• 한국수학사학회지
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• 제15권1호
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• pp.1-14
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• 2002

This paper treats the history of the fundament of projective geometry Especially we introduce the essence of the framework of Karl Chirstian von Staudt's ‘Geometrie der Lage’. Von Staudt used axiomatical method to bum the system of the projective geometry, and proved the fundamental theorem of projective geometry. And he handled imaginary elements (or the first time in synthetic projective geometry.

• 대한수학회지
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• 제35권4호
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• pp.855-867
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• 1998

In the present paper, we introduce the notions of quaternionically planar curves and quaternionically projective transformations to the case of almost quaternionic manifold with symmetric affine connection. Also, we obtain an invariant tensor field under the quaternionically projective transformation, and show that a quaternionic Kahlerian manifold with such a vanishing tensor field is of constant Q-sectional curvature.

• 대한수학회지
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• 제36권1호
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• pp.109-123
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• 1999

In this paper we prove a reduction theorem of the codimension for real submanifold of quaternionic projective space as a quaternionic analogue corresponding to those in Cecil [4], Erbacher [5] and Okumura [9], and apply the theorem to quaternionic CR- submanifold of quaternionic projective space.

• 호남수학학술지
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• 제35권4호
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• pp.747-755
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• 2013

This paper deals with the unit groups of the endomorphism rings of projective modules over polynomial rings and further over formal power series rings. A normal subgroup of the unit group is defined and discussed. The local splitting properties of element of endomorphism rings of projective modules over polynomial rings are given.

• 대한수학회지
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• 제40권2호
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• pp.273-286
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• 2003

Let $F^{\alpha}$G be a twisted group algebra. A subalgebra of $F^{\alpha}$G generated by all class sums of partition P of G is called a projective class algebra in $F^{alpha}$G associated with partition P. In this paper we study various partitions of G determined by actions of certain operator groups on G and construct projective class algebras depending on the actions. With regard to projective class algebras, we investigate structures of associated skew group algebras and fixed group algebras.

• East Asian mathematical journal
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• 제15권2호
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• pp.337-344
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• 1999

If any geodesic on $F^n$ is also a geodesic on $\={F}^n$ and the inverse is true, the change $\sigma:L{\rightarrow}\={L}$ of the metric is called projective. In this paper, we will find the condition that a recurrent Finsler space remains to be a recurrent one under the projective change.

• Kyungpook Mathematical Journal
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• 제1권1호
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• pp.1-15
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• 1958

• 문화기술의 융합
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• 제4권2호
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• pp.1-7
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• 2018

주거환경이 고령자 삶의 질을 결정하는 중요한 요인으로 인식되면서 고령자우울 측정의 필요성이 부각된다. 특히, 고령자 인지특성, 생활환경 등 다양한 변수를 고려하여 측정 도구를 개발하는 것은 정확한 심리 진단에 매우 중요한 일이다. 본 연구에서는, 2018년도 1월 22일부터 2월 2일까지 7개 시 구에 거주하는 65세 이상 남 여 단독가구 고령자 301명을 대상으로 주거환경 속에서 나타나는 우울을 투사적 이미지를 적용하여 측정하였다. 이를 위해 주거우울과 투사이미지의 상관관계를 규명하였고, 요인분석을 통해 투사이미지 기반 측정도구를 보완하였다. 고령자주거우울지수(GDDI)와 '투사이미지 기반 고령자주거우울지수'의 상관관계를 규명하였으며, 척도의 정확도를 분석하였다. 연구 결과, 투사이미지를 활용한 설문은 서술형 설문과 높은 상관관계를 갖고 있음을 확인하였다. 본 연구는 주거우울을 측정할 수 있는 새로운 도구를 제안하여 투사기법을 이용한 심리 진단 연구의 발판을 제공한데 그 의의를 찾을 수 있다.

• 한국컴퓨터정보학회논문지
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• 제11권2호
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• pp.169-175
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• 2006

본 논문은 고정된 카메라를 수평 이동(panning)시켜 얻어진 영상으로부터 단순화된 변환식을 이용 실린더 파노라마 영상(cylindrical panorama)을 재구성하는 방법을 제안한다. 일반적인 영상간의 사영 변환식(projective transform)은 3차원 공간의 X, Y, Z축에 대한 카메라의 회전 성분을 모두 고려하지만, 실제 파노라마 영상을 구성하기 위해서는 Y축 중심의 카메라 회전만을 고려한다. 이러한 제약은 기존의 8자유도(degree of freedom)를 갖는 사영 변환식을 4자유도를 갖는 사영 변환식으로 단순화시키고, 그 결과 변환식을 유도하기 위해 필요한 대응점의 개수가 절반으로 줄어들어 전체적인 계산량을 크게 감소시킬 수 있다. 모의실험 결과 제안된 알고리즘은 기존의 알고리즘과 계산량을 감소시키면서 유사한 성능을 보이고 있고, 단순화된 사영 변환식을 이용한 영상을 구성하는 것을 보여주었다.

• International Journal of Advanced Culture Technology
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• 제6권4호
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• pp.323-330
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• 2018

The growth of the older population is expected to further increase social problems associated with population aging, such as isolation, poverty, and depression. The emerging issues associated with the older population are also expected to provide further momentum on studies about the dwelling environment as factors that ensure the health of older people as well as improve their quality of life. Therefore, approaches for explaining the issues of the older age group should be diversified using a variety of factors and appropriate analytic tools. Studies on measuring depression have principally focused on assessing an objective self-report questionnaire, usually in a highly structured, textual form which may not reflect the cognitive impairment of older adults. The aim of this study was to define and measure dwelling depression among older adults in Korea. There are two specific hypotheses in this study as follows: (a) there will be statistically significant relationships with dwelling dissatisfaction and depression, and (b) dwelling depression tools containing text and images will be, respectively, assessment tools that have a good construct with content validity and reliability. In the first experiment, to define and measure dwelling depression, 301 people over 65 years old living in single and two-person households were surveyed using a text-based dwelling depression questionnaires from September 1-30, 2017. In the second experiment, to examine whether the projective image questionnaire could serve as a suitable replacement for the text-based questionnaires, the same participants were surveyed from January 22 to February 2, 2018. The results show that depression has a close correlation with dwelling dissatisfaction. In addition, the geriatric dwelling depression index (GDDI) based on the projective image was refined. Additionally, the projective image questionnaire has a close correlation with the text-based questionnaire. Finally, through ROC curve analysis, it was found that the projective image questionnaire can accurately predict a depression group. To this end, this preliminary study examined the validity of the projective image questionnaire in older adults to make this instrument feasible for older populations and to contribute to a profound understanding of geriatric depression due to the living environment. We hope they will provide a basis for further research on psychological diagnoses using projective images.