• 제목/요약/키워드: recurrent space

검색결과 125건 처리시간 0.025초

THE INDUCED AND INTRINSIC CONNECTIONS OF BERWALD TYPE IN A FINSLERIAN HYPERSURFACE

  • Ha Yong Park;Hong Suh Park
    • 대한수학회논문집
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    • 제12권2호
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    • pp.383-391
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    • 1997
  • The main purpose of the present paper is to derive the induced (Finsler) connections on the hypersurface from the Finsler connections of Berwald type (a Berwald h-recurrent connection and a $F\Gamma$' connection) of a Finsler space and to seek the necessary and sufficient conditions that the induced connections coincide with the intrinsic connections. And we show the quantities and relations with respect to the respective induced connections. Finally we show some examples.

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ON THE "TERRA INCOGNITA" FOR THE NEWTON-KANTROVICH METHOD WITH APPLICATIONS

  • Argyros, Ioannis Konstantinos;Cho, Yeol Je;George, Santhosh
    • 대한수학회지
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    • 제51권2호
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    • pp.251-266
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    • 2014
  • In this paper, we use Newton's method to approximate a locally unique solution of an equation in Banach spaces and introduce recurrent functions to provide a weaker semilocal convergence analysis for Newton's method than before [1]-[13], in some interesting cases, provided that the Fr$\acute{e}$chet-derivative of the operator involved is p-H$\ddot{o}$lder continuous (p${\in}$(0, 1]). Numerical examples involving two boundary value problems are also provided.

카오틱 신경망을 이용한 로봇 매니퓰레이터용 토크보상제어기의 설계 (Design of Torque Compensatory Controller for Robot Manipulator using Chaotic Neural Networks)

  • 문찬;김상희;박원우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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    • pp.530-532
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    • 1998
  • In this paper, We Designed the torque compensatory controller for robot manipulator using modified chaotic neural networks with self feedback loop. The proposed torque compensatory controller compensate torque of the PD controller. In order to estimate the proposed controller, we implemented to the Cartesian space control of three-axis PUMA robot and compared the simulation results with recurrent neural networks(RNNs) controller. Simulation results show that the learning error drastically decrease at on-line learning. The proposed CNNs controller shows much better control performance and shorter processing time compared to the recurrent neural network controller in the robot trajectory control.

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AVERAGE SHADOWING PROPERTIES ON COMPACT METRIC SPACES

  • Park Jong-Jin;Zhang Yong
    • 대한수학회논문집
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    • 제21권2호
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    • pp.355-361
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    • 2006
  • We prove that if a continuous surjective map f on a compact metric space X has the average shadowing property, then every point x is chain recurrent. We also show that if a homeomorphism f has more than two fixed points on $S^1$, then f does not satisfy the average shadowing property. Moreover, we construct a homeomorphism on a circle which satisfies the shadowing property but not the average shadowing property. This shows that the converse of the theorem 1.1 in [6] is not true.

THE STRUCTURE OF ALMOST REGULAR SEMIGROUPS

  • Chae, Younki;Lim, Yongdo
    • 대한수학회보
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    • 제31권2호
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    • pp.187-192
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    • 1994
  • The author extended the small properties of topological semilattices to that of regular semigroups [3]. In this paper, it could be shown that a semigroup S is almost regular if and only if over bar RL = over bar R.cap.L for every right ideal R and every left ideal L of S. Moreover, it has shown that the Bohr compactification of an almost regular semigroup is regular. Throughout, a semigroup will mean a topological semigroup which is a Hausdorff space together with a continuous associative multiplication. For a semigroup S, we denote E(S) by the set of all idempotents of S. An element x of a semigroup S is called regular if and only if x .mem. xSx. A semigroup S is termed regular if every element of S is regular. If x .mem. S is regular, then there exists an element y .mem S such that x xyx and y = yxy (y is called an inverse of x) If y is an inverse of x, then xy and yx are both idempotents but are not always equal. A semigroup S is termed recurrent( or almost pointwise periodic) at x .mem. S if and only if for any open set U about x, there is an integer p > 1 such that x$^{p}$ .mem.U.S is said to be recurrent (or almost periodic) if and only if S is recurrent at every x .mem. S. It is known that if x .mem. S is recurrent and .GAMMA.(x)=over bar {x,x$^{2}$,..,} is compact, then .GAMMA.(x) is a subgroup of S and hence x is a regular element of S.

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자동문서분류를 위한 텐서공간모델 기반 심층 신경망 (A Tensor Space Model based Deep Neural Network for Automated Text Classification)

  • 임푸름;김한준
    • 데이타베이스연구회지:데이타베이스연구
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    • 제34권3호
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    • pp.3-13
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    • 2018
  • 자동문서분류(Text Classification)는 주어진 텍스트 문서를 이에 적합한 카테고리로 분류하는 텍스트 마이닝 기술 중의 하나로서 스팸메일 탐지, 뉴스분류, 자동응답, 감성분석, 쳇봇 등 다양한 분야에 활용되고 있다. 일반적으로 자동문서분류 시스템은 기계학습 알고리즘을 활용하며, 이 중에서 텍스트 데이터에 적합한 알고리즘인 나이브베이즈(Naive Bayes), 지지벡터머신(Support Vector Machine) 등이 합리적 수준의 성능을 보이는 것으로 알려져 있다. 최근 딥러닝 기술의 발전에 따라 자동문서분류 시스템의 성능을 개선하기 위해 순환신경망(Recurrent Neural Network)과 콘볼루션 신경망(Convolutional Neural Network)을 적용하는 연구가 소개되고 있다. 그러나 이러한 최신 기법들이 아직 완벽한 수준의 문서분류에는 미치지 못하고 있다. 본 논문은 그 이유가 텍스트 데이터가 단어 차원 중심의 벡터로 표현되어 텍스트에 내재한 의미 정보를 훼손하는데 주목하고, 선행 연구에서 그 효능이 검증된 시멘틱 텐서공간모델에 기반하여 심층 신경망 아키텍처를 제안하고 이를 활용한 문서분류기의 성능이 대폭 상승함을 보인다.

순환인공신경망을 활용한 터널굴착면 전방 Q값 예측에 관한 연구 (Study on Q-value prediction ahead of tunnel excavation face using recurrent neural network)

  • 홍창호;김진;류희환;조계춘
    • 한국터널지하공간학회 논문집
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    • 제22권3호
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    • pp.239-248
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    • 2020
  • 터널 굴착 시 정확한 암반 분류는 적합한 지보패턴을 설치하는 데 도움을 준다. 암반의 분류를 위해 주로 RMR (Rock Mass Ration)과 Q값을 산정하여 수행되며, 페이스 매핑(face mapping)을 바탕으로 산정된다. 점보드릴 및 프로브드릴의 기계 데이터을 활용하거나 딥러닝을 활용한 굴착면 사진 분석 등의 방법이 암반등급 분류를 예측하기 위해 사용되고 있으나, 분석 시 오랜 시간이 소요되거나, 굴착면 전방의 암반등급을 파악할 수 없다는 점에서 한계를 갖는다. 본 연구에서는 순환인공신경망(Recurrent neural network, RNN)을 활용하여 굴착면 전방의 Q값을 예측하는 방법을 개발하였고 페이스 매핑으로부터 획득한 Q값과 비교/검증하였다. 4,600여개의 굴착면 데이터 중 70%를 학습에 활용하였고, 나머지 30%는 검증에 사용하였다. 학습의 횟수와 학습에 활용한 이전굴착면의 개수를 변경하여 학습을 수행하였다. 예측된 Q값과 실제 Q값의 유사도는 RMSE (root mean square error)를 기준으로 비교하였다. 현재 굴착면과 바로 직전의 굴착면의 Q값을 활용하여 600회 학습하여 예측한 Q값의 RMSE값이 가장 작은 것을 확인하였다. 본 연구의 결과는 학습에 사용한 데이터 값 등이 변화하는 경우 변화할 수 있으나 터널에서의 이전 지반상태가 앞으로의 지반상태에 영향을 미치는 시스템을 이해하고, 이를 통해 터널 굴착면 전방의 Q값의 예측이 가능할 것으로 판단된다.

Diagnostic and management challenge of concurrent tongue squamous cell carcinoma with an unknown parapharyngeal mass

  • Raymond Shupak;Roderick Kim;Jun Hyuk Huh
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제50권1호
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    • pp.56-59
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    • 2024
  • There are very few case reports of the diagnosis and management of concurrent oral cavity and parapharyngeal space tumors. We present a case involving a 49-year-old female who presented with oral cavity squamous cell carcinoma confirmed by biopsy. Initial diagnostic workup revealed a concurrent parapharyngeal mass. Diagnostic studies and surgical therapy were tailored to account for both pathological entities. The patient was treated with a combination of surgery and adjuvant therapy. The surgical strategy was designed to address both lesions simultaneously. One year post-surgery, the patient had good response to therapy with no evidence of persistent or recurrent disease. This report discusses the outcome and treatment of a rare case of concurrent squamous cell carcinoma with a complicating parapharyngeal space tumor. It explores the diagnostic process, comprehensive workup, and the surgical management.

NONWANDERING POINTS OF A MAP ON THE CIRCLE

  • Bae, Jong-Sook;Cho, Seong-Hoon;Min, Kyung-Jin;Yang, Seung-Kab
    • 대한수학회지
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    • 제33권4호
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    • pp.1115-1122
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    • 1996
  • In study of the dynamics of a map f from a topological space X to itself, a central role is played by the various recursive properties of the points of X. One such property is periodicity. A weaker property is that of being nonwandering. Intermediate recursive properties include almost periodicity and recurrence.

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CHARACTERIZATIONS ON CHAIN RECURRENCES

  • Park, Jong-Suh;Ku, Se-Hyun
    • 대한수학회보
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    • 제47권2호
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    • pp.287-293
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    • 2010
  • It is well known that there is a residual subset J of the space of $C^1$-diffeomorphisms on a compact Riemannian manifold M such that the maps f $\mapsto$ chain recurrent set of f and f $\mapsto$ number of chain components of f are continuous on J. In this paper we get the flow version of the above results on diffeomorphisms.