• 제목/요약/키워드: Completely regular

검색결과 98건 처리시간 0.038초

STRUCTURE OF IDEMPOTENTS IN RINGS WITHOUT IDENTITY

  • Kim, Nam Kyun;Lee, Yang;Seo, Yeonsook
    • 대한수학회지
    • /
    • 제51권4호
    • /
    • pp.751-771
    • /
    • 2014
  • We study the structure of idempotents in polynomial rings, power series rings, concentrating in the case of rings without identity. In the procedure we introduce right Insertion-of-Idempotents-Property (simply, right IIP) and right Idempotent-Reversible (simply, right IR) as generalizations of Abelian rings. It is proved that these two ring properties pass to power series rings and polynomial rings. It is also shown that ${\pi}$-regular rings are strongly ${\pi}$-regular when they are right IIP or right IR. Next the noncommutative right IR rings, right IIP rings, and Abelian rings of minimal order are completely determined up to isomorphism. These results lead to methods to construct such kinds of noncommutative rings appropriate for the situations occurred naturally in studying standard ring theoretic properties.

정점의 법선벡터를 이용한 기하이미지의 최적화 (Geometry Image Optimization using a Normal Vector)

  • 박종래;양성봉
    • 한국정보처리학회:학술대회논문집
    • /
    • 한국정보처리학회 2004년도 추계학술발표논문집(상)
    • /
    • pp.241-244
    • /
    • 2004
  • 일반적으로 메쉬(mesh)는 비정규 연결 형태(irregular connectivity)로 되어 있다. 리메싱(remeshing)은 비정규 연결 형태의 메쉬를 정규 연결 형태(regular connectivity)로 바꾸어 주는 작업이다. 메쉬의 기하 정보가 2D 그리드에 저장이 되어 있는 기하이미지(geometry Images)는 비정규 연결 형태의 메쉬를 완전 정규 형태(completely regular connectivity)로 리메싱하는 데 사용된다. 원본 메쉬를 기하 이미지로 생성하는 방법은 변형되는 크기를 최소화 하는 스트레치 메트릭(stretch metric)을 기반으로 이루어 졌다. 이 방법은 리메싱된 메쉬의 언더샘플링(undersampling)을 줄여 주게 된다. 하지만 리메싱 과정에서 생기는 오버샘플링(oversampling)은 줄여 주지 못한다. 본 논문에서는 정점(vertex)의 법선 벡터(normal vector)를 이용하여 기하이미지의 오버샘플링을 줄이는 방법을 제시한다.

  • PDF

QUASI $O-z$-SPACES

  • Kim, Chang-Il
    • 대한수학회보
    • /
    • 제30권1호
    • /
    • pp.117-124
    • /
    • 1993
  • In this paper, we introduce a concept of quasi $O_{z}$ -spaces which generalizes that of $O_{z}$ -spaces. Indeed, a completely regular space X is a quasi $O_{z}$ -space if for any regular closed set A in X, there is a zero-set Z in X with A = c $l_{x}$ (in $t_{x}$ (Z)). We then show that X is a quasi $O_{z}$ -space iff every open subset of X is $Z^{#}$-embedded and that X is a quasi $O_{z}$ -spaces are left fitting with respect to covering maps. Observing that a quasi $O_{z}$ -space is an extremally disconnected iff it is a cloz-space, the minimal extremally disconnected cover, basically disconnected cover, quasi F-cover, and cloz-cover of a quasi $O_{z}$ -space X are all equivalent. Finally it is shown that a compactification Y of a quasi $O_{z}$ -space X is again a quasi $O_{z}$ -space iff X is $Z^{#}$-embedded in Y. For the terminology, we refer to [6].[6].

  • PDF

일부지역 치위생 전공 학생들의 실습행태에 따른 개인방호 및 기구멸균에 관한 인식조사 (Research on Dental Hygienics Students' Perception of Personal Protection and Instrument Disinfection of by Practical Training Type in Some Areas)

  • 가경환;구인영;이명선;문선정
    • 보건의료산업학회지
    • /
    • 제7권3호
    • /
    • pp.193-202
    • /
    • 2013
  • This study aimed to investigate and compare the perception of personal protective equipments and instrument sterilization of students who are in attendance at colleges and universities and which have bedside training as a regular subject in their curriculum for third-year students. 'Completely True' is the highest response to the question about the importance of wearing gloves, mask and medical gown from all groups. 'Completely True' is the highest response to the question about the necessity for replacement of gloves from all groups. 'Moderate True' is the highest response to the question about the necessity for replacement of mask from the group without practical training and 'Completely True' is the highest response to the question about the importance of hair cleanliness from all groups regardless of practical training experience. For the question about the perception of instrument disinfection and sterilization, the group with inside and outside practical training showed the highest perception level. Consequently, the right education for prevention of infection by setting inclusive guidelines to enhance the level of perception and practice seems continuously necessary.

MORPHIC PROPERTY OF A QUOTIENT RING OVER POLYNOMIAL RING

  • Long, Kai;Wang, Qichuan;Feng, Lianggui
    • 대한수학회보
    • /
    • 제50권5호
    • /
    • pp.1433-1439
    • /
    • 2013
  • A ring R is called left morphic if $$R/Ra{\simeq_-}l(a)$$ for every $a{\in}R$. Equivalently, for every $a{\in}R$ there exists $b{\in}R$ such that $Ra=l(b)$ and $l(a)=Rb$. A ring R is called left quasi-morphic if there exist $b$ and $c$ in R such that $Ra=l(b)$ and $l(a)=Rc$ for every $a{\in}R$. A result of T.-K. Lee and Y. Zhou says that R is unit regular if and only if $$R[x]/(x^2){\simeq_-}R{\propto}R$$ is morphic. Motivated by this result, we investigate the morphic property of the ring $$S_n=^{def}R[x_1,x_2,{\cdots},x_n]/(\{x_ix_j\})$$, where $i,j{\in}\{1,2,{\cdots},n\}$. The morphic elements of $S_n$ are completely determined when R is strongly regular.

FUZZY TOPOLOGICAL ORDERED SPACES

  • In, Byung-Sik
    • Journal of applied mathematics & informatics
    • /
    • 제10권1_2호
    • /
    • pp.361-370
    • /
    • 2002
  • We are to present some properties of binary relations on fuzzy topological spares by means of categorical method. The concept of fuzzy topological ordered spaces was introduced by Katsaras[8]. In this paper we study some special categories, i.e, FTQOS, FTPOS, LSCQ, USCQ, SCQ, CQ, NQO, CRQO, associated with fuzzy topological spaces.

Geometric Reparametization of Regular Plane Polynomial Pythagorean Hodograph Curves

  • Kim, Gwang-II
    • 한국컴퓨터그래픽스학회논문지
    • /
    • 제7권1호
    • /
    • pp.19-25
    • /
    • 2001
  • 본 논문에서는 평면 다항식 피타고리안 호도그라프 곡선을 그 근들의 관점에서 특별한 기하학적 재 매개화하는 것에 관하여 연구한다. 피타고라스 호도그라프 곡선들은 그 호도그라프의 근들에 의하여 완전히 결정된다. 피타고라스 호도그라프 곡선들의 근들의 자취는 아주 흥미로운 기하학적 성질들을 만족함을 보인다.

  • PDF

ON THE WEAKLY COMPACT WEIGHTED OPERATORS ON $C_b(X)$

  • Lee, Joung-Nam
    • Journal of applied mathematics & informatics
    • /
    • 제14권1_2호
    • /
    • pp.423-427
    • /
    • 2004
  • For any completely regular Hausdorff space weighted operator on $C_{b}(X)$ is not necessarily compact. In this paper we find both necessary and sufficient conditions for a weighted operator on $C_{b}(X)$ to be compact. And known results in $uC_{\Phi}$ are shown to emerge as special cases.

분산성 램파의 전파에서 입력 파형의 복원을 위한 신호처리 (Signal Processing Techniques for Recovering Input Waveforms in Dispersive Lamb Wave Propagation)

  • 정현조;조성종
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
    • /
    • pp.694-695
    • /
    • 2013
  • An experimental study has been made with the use of time reversal concepts to recover the input waveform in a long range propagation of dispersive Lamb waves. Three techniques have been tested: Regular TR, 1 bit TR and Inverse filter (IF). The IF approach was found to completely recover the original input signal. Moreover, the IF technique significantly increases the contrast, i.e., the ratio of the recovered signal and the sideband signal.

  • PDF