염율 평가 알고리즘 개발에 관한 연구)

  • Park, Sungmin;Jung, Myungin;Whang, Kwangil;Cho, Gyeongrae
    • Journal of the Korean Society of Visualization
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    • v.20 no.1
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    • pp.11-17
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    • 2022
  • Among the various factors that cause the performance decrease of heat exchangers used in many industries, flow path blocking is one of the important and serious factor. In order to solve this problem, proper maintenance and management of the heat exchanger is important and emphasized. In this study, we developed and algorithm that can quantitatively determine and diagnose the normal and blocked areas of fin-tube heat exchanger using pattern analysis, Gaussian Edge Detection, Image Processing and Affine Transformation techniques. The developed algorithms was applied to the actual heat exchanger and the performance was evaluated by comparing with the manual results. From these results, it was proved that the developed algorithm is effective in evaluating the pollution ratio of the fin-tube heat exchanger.

A New Functional Synthesis Method for Macro Quantum Circuits Realized in Affine-Controlled NCV-Gates (의사-제어된 NCV 게이트로 실현된 매크로 양자회로의 새로운 함수 합성법)

  • Park, Dong-Young;Jeong, Yeon-Man
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.4
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    • pp.447-454
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    • 2014
  • Recently most of functional synthesis methods for quantum circuit realization have a tendency to adopt the declarative functional expression more suitable for computer algorithms, so it's difficult to analysis synthesized quantum functions. This paper presents a new functional representation of quantum circuits compatible with simple architecture and intuitive thinking. The proposal of this paper is a new functional synthesis development by using the control functions as the power of corresponding to affine-controlled quantum gates based on the mathematical substitution of serial-product matrix operation over the target line for the arithmetic and modulo-2 ones between power functions of unitary operators. The functional synthesis algorithm proposed in this paper is useful for the functional expressions and synthesis using both of reversible and irreversible affine-controlled NCV-quantum gates.

Improved Image Matching Method Based on Affine Transformation Using Nadir and Oblique-Looking Drone Imagery

  • Jang, Hyo Seon;Kim, Sang Kyun;Lee, Ji Sang;Yoo, Su Hong;Hong, Seung Hwan;Kim, Mi Kyeong;Sohn, Hong Gyoo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.5
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    • pp.477-486
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    • 2020
  • Drone has been widely used for many applications ranging from amateur and leisure to professionals to get fast and accurate 3-D information of the surface of the interest. Most of commercial softwares developed for this purpose are performing automatic matching based on SIFT (Scale Invariant Feature Transform) or SURF (Speeded-Up Robust Features) using nadir-looking stereo image sets. Since, there are some situations where not only nadir and nadir-looking matching, but also nadir and oblique-looking matching is needed, the existing software for the latter case could not get good results. In this study, a matching experiment was performed to utilize images with differences in geometry. Nadir and oblique-looking images were acquired through drone for a total of 2 times. SIFT, SURF, which are feature point-based, and IMAS (Image Matching by Affine Simulation) matching techniques based on affine transformation were applied. The experiment was classified according to the identity of the geometry, and the presence or absence of a building was considered. Images with the same geometry could be matched through three matching techniques. However, for image sets with different geometry, only the IMAS method was successful with and without building areas. It was found that when performing matching for use of images with different geometry, the affine transformation-based matching technique should be applied.

Coastal Algal Blooms Caused by the Cyst-Forming Dinoflagellates (휴안포자(Cyst)를 형성하는 과편모조류에 의한 적조발생)

  • KIM Hak-Gyoon;PARK Joo-Suck;LEE Sam-Geun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.6
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    • pp.468-474
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    • 1990
  • Eight species, 6 Dinophyceae and 2 Raphidophyceae, caused a bloom in the southeastern coastal waters mainly in Chinhae Bay in Korea from March to September since 1982. Scrippsiella trochoidea and Heterocapsa triquetra bloomed in March then ensued a vernal species Heterosigma akashiwo. And Cochlodinium sp. and Alexandrium affine were occurred as causative organism in fall next to the estival dinoflagellates Gyrodinium instriatum and Pheopolykrikos hartmannii. Among them, spatio-temporal similarity of outbreak was significant in Heterosigma akashiwo since 1983, and a bit apparent for Cochlodinium sp.. The density was in the level from $10^3\;to\;10^5\;cells/ml$ and was dependent on the cell size rather than environmental characteristics.

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Development Robust Video Stabilization algorithm based Opticla Flow (Optical flow를 이용한 영상의 흔들림 보정 알고리듬 개발)

  • Cho, Gyeong-Rae;Doh, Deog-Hee;Kim, Hong-Yeob;Jin, Gwang-Ja;Kim, Do-Hyun
    • Journal of the Korean Society of Visualization
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    • v.17 no.3
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    • pp.66-69
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    • 2019
  • An image compensating algorithm with high-vibration movement is proposed, using optical flow and the Kalman Filter. The temporal motion vector field is calculated by Optical flow and suspicious vectors are removed or adjusted by the Gaussian interpolation method. The high-vibrated vector filled is stabilized by the Kalman filter. Lastly, compensated images are obtained by affine transformation. This proposed algorithm gives good compensated video images on high-vibration situations.