• 대한수학회보
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• 제51권4호
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• pp.979-994
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• 2014

We study half lightlike submanifold M of an indefinite trans-Sasakian manifold such that its structure vector field is tangent to M. First we study the general theory for such half lightlike submanifolds. Next we prove some characterization theorems for half lightlike submanifolds of an indefinite generalized Sasakian space form.

• 대한수학회보
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• 제50권3호
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• pp.1041-1048
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• 2013

In this paper, we study the curvature of a semi-Riemannian manifold $\tilde{M}$ of quasi-constant curvature admits some half lightlike submanifolds M. The main result is two characterization theorems for $\tilde{M}$ admits extended screen homothetic and statical half lightlike submanifolds M such that the curvature vector field of $\tilde{M}$ is tangent to M.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1205-1206
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• 2008

In the conventional floating display system some image distortions might be occurred in the floating image plane, in which a flat screen has been mostly used for providing an adequate input image plane. In this paper, as a new approach to alleviate image distortion problem in a floating display system, a curved screen is suggested by through some computer simulation using an optics design program of Light Tools.

• 대한수학회논문집
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• 제27권1호
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• pp.185-195
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• 2012

We study the geometry of lightlike hypersurfaces M of an inde nite cosymplectic manifold $\bar{M}$ such that either (1) the characterist vector field $\zeta$ of $\bar{M}$ belongs to the screen distribution S(TM) of M or (2) $\zeta$ belongs to the orthogonal complement $S(TM)^{\perp}$ of S(TM) in $T\bar{M}$.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제19권3호
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• pp.211-228
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• 2012

We study lightlike submanifolds M of a semi-Riemannian manifold $\bar{M}$ with a semi-symmetric non-metric connection subject to the conditions; (a) the characteristic vector field of $\bar{M}$ is tangent to M, (b) the screen distribution on M is totally umbilical in M and (c) the co-screen distribution on M is conformal Killing.

• 호남수학학술지
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• 제35권3호
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• pp.329-342
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• 2013

We study lightlike hypersurfaces M of a semi-Riemannian space form $\tilde{M}(c)$ with a semi-symmetric non-metric connection whose structure vector field is tangent to M. Our main result is two characterization theorems for such a lightlike hypersurface.

• Kyungpook Mathematical Journal
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• 제51권2호
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• pp.125-138
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• 2011

We give some characterizations of non-existence of lightlike hypersurfaces of an indefinite space form. Some geometric objects for the induced Ricci tensor to be symmetric are studied.

• 대한수학회논문집
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• 제28권4호
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• pp.809-818
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• 2013

We study irrotational half lightlike submanifolds M of a semi-Riemannian space form with a semi-symmetric non-metric connection such that its structure vector field is tangent to M. We prove two characterization theorems for such an irrotational half lightlike submanifold.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.668-671
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• 1999

The gene encoding Schwanniomyces occidentalis $\alpha-amylase$(AMY) was introduced into Saccharomyces cerevisiae var. diastaticus which secreted only glucoamylase, by using a linearized yeast integrating vector to develop stable strains with a capability of secreting $\alpha-amylase$and glucoamylase simultaneously. A dominant selectable marker, the geneticin(G418) resistance gene (Gt^r$), was cloned into a vector to screen wild-type diploid transformants harboring the AMY gene. The amylolytic activities of transformants were about 3-7 times higher than those of the recipient strains. When grown in nonselective media, the transformants with the linearized integrating vector containing the AMY gene exhibited almost all of the mitotic stability after 100 generations.

• Spatial Information Research
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• 제8권1호
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• pp.69-83
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• 2000

지적도면은 매 필지별로 토지에 대한 지번, 위치, 경RP , 소유권등을 규정하고 있는 토지에 관한 가장 기본적인 자료이다. 지적과 관련된 업무는 그 동안 거의 수작업에 의한 방법을 사용하여 효율성의 문제가 대두되었다. 따라서 정부에서는 지적도면을 전산화하려 하였으며, 토지 및 임야대장에 대한 속성정보를 모두 전산 입력하였다. 그러나 도형정보인 지적도면의 전산화가 이루어지지않아 효율적인 토지정보시스템 구축에 많은 어려움이 있다. 따라서 본 연구에서는 오차가 허용될 수 없는 지적도면의 특성을 감안하여 , 스크린 디지타이징을 원형(prototype) 으로 하고 작업의 효율성을 위해 선의 교점을 찾는 과정을 선추적 방식을 통해 자동화한, 혼합형(hybrid) 벡터라이징 방식을 개발하였다. 개발된 프로그램을 구동한 결과 백터라이징의 정확도에 있어서는 스크린 디지타이징 방법과 동일하였고, 효율성 측면에서는 본 프로그램에 의한 방법이 스크린 디지타이징 방법보다 35분 정도 시간을 단축할 수 있었다.