• 호남수학학술지
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• 제26권4호
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• pp.483-507
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• 2004

In this paper the left regular representation and the reduced $C^*$-algebra for a commutative separative semigroup is defined. The universal representation, the reduced $C^*$-algebra and the full $C^*$-algebra for the additive semigroup $N^+$ are given. Also it is proved that $C*_r(N^+){\ncong}C^*(N^+)$.

• East Asian mathematical journal
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• 제21권2호
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• pp.151-161
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• 2005

We analyze the structure of $C^*-algebras$ generated by left regular isometric representations of semigroups.

• Korean Journal of Mathematics
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• 제17권1호
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• pp.25-36
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• 2009

We compute spectrums of left regular isometries and weighted left regular isometries of a strongly perforated semigroup $P=\{0,2,3,4,{\cdots}\}$.

• 대한수학회논문집
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• 제21권1호
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• pp.17-25
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• 2006

In this paper, we study the right regular representation $R_\Gamma$ of a finite group G on the vector space consisting of vector valued functions on ${\Gamma}/G$ with a subgroup r of G and give a trace formula using the work of M. -F. Vigneras.

• 한국수학교육학회지시리즈A:수학교육
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• 제48권3호
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• pp.303-328
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• 2009

In this study, we developed the teaching methods using manipulative materials to teach regular polytopes, and applied these to first-year student of middle school who is attending the extra math class. In that class, we focused on the change of the mathematical representations -especially verval, visual and symbolic representations- and mathematical behavioral. By analyzing characterstics the students' work sheets, we obtained affirmative results as follows. First, manipulative materials played an important role on drawing a development figure of regular polyhtopes describing the verval representation definition of regular polytopes. Second, classes utilizing manipulative materials changed students verbalism level of representations the definition of regular polytopes. For example, in the first class about 60% of students are in the $0{\sim}2$ vervalism level, but in the third class, about 65% of students are in the $6{\sim}7$ level. Third, classes utilizing manipulative materials improved visual representation about development figure. After experiences making several development figures about regular octahedron directly, and discussion, students found out key points to be considered for draws development figure and this helped to draw development figures about other regular polytopes. Fourth, students were unaccustomed to make symbolic representations of regular polytopes. But, they obtained same improvement in symbolic representations, so in fifth the class some students try to make symbol about something in common of whole regular polytopes. Fifth, after the classes, we have significant differences in the students, especially behavioral characteristics in II items such as mind that want to study own fitness, interest, attachment, spirit of inquiry, continuously mathematics posthumously. This means that classes using manipulative materials. Specially, 'mind that want to study mathematics continuously' showed the biggest difference, and it may give positive influence to inculcates mathematics studying volition while suitable practical use of manipulative materials. To conclude, classes using manipulative materials may help students enhance the verbal, visual representation, and gestates symbol representation. Also, the class using manipulative materials may give positive influence in some part of mathematical behavioral characteristic. Therefore, if we use manipulative materials properly in the class, we have more positive effects on the students cognitive perspect and behavioral cteristics.

• Journal of the Korean Statistical Society
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• 제19권1호
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• pp.45-53
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• 1990

Factorization models are a generalization of hierarchical loglinear models which apply equally to discrete and continuous distributions. In regular (strictly positive) cases the intersection of two factorization models is another factorization model whose representation is obtained by a simple algorithm. Failure of this result in an irregular case is related to a theorem of Basu on ancillary statistics.

• 대한수학회보
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• 제54권2호
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• pp.583-592
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• 2017

The paper gives the regularity of dual quaternionic functions and the dual Cauchy-Riemann system in dual quaternions. Also, the paper researches the polar representation and properties of a dual quaternionic function and their regular quaternionic functions.

• 디지털융복합연구
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• 제14권6호
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• pp.535-546
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• 2016

철자지식과 음운인식이 시각적 단어 해독과 부호화에 미치는 영향을 알아보기 위하여, 5세에서 8세의 아동 각 15명씩 총 60명을 대상으로 철자지식(자모지식, 소리-글자 대응지식, 철자표상), 음운인식(단어인식, 음절인식, 음소인식), 시각적 단어 해독(자소-음소 일치 단어 읽기, 불일치 단어 읽기), 시각적 단어 부호화(자소-음소 일치 단어 받아쓰기, 불일치 단어 받아쓰기) 과제를 실시하였다. 그 결과 철자지식, 음운인식, 시각적 단어 해독, 시각적 단어 부호화의 모든 과제에서 연령 집단 간 수행력 차이가 유의하였고, 각 과제 수행력 간 유의한 정적 상관관계가 있었다. 이 중 불일치 단어 철자표상, 음절인식, 음소인식이 본 연구 대상자들을 연령에 따라 보다 민감하게 구분하는 것으로 나타났다. 시각적 단어 해독과 부호화 능력을 예측하는 변인으로 음운인식보다는 자모지식과 철자표상과 같은 철자지식 능력이 포함되었다. 본 연구결과는 학령기 전후 철자에 보다 익숙해지면 음운인식보다 철자지식이 시각적 단어 해독과 부호화에 더 많은 영향을 미친다는 것을 시사한다.

• 대한조선학회지
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• 제20권3호
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• pp.17-20
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• 1983

There have been many investigations of predicting the added resistance of a ship in seaway since Havelock discussed this topic in 1937. Among these researches, Maruo's theoretical approach is known as the most consistent mathematical representation for added resistance of a ship in regular head sea. In his theory, the hull form of a ship is represented under the slender body approximation. But the motion responses which were used for the calculation of the added resistance have been obtained by using the strip method which is based on an approximation that the hull form may be expressed as set of two dimensional cylinder sections in longitudinal direction. Therefore two different methods for hull form representation were implicity used in Maruo's original work for the added resistance calculation. Utilizing the characteristics that hull forms are usually slender, Kan expressed the hull form as two dimensional cylinder at each station by using the Taylor series expansion for the length wise direction. Putting this idea into Maruo's original work, the added resistance can be obtained with the explicitly unique representation of the hull form. For the purpose of comparison the added resistance of a hull form(series 60, Cb=0.6) was calculated by using the motion response obtained by Shintani. The numerical result showes a good qualitative agreement with the experimental result by Sibul.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2006년도 춘계 학술대회 발표논문집
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• pp.113-116
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• 2006

This research was investigate to understand how moderate bilingual subjects represent the lexicon in second language. Although most researches have focused only on high proficient bilinguals, we analysed how moderate bilinguals who have learned English mostly in school represent the prototype of verb and its inflected form of verb. Results of lexical decision task showed that moderate bilingual subjects used different mental representation depending on whether the verb have regular or irregular conjugation. With regular verbs, the identification of an inflected form was affected by both the frequency of its prototype and that of inflected form, but with irregular verbs, it is affected only by the frequency of inflected form.