• 제목/요약/키워드: affine

검색결과 605건 처리시간 0.027초

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

  • 좌동경;최진영;김진호;송찬호
    • 제어로봇시스템학회논문지
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    • 제6권8호
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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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In Vitro Mycorrhization and Morphological Characterization of Xanthoconium affine with Pinus densiflora

  • Wang, Eun-Jin;Jang, Yeongseon;Ka, Kang-Hyeon
    • 한국균학회지
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    • 제45권4호
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    • pp.319-327
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    • 2017
  • In this study, we investigated the culture conditions of four ectomycorrhizal fungi, namely, Amanita spissacea NIFoS 2719, Pisolithus arhizus NIFoS 2784, Suillus spraguei NIFoS 2848, and Xanthoconium affine NIFoS 2716, in solid and liquid culture media. In addition, we attempted to induce in vitro mycorrhization of the fungi with Pinus densiflora. Prior to liquid culture, we determined the optimal culture conditions for each species in solid media. The results revealed that all species examined are capable of growth in potato dextrose agar (PDA), malt extract agar (MEA), and modified Melin-Norkran's medium (MMN), although their preferred growth media were different. Liquid culture experiments showed that inorganic nitrogen did not enhance the mycelial growth of all four species. Therefore, we used MMN-based liquid inocula to promote the growth of ectomycorrhizal fungi in our symbiosis culture system. Mycorrhization was observed in Xanthoconium affine NIFoS 2716. Morphological analysis revealed that fungi-inoculated roots of P. densiflora form simple and dichotomous lateral roots with dense mycelia. In addition, inoculation with X. affine NIFoS 2716 promoted root and shoot developments.

A New Shape Adaptation Scheme to Affine Invariant Detector

  • Liu, Congxin;Yang, Jie;Zhou, Yue;Feng, Deying
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제4권6호
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    • pp.1253-1272
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    • 2010
  • In this paper, we propose a new affine shape adaptation scheme for the affine invariant feature detector, in which the convergence stability is still an opening problem. This paper examines the relation between the integration scale matrix of next iteration and the current second moment matrix and finds that the convergence stability of the method can be improved by adjusting the relation between the two matrices instead of keeping them always proportional as proposed by previous methods. By estimating and updating the shape of the integration kernel and differentiation kernel in each iteration based on the anisotropy of the current second moment matrix, we propose a coarse-to-fine affine shape adaptation scheme which is able to adjust the pace of convergence and enable the process to converge smoothly. The feature matching experiments demonstrate that the proposed approach obtains an improvement in convergence ratio and repeatability compared with the current schemes with relatively fixed integration kernel.

항공사진을 이용한 장기해안선변화 조사 (Investigation of Long-Term Shoreline Changes Using Aerial Images)

  • 정승진;김규한;편종근
    • 한국해안해양공학회지
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    • 제16권1호
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    • pp.10-17
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    • 2004
  • 지본 연구에서는 장기해안선변화를 조사, 해석함에 있어서 정사사진해석에 비해 비교적 손쉬운 affine 변환 해석방법을 이용하여 항공사진 자료를 분석하고, 정확도 평가를 수행하였다. 검토결과, 대상해안은 과거에 비해 해안선이 현저히 후퇴하여 침식되고 있음을 확인할 수 있었다. 또한, 정확도 평가 분석에서 나타난 RMS 오차는 1∼2m 미만의 오차에 불과하다는 것이 확인되었다. 항공사진측량작업내규에서 제시하는 최대허용오차범위가 2m인 점을 감안한다면, 본 연구에서 도출된 해안선변화 분석결과는 신뢰성이 높은 것이라 사료된다.

가변 스텝사이즈를 이용한 부밴드 인접투사 알고리즘 (Subband Affine Projection Algorithm Using Variable Step Size)

  • 최훈;배현덕
    • 한국음향학회지
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    • 제26권2호
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    • pp.69-74
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    • 2007
  • 입력신호의 상관도가 높은 신호처리 응용에서 부밴드 인접투사(Subband Affine Projection: SAP) 알고리즘과 스텝사이즈 조정은 LMS형(Least Mean Square-type) 알고리즘이 갖는 느린 수렴속도와 큰 정상상태오차를 개선할 수 있는 좋은 해결책이다. 본 논문은 가변 스텝사이즈를 사용하는 부밴드 인접투사 알고리즘을 제안한다. 제안한 방법은 부밴드 구조의 인접투사 알고리즘과 스텝사이즈 조정을 결합함으로써 적은 계산량으로 빠른 수렴속도와 작은 정상상태오차를 얻을 수 있다. 높은 상관도를 갖는 입력신호에 대한 실험을 통해 제안한 방법이 기존 방법에 비해 우수함을 보인다.

파라미터 불확실성을 갖는 어핀 T-S 퍼지 시스템의 제어기 설계 (Controller Design for Affine T-S Fuzzy System with Parametric Uncertainties)

  • Lee, Sang-In;Park, Jin-Bae;Joo, Young-Hoon
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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    • pp.133-136
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    • 2004
  • This paper proposes a stability condition in affine Takagi-Sugeno (T-S) fuzzy systems with parametric uncertainties and then, introduces the design method of a fuzzy-model-based controller which guarantees the stability. The analysis is based on Lyapunov functions that are continuous and piecewise quadratic. The search for a piecewise quadratic Lyapunov function can be represented in terms of linear matrix inequalities (LMIs).

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NONDEGENERATE AFFINE HOMOGENEOUS DOMAIN OVER A GRAPH

  • Choi, Yun-Cherl
    • 대한수학회지
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    • 제43권6호
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    • pp.1301-1324
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    • 2006
  • The affine homogeneous hypersurface in ${\mathbb{R}}^{n+1}$, which is a graph of a function $F:{\mathbb{R}}^n{\rightarrow}{\mathbb{R}}$ with |det DdF|=1, corresponds to a complete unimodular left symmetric algebra with a nondegenerate Hessian type inner product. We will investigate the condition for the domain over the homogeneous hypersurface to be homogeneous through an extension of the complete unimodular left symmetric algebra, which is called the graph extension.

ON THE CONSTRUCTION OF PSEUDO-FINSLER EIKONAL EQUATIONS

  • Cimdiker, Muradiye;Ekici, Cumali
    • 호남수학학술지
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    • 제42권1호
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    • pp.75-91
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    • 2020
  • In this study, we have generalized pseudo-Finsler map by introducing the concept of semi-Riemannian map and have found pseudo-Finsler eikonal equations using pseudo-Finsler map. After that, we have obtained some sufficient theorems on pseudo-Finsler manifolds for the existence of solutions to the eikonal equation. At the same time, we have introduced a natural definition for the affine maps between pseudo-Finsler manifolds and have reached the affine solutions of them.

DIFFERENTIABILITY OF QUASI-HOMOGENEOUS CONVEX AFFINE DOMAINS

  • JO KYEONGHEE
    • 대한수학회지
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    • 제42권3호
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    • pp.485-498
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    • 2005
  • In this article we show that every quasi-homogeneous convex affine domain whose boundary is everywhere differentiable except possibly at a finite number of points is either homogeneous or covers a compact affine manifold. Actually we show that such a domain must be a non-elliptic strictly convex cone if it is not homogeneous.